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Tamilnadu Samacheer Kalvi 11th Bio Zoology Solutions Chapter 7 Body Fluids and Circulation

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Samacheer Kalvi 11th Bio Zoology Body Fluids and Circulation Text Book Back Questions and Answers

I. Multiple Choice Questions
Question 1.
What is the function of lymph?
(a) Transport of O₂ into brain
(b) Transport of CO₂ into lungs
(c) Bring interstitial fluid in blood
(d) Bring RBC and WBC in lymph node
Answer:
(c) Bring interstitial fluid in blood

Question 2.
Which one of the following plasma proteins is involved in the coagulation of blood?
(a) Globulin
(b) Fibrinogen
(c) Albumin
(d) Serum amylase
Answer:
(b) Fibrinogen

Question 3.
Which of the following WBCs are found in more numbers?
(a) Eosinophil
(b) Neutrophil
(c) Basophil
(d) Monocyte
Answer:
(b) Neutrophil

Question 4.
Which of the following is not involved in blood clotting?
(a) Fibrin
(b) Calcium
(c) Platelets
(d) Bilirubin
Answer:
(d) Bilirubin

Question 5.
Lymph is colourless because ………….
(a) WBC are absent
(b) WBC are present
(c) Haemoglobin is absent
(d) RBC are absent
Answer:
(c) Haemoglobin is absent

Question 6.
Blood group is due to the presence or absence of surface
(a) Antigens on the surface of WBC
(b) Antibodies on the surface of RBC
(c) Antigens on the surface of RBC
(d) Antibodies on the surface of WBC
Answer:
(c) Antigens on the surface of RBC

Question 7.
A person having both antigen A and antigen B on the surface of RBCs belongs to blood group
(a) A
(b) B
(c) AB
(d) O
Answer:
(c) AB

Question 8.
Erythroblastosis foetalis is due to the destruction of …………..
(a) Foetal RBCs
(b) Foetus suffers from atherosclerosis
(c) Foetal WBCs
(d) Foetus suffers from mianmata
Answer:
(a) Foetal RBCs

Question 9.
Dub sound of heart is caused by
(a) Closure of atrio-ventricular valves
(b) Opening of semi-lunar valves
(c) Closure of semi-lunar valves
(d) Opening of atrio-ventricular valves
Answer:
(c) Closure of semi-lunar values

Question 10.
Why is the velocity of blood flow the lowest in the capillaries?
(a) The systemic capillaries are supplied by the left ventricle, which has a lower cardiac output than the right ventricle.
(b) Capillaries are far from the heart, and blood flow slows as distance from the heart increases.
(c) The total surface area of the capillaries is larger than the total surface area of the arterioles.
(d) The capillary walls are not thin enough to- allow oxygen to exchange with the cells.
(e) The diastolic blood pressure is too low to deliver blood to the capillaries at a high flow rate.
Answer:
(c) The total surface area of the capillaries is larger than the total surface area of the arterioles.

Question 11.
An unconscious patient is rushed into the emergency room and needs a fast blood transfusion. Because there is no time to check her medical history or determine her blood type, which type of blood should you as her doctor, give her?
(a) A⁺
(b) AB
(c) O⁺
(d) O^–
Answer:
(c) O⁺

Question 12.
Which of these functions could or could not be carried out by a red blood cell?
(a) Protein synthesis
(b) Cell division
(c) Lipid synthesis
(d) Active transport
Answer:
(a) Protein synthesis: RBCs do not have ribosomes which are important for protein synthesis, They are concerned with transport of respiratory gases alone. Hence protein synthesis
could not take place in RBCs.

(b) Cells division: RBCs do not have numbers. They are produced in the bone marrow. They do not involve in cell division.

(c) Lipid Synthesis: Lipid synthesis occurs in endoplasmic reticulum (ER) and golgi complex. The ER is absent in RBCs. Hence lipid synthesis does not take place in RBCs.

(d) Active transport: Transport of respiratory gases between the alveoli to the blood vessels, blood vessel to the cells and vice versa take place due to difference in the partial pressure of O₂ and CO₂., Active transport of materials against concentration gradient does not take place in RBCs.

Question 13.
At the venous end of the capillary bed, the osmotic pressure is …………….
(a) Greater than the hydrostatic pressure
(b) Result in net outflow of fluids
(c) Results in net absorption of fluids
(d) No change occurs
Answer:
(a) Greater than the hydrostatic pressure

Question 14.
A patient’s chart reveals that he has a cardiac output of 7500mL per minute and a stroke volume of 50 mL. What is his pulse rate (in beats / min)
(a) 50
(b) 100
(c) 150
(d) 400
Answer:
(c) 150

Question 15.
At any given time there is more blood in the venous system than that of the arterial system. Which of the following features of the veins allows this?
(a) relative lack of smooth muscles
(b) presence of valves
(c) proximity of the veins to lymphatic’s
(d) thin endothelial lining
Answer:
(a) relative lack of smooth muscles

II. Short Answer Questions

Question 16.
Distinguish between arteries and veins?
Answer:

Arteries	Veins
1. Arteries are the blood vessels that carry blood away from the heart.	1. Veins are the blood vessels that carry blood to the heart.
2. Arteries carry oxygenated blood except pulmonary artery.	2. Veins carry deoxygenated blood except pulmonary veins.
3. Arteries usually lie deep inside the body.	3. Veins are usually located superficially.
4.  These are thick walled.	4. These are thin walled.
5. These do not have valves.	5. These have semilunar valves.
6. Blood pressure is high.	6.  Blood pressure is low.

Question 17.
Distinguish between open and closed circulation?
Answer:

Open circulation	Closed circulation
1. Open circulation, haemolymph is pumped by the heart which flows through blood vessels into the haemocoel.	1.In closed circulation, blood is pumped by the heart and flows through blood vessels
2. It is seen in arthropods and most molluscs.	2. It is seen in annelids, cephalopods and vertebrates

Question 18.
Distinguish between mitral valve and semi lunar valve?
Answer:

Mitral valve	Semilunar vales
1. The valve present between the left atrium left ventricle is called mitral valve.	1. The valves present at the openings of right and left ventricles into the pulmonary artery and aorta are semilunar valves.
2. It is made of two flaps.	2. These are of three half moon shaped cusps.

Question 19.
Right ventricular wall is thinner than the left ventricular wall. Why?
Answer:
The right ventricle pumps deoxygenated blood, to the lungs through pulmonary artery. The left ventricle pumps the oxygenated blood to all parts of the body through the aorta. Hence, left ventricle has to exert more pressure. Hence right ventricular wall is thinner but the left ventricular walls is thicker.

Question 20.
What might be the effect on a person whose diet has less iron content?
Answer:
A person whose diet has less iron content will become anaemic. The haemoglobin content of the blood will be less. The volume of oxygen carried by RBCs gets reduced. He/she may experience tiredness, weakness, fatigue etc. In order to overcome this deficiency one has to take iron rich diet.

Question 21.
Describe the mechanism by which the human heart beat is initiated and controlled?
Answer:
The rhythmic contraction and expansion of heart is called heart beat. The contraction of the heart is called systole and the relaxation of the heart is called diastole. The human heart is myogenic. The pacemaker cells are located in the right sinoatrial (SA) node.

On the left side of the right atrium, there is a mode called auriculo ventricular node (AV). Two special cardiac muscle fibres which originate from the AV node are called the bundle of His. It runs down into the interventricular spectrum and the fibres spread into the ventricle as the Purkinje fibres.

The pacemaker cells produce excitation through depolarization of their cell membrane. Early depolarization is slow and takes place by sodium influx and reduction in potassium efflux. Minimum potential is required to activate voltage gated calcium (Ca⁺) channels that cause rapid depolarization which results in action potential. The pace maker cells repolarise slowly via K⁺ efflux.

Question 22.
What is lymph? Write its function?
Answer:
About 90% of fluid that leaks from capillaries eventually seeps back into the capillaries and the remaining 10% is collected and returned to blood system by me of a series of tubules known as lymph vessels or lymphatics.

The fluid inside the lymphatics is called lymph. The lymphatic system consists of a complex network of thin walled ducts (lymphatic vessels), filtering bodies (lymph nodes) and a large number of lymphocytic cell concentrations in various lymphoid organism.

The lymphatic vessels have smooth walls that run parallel to the blood vessels, in the skin, along the respiratory and digestive tracts. These vessels serve as return ducts for the fluids that are continually diffusing out of the blood capillaries into the body tissues.

Lymph fluid must pass through the lymph nodes before it is returned to the blood. The lymph nodes that filter the fluid from the lymphatic vessels of the skin are highly concentrated in the neck, inguinal, axillaries, respiratory and digestive tracts.

The lymph fluid flowing out of the lymph nodes flow into large collecting duct which finally drains into larger veins that runs beneath the collar bone, the subclavian vein and is emptied into the blood stream. The narrow passages in the lymph nodes are the sinusoids that are lined with macrophages.

The lymph nodes successfully prevent the invading microorganisms from reaching the blood stream. Cells found in the lymphatics are the lymphocytes. Lymphocytes collected in the lymphatic fluid are carried via the arterial blood and are recycled back to the lymph. Fats are absorbed through lymph in the lacteals present in the villi of the intestinal wall.

Question 23.
What are the heart sounds? When and how are these sounds produced?
Answer:
Rhythmic contraction and expansion of heart is called heart beat. The contraction of the heart is called systole and the relaxation of the heart is called diastole. The heart normally beats 70-72 times per minute in a human adult. During each cardiac cycle two sounds are produced that can be heard through a stethoscope.

The first heart sound (lub) is associated with the closure of the tricuspid and bicuspid valves whereas Second heart sound (dub) is associated with the closure of the semilunar valves. These sounds are of clinical diagnostic significance. An increased heart rate is called tachycardia and decreased heart rate is called bradycardia.

Question 24.
Select the correct biological term. Lymphocytes, red cells, leucocytes, plasma, erythrocytes, white cells, haemoglobin, phagocyte, platelets, blood clot?

Question (a)
Disc shaped cells which are concave on both sides?
Answer:
Red blood cells

Question (b)
Most of these have a large, bilobed nucleus?
Answer:
Leucocytes

Question (c)
Enable red cells to transport blood?
Answer:
Haemoglobin

Question (d)
The liquid part of the blood?
Answer:
plasma

Question (e)
Most of them move and change shape like an amoeba?
Answer:
phagocyte

Question (f)
Consists of water and important dissolved substances?
Answer:
plasma

Question (g)
Destroyed in the liver and spleen after circulating in the blood for four months?
Answer:
RBCs

Question (h)
The substances which gives red colour to their cells?
Answer:
haemoglobin

Question (i)
Another name for red blood cells?
Answer:
Erythrocytes

Question (j)
Blood that has been changed to a jelly?
Answer:
Blood clot

Question (k)
A word that me cell eater?
Answer:
Phagocyte

Question (l)
Cells without nucleus?
Answer:
Red blood cells

Question (m)
White cells made in the lymphatic tissue?
Answer:
Lymphocytes

Question (n)
Blocks wound and prevent excessive bleeding?
Answer:
Platelets

Question (o)
Fragment of cells which are made in the bone marrow?
Answer:
Erythrocytes

Question (p)
Another name for white blood cells?
Answer:
Leucocytes

Question (q)
Slowly releases oxygen to blood cells?
Answer:
Red cells

Question (r)
Their function is to help blood clot in wounds?
Answer:
Platelets

Question 25.
Select the correct biological term?
Answer:
Cardiac muscle, atria, tricuspid valve, systole, auricles, arteries, diastole, ventricles, bicuspid valve, pulmonary artery, cardiac cycle, semi lunar valve, veins, pulmonary vein, capillaries, vena cava, aorta?

Question (a)
The main artery of the blood?
Answer:
Aorta

Question (b)
Valves between the left atrium and ventricle?
Answer:
Bicuspid valve

Question (c)
Technical name for relaxation of the heart?
Answer:
Diastole

Question (d)
Another name for atria?
Answer:
Arteries

Question (e)
The main vein?
Answer:
Vena cava

Question (f)
Vessels which carry blood away from the heart?
Answer:
Arteries

Question (g)
Two names for the upper chambers of the heart?
Answer:
Atria

Question (h)
Thick walled chambers of the heart?
Answer:
Atria

Question (i)
Carries blood from the heart to the lungs?
Answer:
Pulmonary Artery

Question (j)
Takes about 0.8 sec to complete?
Answer:
Cardiac cycle

Question (k)
Valves situated at the point where blood flows out of the heart?
Answer:
Semilunar values

Question (l)
Vessels which carry blood towards the heart?
Answer:
Veins

Question (m)
Carries blood from the lungs to the heart?
Answer:
Pulmonary veins

Question (n)
The two lower chambers of the heart?
Answer:
Ventricles

Question (o)
Prevent blood from re-entering the ventricles after entering the aorta?
Answer:
Semilunar valves

Question (p)
Technical name for one heart beat?
Answer:
Cardiac cycle

Question (q)
Valves between right atrium and ventricles?
Answer:
Tricuspid valve

Question (r)
Technical name for contraction of the heart?
Answer:
Systole

Question (s)
Very narrow blood vessels?
Answer:
Capillaries

Question 26.
Name and label the given diagram to show A, B, C, D, E, F, and G?
(A) Aorta
(B) Pulmonary trunk
(C) Left pulmonary veins
(D) Blocking the action of vasoconstrictor lowers the blood pressure. Give reasons.
(E) What is the role of ACH inhibitor in reducing blood pressure?
(F) What conditions one might expect if the blood pressure is not controlled?
Answer:
(A) Aortic arch
(B) Left pulmonary artery
(C) Left pulmonary veins
(D) Pulmonary trunk
(E) Left ventricle
(F) Right ventricle
(G) Inferior vena cava

Samacheer Kalvi 11th Bio Zoology Body Fluids and Circulation Additional Questions & Answers

I. Multiple Choice Questions
Choose The Correct Answer

Question 1.
Which of the following is not the function of circulatory system?
(a) Transport of respiratory gases
(b) Carrying of digested food materials
(c) Transport of hormones to target organism
(d) Removal of nitrogenous wastes from the body
Answer:
(d) Removal of nitrogenous wastes from the body

Question 2.
Which is known as liquid connective tissue?
(a) Plasma
(b) Blood
(c) Serum
(d) lymph
Answer:
(b) blood

Question 3.
What is the function of albumin?
(a) Transport of hormones
(b) Blood clothing
(c) Maintenance of osmotic pressure
(d) Immunity
Answer:
(c) Maintenance of osmotic pressure

Question 4.
Fibrinogen is concerned with ………….
(a) Transport of ions
(b) Tranport of liquids
(c) Transport of hormones
(d) Coagulaltion of blood
Answer:
(d) Coagulation of blood

Question 5.
The red colour of the RBC is due to the presence of a respiratory pigment ……………
(a) Haemoerythrin
(b) Haemoglobin
(c) Haemocyanin
(d) Chlorocronin
Answer:
(b) Haemoglobin

Question 6.
Which of the following are non-nucleated cells?
(a) WBCs
(b) Nerve cell
(c) RBCs
(d) Muscle cell
Answer:
(c) RBCs

Question 7.
What is haematocrit/packed cells volume?
(a) The ratio of WBCs to blood plasma
(b) The ratio of RBCs to blood plasma
(c) The ratio of platelets to blood plasma
(d) The ratio of plasma and blood cells
Answer:
(b) The ratio of RBCs to blood plasma

Question 8.
Which of the following is abundant in blood?
(a) Neutrophils
(b) Eosinophils
(c) Basophils
(d) Lymphocytes
Answer:
(a) Neutrophils

Question 9.
…………… are the blood cells which have two lobes which are joined by thin strands.
(a) Neutrophils
(b) Basophils
(c) Eosinophils
(d) Lymphocytes
Answer:
(c) Eosinophils

Question 10.
What is the percentage of lymphocytes among WBCs?
(a) 0.5 to 1.0%
(b) 1-3%
(c) 65%
(d) 28%
Answer:
(d) 28%

Question 11.
The macrophages in the sinusoids of the liver are called ………….
(a) Microglia
(b) Kupffer cells
(c) Alveolar macrophages
(d) Lymphocytes
Answer:
(b) Kupffer cells

Question 12.
‘A’ blood group has ………………….. antigen and …………………. antibody
(a) A, anti B
(b) AB, no antibodies
(c) No antigen, anti A, Anti B
(d) B, Anti A
Answer:
(d) B, Anti A

Question 13.
Erythroblastosis foetalis is a condition of incompatibility related to ……………..
(a) Rh antigen and Rh antibodies
(b) Anti A and antigen B
(c) Anti B and antigen A
(d) Antigens A and B
Answer:
(a) Rh antigen and Rh antibodies

Question 14.
The conversion of prothrombin into thrombin occurs in the presence of ……………..
(a) Potassium and vitamin D
(b) Sodium and vitamin B,2
(c) Calcium and vitamin K
(d) Iodine and vitamin E
Answer:
(c) Calcium and vitamin K

Question 15.
………………….. is the exceptional artery which carries deoxygenated blood.
(a) Pulmonary artery
(b) Corotid artery
(c) Coronary artery
(d) Femoral artery
Answer:
(a) Pulmonary artery

Question 16.
Pulmonary veins carry ………………. blood from lungs to ……………….
(a) Oxygenated, right auricle
(b) Deoxygenated, right auricle
(c) Deoxygenated, left auricle
(d) Oxygenated, left auricle
Answer:
(c) Deoxygenated, left auricle

Question 17.
The blood vessels that supply blood to the cardiac muscles with all nutrients are
(a) Coronary arteries
(b) Cerebral arteries
(c) Aorta
(d) Pulmonary veins
Answer:
(a) Coronary arteries

Question 18.
The opening between the left atrium and left ventricle is guarded by …………….
(a) Semilunar valves
(b) Mitral valve
(c) Tricuspid valve
(d) Flaps
Answer:
(b) Mitral valve

Question 19.
The heart normally beats times …………………. per minute in a human adult.
(a) 60-62
(b) 50-52
(c) 70-72
(d) 90-92
Answer:
(c) 70-72

Question 20.
Which wave shape occurs from the start of depolarisation of the atria to the beginning of ventricular depolarisation?
(a) P wave
(b) ST segment
(c) QRS complex
(d) PQ interval
Answer:
(d) PQ interval

Question 21.
In systemic circulation, blood from the …………………. ventricle is carried by a network of arteries, arterioles and capillaries to the tissues.
(a) Deoxygenated right
(b) Oxygenated left
(c) Oxygenated right
(d) Deoxygenated left
Answer:
(b) Oxygenated, left

Question 22.
Which hormone increases the heart beat?
(a) Acetylcholine
(b) Gastrin
(d) Epinephrine
(d) Oxytocin
Answer:
(c) Epinephrine

Question 23.
Thrombus in a coronary artery results in ………….
(a) Heart attack
(b) Stroke
(c) Hypertension
(d) Heart failure
Answer:
(a) Heart attack

Question 24.
Cerebral infarction is called ……….
(a) Heart attack
(b) Hypertension
(c) Heart failure
(d) Stroke
Answer:
(d) Stroke

Question 25.
The failure of the heart to pump out the normal stroke volume is a condition called ………….
(a) Cerebral thrombosis
(b) Hypertension
(c) Myocardial infarction
(d) Rheumatoid heart disease
Answer:
(c) Myocardial infarction

Question 26.
In which condition the heart muscles do not get oxygen supply?
(a) Stroke
(b) Ischemic heart disease
(c) Hypertension
(d) Heart attack
Answer:
(b) Ischemic heart disease

Question 27.
Which of the following is the autoimmune disease that damages the heart?
(a) Ischemic heart disease
(b) Myocardial infarction
(c) Cerebral thrombosis
(d) Rheumatic fever
Answer:
(d) Rheumatic fever

Question 28.
The life saving procedure, CPR was first used by ……………
(a) William Harvey
(b) Carl Landsteiner
(c) James Elam and Peter Safar
(d) Raymond de Viessens
Answer:
(c) James Elam and Peter Safar

II. Fill in the Blanks

Question 1.
The tissue fluid that surrounds the cell is ………..
Answer:
Interstitial fluid.

Question 2.
The fluid component of the blood is …………
Answer:
Plasma

Question 3.
The blood flowing into the capillary from an arteriole has a high …………. pressure.
Answer:
Hydrostatic

Question 4.
………….. is the plasma protein that facilitates the transport of ions, hormones, lipids and assists in immune function.
Answer:
Globulin

Question 5.
………….. is the respiratory pigment that facilitates the transport of gases.
Answer:
Haemoglobin

Question 6.
The RBCs are destroyed in the liver and ………….
Answer:
Spleen

Question 7.
………….. is the hormone that helps in differentiation of stem cells of bone marrow into erythrocytes.
Answer:
Erythropoietin

Question 8.
The ratio of red blood cells to blood plasma is expressed is …………
Answer:
Haematocrit

Question 9.
The granulocytes have in the cytoplasm.
Answer:
Granules

Question 10.
Neutrophils are also called …………
Answer:
Heterophils/polymorpho nuclear cells

Question 11.
…………… have distinctly dilobed nucleus and the lobes are joined by thin strands.
Answer:
Eosinophils

Question 12.
Basophils secrete substances such as ……………… serotonin and histones.
Answer:
Heparin

Question 13.
The macrophages of the central nervous system are the ………….
Answer:
Microglia

Question 14.
Platelets are produced from ………….
Answer:
Megakaryocytes

Question 15.
Surface antigens of RBCs are called …………..
Answer:
Agglutinogens

Question 16.
The ………………… acting on agglutinogen B is called anti B.
Answer:
Agglutinin

Question 17.
The condition called erythroblastosis foetalis can be avoided by administration of anti D antibodies called …………..
Answer:
Rhocum.

Question 18.
………………….. helps in the conversion of fibrinogen to fibrin threads.
Answer:
Thrombin

Question 19.
The plasma without fibrinogen is called …………
Answer:
Serum

Question 20.
The fluid inside lymphatics is called ………….
Answer:
Lymph

Question 21.
Lymphocytes collected in the lymphatic fluid are carried via the arterial blood and are recycled back to the ………….
Answer:
Lymph

Question 22.
Fats are absorbed through lymph in the present in the villi of the intestinal wall.
Answer:
Lacteals

Question 23.
The middle layer of the artery is composed of smooth muscles and an extra cellular matrix which contains a protein ……………
Answer:
Elastin

Question 24.
The tunica adventitia of the artery is composed of ………………………. fibres.
Answer:
Collagen

Question 25.
The blood vessels that carry blood away from the heart are called …………..
Answer:
Arteries

Question 26.
All arteries carry oxygenated blood except …………..
Answer:
Pulmonary artery

Question 27.
……………………….. are small, narrow, and thin walled which are connected to the capillaries.
Answer:
Arterioles.

Question 28.
The …………………….. are the site for exchange of materials between blood and tissues.
Answer:
Capillaries

Question 29.
The unidirectional flow of blood in veins is due to the presence of that prevents back flow of blood.
Answer:
Semi lunar valves

Question 30.
Blood vessels that supply blood to the cardiac muscles are …………..
Answer:
Coronary arteries

Question 31.
…………………….. circulatory system is seen in Arthropoda and most molluscs.
Answer:
Open

Question 32.
The right atrium receives blood.
Answer:
Oxygenated.

Question 33.
The left atrium receives ………………….. blood.
Answer:
Deoxygenated

Question 34.
The crocodile has a ……………………. chambered heart.
Answer:
Four

Question 35.
…………………….. guards the opening between the left atrium and left ventricle.
Answer:
Bicuspid valve/mitral valve

Question 36.
The myocardium of the ventricle is thrown into irregular muscular ridges called ……………
Answer:
Trabeculae cornea

Question 37.
The heart wall is made up of outer epicardium, middle myocardium and the inner …………..
Answer:
Endocardium

Question 38.
The heart is covered by a double membrane called ……………
Answer:
Pericardium

Question 39.
On the left side of the right atrium there is a node called ………….
Answer:
Auriculo ventricular node

Question 40.
The rhythmic contraction and expansion of heart is called ……………
Answer:
Heart beat

Question 41.
The contraction of the chambers of the heart is called ……………
Answer:
Systole

Question 42.
The relaxation of the chambers of the heart is called …………..
Answer:
Diastole

Question 43.
The ‘lub’ sound is associated with the closure of the ………………….. valves.
Answer:
Tricuspid and bicuspid

Question 44.
The ‘dub’ sound is associated with the closure of ……………………… valves.
Answer:
Semilunar

Question 45.
An increased heart beat is called ………….
Answer:
Tachycardia

Question 46.
The decreased heart beat is called ………….
Answer:
Bradycardia

Question 47.
The phase I of the cardiac cycle is called …………..
Answer:
Ventricular diastole

Question 48.
The ventricular systole is the …………………….. phase of the cardiac cycle.
Answer:
Third

Question 49.
The amount of blood pumped out by each ventricle per minute is called …………
Answer:
Cardiac output

Question 50.
……………………. is the number of beats of the heart per minute.
Answer:
Heart rate/pulse rate

Question 51.
………………………. is the volume of blood pumped out by one ventricle with each beat.
Answer:
Stroke volume

Question 52.
If the right side of the heart fails, it results in …………………… congestion.
Answer:
Peripheral

Question 53.
Frank-Startling effect protects the heart from abnormal increase in …………..
Answer:
Blood volume

Question 54.
………………………. is the pressure exerted on the surface of blood vessels by the blood.
Answer:
Blood pressure

Question 55.
……………………. is the pressure in the arteries as the chambers of the heart contracts.
Answer:
Systolic pressure

Question 56.
……………………… is the pressure in the arteries when the heart chambers relax.
Answer:
Diastolic pressure

Question 57.
Blood pressure is measured using a ………………………… and a stethoscope.
Answer:
Sphygmomanometer

Question 58.
The decrease in blood pressure upon standing is known as ……………………….. hypertension.
Answer:
Orthostatic

Question 59.
Orthostatic reflex triggers baroreceptor reflex and increases the mean …………
Answer:
Arterial pressure

Question 60.
Circulation of the blood was first described by …………..
Answer:
William Harvey

Question 61.
In …………………….. circulation, the blood from heart is taken to the lungs by pulmonary artery and the oxygenated blood from the lungs is emptied into the left auricle by the pulmonary vein.
Answer:
Pulmonary

Question 62.
Vasopressin and ………………………… are involved in the regulation of the kidneys results in vasoconstriction.
Answer:
Angiotensin II

Question 63.
Coronary heart disease occurs when the arteries are lined by …………..
Answer:
Atheroma

Question 64.
Uncontrolled hypertension may damage the heart, brain and ………….
Answer:
Kidneys

Question 65.
The cholesterol rich atheroma forms …………………… in the inner lining of the arteries making them less elastic.
Answer:
Plaques

Question 66.
………………………. in a caronary artery results in heart attack.
Answer:
Thrombus

Question 67.
Brain haemorrhage is a condition known as ………….
Answer:
Stroke.

Question 68.
The condition in which the part of the brain tissue that is supplied by damaged artery dies due to lack of oxygen is …………….
Answer:
Cerebral infarction

Question 69.
Ischemic pain in the heart muscles is called ………….
Answer:
Angina pectoris

Question 70.
Atheroma may partially block the ……………………….. and reduce the blood supply to the heart.
Answer:
Coronary artery

Question 71.
The common sites of varicose veins are legs, rectal-anal regions, oesophagus and the …………
Answer:
Spermatic cord

Question 72.
The prime defect in heart failure is a decrease in cardiac muscle …………..
Answer:
Contractility

Question 73.
Prolonged angina leads to death of the heart muscle resulting in …………
Answer:
Heart failure

Question 74.
The death of the muscle fibres of the heart due to reduced blood supply to the heart muscle is called …………..
Answer:
Myocardial infarction

Question 75.
……………………… is an autoimmune disease which occurs 2-4 weeks after streptococcal throat infection.
Answer:
Rheumatic heart disease

Question 76.
………………….. me a brief electric shock given to the heart to recover the function of the heart.
Answer:
Defibrillation

III. Answer The Following Questions

Question 1.
What are the two types of body fluids?
Answer:
The intra-cellular fluid present inside the cells and the extracellular fluid present outside the cells are the two types of body fluids.

Question 2.
What are the three types of extra-cellular fluids?
Answer:
The three types of extra-cellular fluids are the interstitial fluid, the plasma and lymph.

Question 3.
Explain the composition of blood?
Answer:
Blood is the most common body fluid that transports substances from one part of the body to the other. Blood is a connective tissue consisting of plasma (fluid matrix) and formed elements.

The plasma constitutes 55% of the total blood volume. The remaining 45% is the formed elements that consist of blood cells. The average blood volume is about 5000 ml (5L) in an adult weighing 70 Kg.

Plasma:
Plasma mainly consists of water (80 – 92%) in which the plasma proteins, inorganic constituents (0.9%), organic constituents (0.1%) and respiratory gases are dissolved.

The four main types of plasma proteins synthesized in the liver are albumin, globulin, prothrombin and fibrinogen. Albumin maintains the osmotic pressure of the blood. Globulin facilitates the transport of ions, hormones, lipids and assists in immune function.

Both Prothrombin and Fibrinogen are involved in blood clotting. Organic constituents include urea, amino acids, glucose, fats and vitamins; and the inorganic constituents include chlorides, carbonates and phosphates of potassium, sodium, calcium and magnesium.

The composition of plasma is always constant Immediately after a. meal, the blood in the hepatic portal vein has a very high concentration of glucose as it is transporting glucose from the intestine to the liver where it is stored.

The concentration of the glucose in the blood gradually falls after sometime as most of the glucose is absorbed. If too much of protein is consumed, the body cannot store the excess amino acids formed from the digestion of proteins.

The liver breaks down the excess amino acids and produces urea. Blood in the hepatic vein has a high concentration of urea than the blood in other vessels namely, hepatic portal vein and hepatic artery.

Formed elements:
Red blood cells/corpuscles (erythrocytes), white blood cells/corpuscles (Leucocytes) and platelets are collectively called formed elements.

Red blood cells:
Red blood cells are abundant than the other blood cells. There are about 5 million to 5.5 millions of RBC mnr3 of blood in a healthy man and 4.5-5.0 millions of RBC mm ° in healthy women.

The RBCs are very small with the diameter of about 7 pm (micrometer). The structure of RBC is shown in Figure. The red colour of the RBC is due to the presence of a respiratory pigment, haemoglobin dissolved in the cytoplasm.

Flaemoglobin plays an important role in the transport of respiratory gases and facilitates the exchange of gases with the fluid outside the cell (tissue fluid). The biconcave shaped RBCs increases the surface area to volume ratio, hence oxygen diffuses quickly in and out of the cell.

The RBCs are devoid of nucleus, mitochondria, ribosomes and endoplasmic reticulum. The absence of these organelles accommodates more haemoglobin thereby maximising the oxygen carrying capacity of the cell.

The average life span of RBCs in a healthy individual is about 120 days after which they are destroyed in the spleen (graveyard/cemetery of RBCs) and the iron component returns to the bone marrow for reuse.

Erythropoietin is a hormone secreted by the kidneys in response to low oxygen and helps in differentiation of stem cells of the bone marrow’ to erythrocytes (erythropoiesis) in adults. The ratio of red blood cells to blood plasma is expressed as Haematocrit (packed cell volume).

White blood cells:
(leucocytes) are colourless, amoeboid, nucleated cells devoid of haemoglobin and other pigments. Approximately 6000 to 8000 per cubic mm of WBCs are seen in the blood of an average healthy individual.

Depending on the presence or absence of granules, WBCs are divided into two types, granulocytes and agranulocytes. Granulocytes are characterised by the presence of granules in the cytoplasm and are differentiated in the bone marrow. The granulocytes include neutrophils, eosinophils and basophils.

Neutrophils are also called heterophils or polymorphonuclear (cells with 3-4 lobes of nucleus connected with delicate threads) cells which constitute about 60%-65% of the total WBCs. They are phagocytic in nature and appear in large numbers in and around the infected tissues.

Eosinophils have distinctly bilobed nucleus and the lobes are joined by thin strands. They are non-phagocytic and constitute about 2-3% of the total WBCs. Eosinophils increase during certain types of parasitic infections and allergic reactions.

Basophils are less numerous than any other type of WBCs constituting 0.5%-1.0% of the total number of leucocytes. The cytoplasmic granules are large sized, but fewer than eosinophils.

Nucleus is large sized and constricted into several lobes but not joined by delicate threads. Basophils secrete substances such as heparin, serotonin and histamines. They are also involved in inflammatory reactions.

Agranulocvtes are characterised by the absence of granules in the cytoplasm and are differentiated in the lymph glands and spleen. These are of two types, lymphocytes and monocytes. Lymphocytes constitute 28% of WBCs. These have large round nucleus and small amount of cytoplasm.

The two types of lymphocytes are B and T cells. Both B and T cells are responsible for the immune responses of the body. B cells produce antibodies to neutralize the harmful effects of foreign substances and T cells are involved in cell mediated immunity.

Monocytes (Macrophages) are phagocytic cells that are similar to mast cells and have kidney shaped nucleus. They constitute 1-3% of the total WBCs. The macrophages of the central nervous system are the ‘microglia’, in the sinusoids of the liver they are called ‘Kupffer cells’ and in the pulmonary region they are the ‘alveolar macrophages’.

Platelets are also called thrombocytes that are produced from megakaryocytes (special cells in bone marrow) and lack nuclei. Blood normally contains 1,50,000 – 3,50,000 platelets mm^-3 of blood. They secrete substances involved in coagulation or clotting of blood. The reduction in platelet number can lead to clotting disorders that result in excessive loss of blood from the body.

Question 4.
Explain the ABO blood groups?
Answer:
Depending on the presence or absence of surface antigens on the RBCs, blood group in individual belongs to four different types namely, A, B, AB and O. The plasma of A, B and O individuals have natural antibodies (agglutinins) in them.

Surface antigens are called agglutinogens. The antibodies (agglutinin) acting on agglutinogen A is called anti A and the agglutinin acting on agglutinogen B is called anti B.

Agglutinogens are absent in O blood group. Agglutinogens A and B are present in AB blood group and do not contain anti A and anti B in them. A, B and O are major allelic genes in ABO systems.

All agglutinogens contain sucrose, D-galactose, N-acetyl glucosamine and 11 terminal amino acids. The attachments of the terminal amino acids are dependent on the gene products of A and B. The reaction is catalysed by glycosyl transferanse.

Question 5.
Tabulate the distribution of antigens and antibodies is different blood groups?
Answer:
Distribution of antigens and antibodies in different blood groups:

Question 6.
Explain the role of Rh factor?
Answer:
Rh factor is a protein (D antigen) present on the surface of the red blood cells in majority (80%) of hum. This protein is similar to the protein present in Rhesus monkey, hence the term Rh. Individuals who carry the antigen D on the surface of the red blood cells are Rh⁺ (Rh positive) and the individuals who do not carry antigen D, are Rh^– (Rh negative). Rh factor compatibility is also checked before blood transfusion.

When a pregnant women is Rh⁺ and the foetus is Rh⁺ incompatibility (mismatch) is observed. During the first pregnancy, the Rh antigens of the foetus does not get exposed to the mother’s blood as both their blood are separated by placenta. However, small amount of the foetal antigen becomes exposed to the mother’s blood during the birth of the first child.

The mother’s blood starts to synthesize D antibodies. But during subsequent pregnancies the Rh antibodies from the mother (Rh^–) enters the foetal circulation and destroys the foetal RBCs. This becomes fatal to the foetus because the child suffers from anaemia and jaundice. This condition is called erythroblastosis foetalis. This condition can be avoided by administration of anti D antibodies (Rhocum) to the mother immediately after the first child birth.

Question 7.
Explain the process of coagulation of blood?
Answer:
If you cut your finger or when you get yourself hurt, your wound bleeds for some time after which it stops to bleed. This is because the blood clots or coagulates in response to trauma.

The mechanism by which excessive blood loss is prevented by the formation of clot is called blood coagulation or clotting of blood. The clotting process begins when the endothelium of the blood vessel is damaged and the connective tissue in its wall is exposed to the blood.

Platelets adhere to collagen fibres in the connective tissue and release substances that form the platelet plug which provides emergency protection against blood loss.

Clotting factors released from the clumped platelets or damaged cells mix with clotting factors in the plasma. The protein called prothrombin is converted to its active form called thrombin in the presence of calcium and vitamin K.

Thrombin helps in the conversion of fibrinogen to fibrin threads. The threads of fibrins become interlinked into a patch that traps blood cell and seals the injured vessel until the wound is healed.

After sometime fibrin fibrils contract, squeezing out a straw-coloured fluid through a meshwork called serum (Plasma without fibrinogen is called serum). Heparin is an anticoagulant produced in small quantities by mast cells of connective tissue which prevents coagulation in small blood vessels.

Question 8.
Explain the structure of blood vessels?
Answer:
The vessels carrying the blood are of three types; they are the arteries, veins and capillaries. These vessels are hollow structures and have complex walls surrounding the lumen. The blood vessels in hum are composed of three layers, tunica intima, tunica media and tunica externa.

The inner layer, tunica intima or tunica interna supports the vascular endothelium, the middle layer, tunica media is composed of smooth muscles and an extra cellular matrix which contains a protein, elastin. The contraction and relaxation of the smooth muscles results in vasoconstriction and vasodilation. The outer layer, tunica externa or tunica adventitia is composed of collagen fibres.

Arteries:
The blood vessels that carry blood away from the heart are called arteries. The arteries usually lie deep inside the body. The walls of the arteries are thick, non-collapsible to withstand high pressure. Valves are absent and have a narrow lumen. All arteries carry oxygenated blood, except the pulmonary artery.

The largest artery, the aorta (2.5 cm in diameter and 2 mm thick) branch into smaller arteries and culminates into the tissues as feed arteries. In the tissues the arteries branches into arterioles. As blood enters an arteriole it may have a pressure of 85 mm Hg (11.3 KPa) but as it leaves and flows into the capillary, the pressure drops to 35 mm Hg (4.7 KPa). (Note 1 mm Hg = 0.13 KPa.

SI unit of mm Hg is KiloPascal (KPa)). Arterioles are small, narrow, and thin walled which are connected to the capillaries. A small sphincter lies at the junction between the arterioles and capillaries to regulate the blood supply. Arteries do not always branch into arterioles, they can also form anastomoses.

Capillaries:
Capillary beds are made up of fine networks of capillaries. The capillaries are thin walled and consist of single layer of squamous epithelium. Tunica media and elastin fibres are absent. The capillary beds are the site for exchange of materials between blood and tissues.

The walls of the capillaries are guarded by semilunar valves. The blood volume in the capillaries is high but the flow of blood is slow. Mixed blood (oxygenated and deoxygenated) is present in the capillaries. The capillary bed may be flooded with blood or may be completely bypassed depending on the body conditions in a particular organ.

Veins:
Veins have thinner walls and a larger lumen and hence can be easily stretched. They carry deoxygenated blood except, the pulmonary vein. The blood pressure is low and the lumen has a wide wall which is collapsible.

Tunica media is thinner in veins than in arteries. Unidirectional flow of blood in veins is due to the presence of semilunar valves that prevents backflow of blood. Blood samples are usually taken from the veins rather than artery because of low pressure in the veins.

Question 9.
Write a short note on coronary blood vessels?
Answer:
Blood vessels that supply blood to the cardiac muscles with all nutrients and removes wastes are the coronary arteries and veins. Heart muscle is supplied by two arteries namely right and left coronary arteries.

These arteries are the first branch of the aorta. Arteries usually surround the heart in the manner of a crown, hence called coronary artery (L. Corona – crown). Right ventricle and posterior portion of left ventricle are supplied by the right coronary artery. Anterior and lateral part of the left ventricle is supplied by the left coronary arteries.

Question 10.
Compare the chambers of heart and the methods of circulation in fishes, amphibians, reptiles, crocodiles, birds and mammals?
Answer:
All vertebrates have muscular chambered heart. Fishes have two chambered heart. The heart in fishes consists of sinus venosus, an atrium, one ventricle and bulbus arteriosus or conus arteriosus.

Single circulation is seen in fishes. Amphibian have two auricles and one ventricle and no inter ventricular septum whereas reptiles except crocodiles have two auricles and one ventricle and an incomplete inter ventricular septum.

Thus mixing of oxygenated and deoxygenated blood takes place in the ventricles. This type of circulation is called incomplete double circulation. The left atrium receives oxygenated blood and the right atrium receives deoxygenated blood. Pulmonary and systemic circuits are seen in Amphibianand Reptiles.

The Crocodiles, Birds and Mammals have two auricles or atrial chambers and two ventricles, the auricles and ventricles are separated by inter auricular septum and inter ventricular septum. Hence there is complete separation of oxygenated blood from the deoxygenated blood. Pulmonary and systemic circuits are evident. This type of circulation is called complete double circulation.

Question 11.
Explain the structure of human heart?
Answer:
The structure of the heart was described by Raymond de Viessens, in 1706. Human heart is made of special type of muscle called the cardiac muscle. It is situated in the thoracic cavity and its apex portion is slightly tilted towards left. It weighs about 300g in an adult.

The size of our heart is roughly equal to a closed fist. Heart is divided into four chambers, upper two small auricles or atrium and lower two large ventricles.

The walls of the ventricles are thicker than the auricles due to the presence of papillary muscles. The heart wall is made up of three layers, the outer epicardium, middle myocardium and inner endocardium. The space present between the membranes is called pericardial space and is filled with pericardial fluid.

The two auricles are separated by inter auricular septum and the two ventricles are separated by inter ventricular septum. The separation of chambers avoids mixing of oxygenated and deoxygenated blood. The auricle communicates with the ventricle through an opening called auriculo ventricular aperture which is guarded by the auriculo ventricular valves.

The opening between the right atrium and the right ventricle is guarded by the tricuspid valve (three flaps or cusps), whereas a bicuspid (two flaps or cusps) or mitral valve guards the opening between the left atrium and left ventricle. The valves of the heart allows the blood to flow only in one direction, i.e., from the atria to the ventricles and from the ventricles to the pulmonary’ artery or the aorta. These valves prevent backward flow of blood.

The opening of right and left ventricles into the pulmonary artery and aorta are guarded by aortic and pulmonary valves and are called semilunar valves. Each semilunar valve is made of three half-moon shaped cusps. The myocardium of the ventricle is thrown into irregular muscular ridges called trabeculae comeae. The trabeculae comeae are modified into chordae tendinae. The opening and closing of the semilunar valves are achieved by the chordae tendinae.

The chordae tendinae are attached to the lower end of the heart by papillary muscles. Heart receives deoxygenated blood from various parts of the body through the inferior venacava and superior venacava which open into the right auricle. Oxygenated blood from lungs is drained into the left auricle through four pulmonary veins.

Question 12.
Explain the cardiac cycle?
Answer:
The events that occur at the beginning of heart beat and lasts until the beginning of next beat is called cardiac cycle. It lasts for 0.8 seconds. The series of events that takes place in a cardiac cycle.

PHASE 1:
Ventricular diastole- The pressure in the auricles increases than that of the ventricular pressure. AV valves are open while the semi lunar valves are closed. Blood flows from the auricles into the ventricles passively.

PHASE 2:
Atrial systole – The atria contracts while the ventricles are still relaxed. The contraction of the auricles pushes maximum volume of blood to the ventricles until they reach the end diastolic volume (EDV). EDV is related to the length of the cardiac muscle fibre. More the muscle is stretched, greater the EDV and the stroke volume.

PHASE 3:
Ventricular systole (isovolumetric contraction) – The ventricular contraction forces the AV valves to close and increases the pressure inside the ventricles. The blood is then pumped from the ventricles into the aorta without change in the size of the muscle fibre length and ventricular chamber volume (isovolumetric contraction).

PHASE 4:
Ventricular systole (ventricular ejection) – Increased ventricular pressure forces the semilunar valves to open and blood is ejected out of the ventricles without backflow of blood. This point is the end of systolic volume (ESV).

PHASE 5:
(Ventricular diastole) -The ventricles begins to relax, pressure in the arteries exceeds ventricular pressure, resulting in the closure of the semilunar valves. The heart returns to phase 1 of the cardiac cycle.

Question 13.
Explain cardiac output in man?
Answer:
The amount of blood pumped out by each ventricle per minute is called cardiac output (CO). It is a product of heart rate (HR) and stroke volume (SV). Heart rate or pulse is the number of beats per minute. Pulse pressure = systolic pressure – diastolic pressure. Stroke volume (SV) is the volume of blood pumped out by one ventricle with each beat. SV depends on ventricular contraction.

CO = HR x SV. SV represents the difference between EDV (amount of blood that collects in a ventricle during diastole) and ESV (volume of blood remaining in the ventricle after contraction). SV = EDV – ESV. According to Frank – Starling law of the heart, the critical factor controlling SV is the degree to which the cardiac muscle cells are stretched just before they contract.

The most important factor stretching cardiac muscle is the amount of blood returning to the heart and distending its ventricles, venous return.
During vigorous exercise, SV may double as a result of venous return.

Heart’s pumping action normally maintains a balance between cardiac output and venous return. Because the heart is a double pump, each side can fail independently of the other. If the left side of the heart fails, it results in pulmonary congestion and if the right side fails, it results in peripheral congestion. Frank – Starling effect protects the heart from abnormal increase in blood volume.

Question 14.
Explain the importance of blood pressure?
Answer:
Blood pressure is the pressure exerted on the surface of blood vessels by the blood. This pressure circulates the blood through arteries, veins and capillaries.

There are two types of pressure, the systolic pressure and the diastolic pressure. Systolic pressure is the pressure in the arteries as the chambers of the heart contracts. Diastolic pressure is the pressure in the arteries when the heart chambers relax.

Blood pressure is measured using a sphygmomanometer (BP apparatus). It is expressed as systolic pressure / diastolic pressure. Normal blood pressure in man is about 120/80mm Hg. Mean arterial pressure is a function of cardiac output and resistance in the arterioles. The primary reflex pathway for homeostatic control of mean arterial pressure is the baroreceptor reflex.

The baroreceptor reflex functions every morning when you get out of bed. When you are lying flat the gravitational force is evenly distributed. When you stand up, gravity causes blood to pool in the lower extremities.

The decrease in blood pressure upon standing is known as orthostatic hypotension. Orthostatic reflex normally triggers baroreceptor reflex. This results in increased cardiac output and increased peripheral resistance which together increase the mean arterial pressure.

Question 15.
Explain the recording of electrocardiogram?
Answer:
An electrocardiogram (ECG) records the electrical activity of the heart over a period of time using electrodes placed on the skin, arms, legs and chest. It records the changes in electrical potential across the heart during one cardiac cycle. The special flap of muscle which initiates the heart beat is called as sinu-auricular node or SA node in the right atrium.

It spreads as a wave of contraction in the heart. The waves of the ECG are due to depolarization and not due to contraction of the heart. This wave of depolarisation occurs before the beginning of contraction of the cardiac muscle. A normal ECG shows 3 waves designated as P wave, QRS complex and T wave.

P Wave (atrial depolarisation): It is a small upward wave and indicates the depolarisation of the atria. This is the time taken for the excitation to spread through atria from SA node. Contraction of both atria lasts for around 0.8-1.0 sec.

PQ Interval (AV node delay): It is the onset of P wave to the onset of QRS complex. This is from the start of depolarisation of the atria to the beginning of ventricular depolarisation. It is the time taken for the impulse to travel from the atria to the ventricles (0.12-0.21 sec). It is the measure of AV conduction time.

QRS Complex: (ventricular depolarisation) No separate wave for atrial depolarisation in the ECG is visible. Atrial depolarisation occurs simultaneously with the ventricular depolarisation.

The normal QRS complex lasts for 0.06-0.09 sec. QRS complex is shorter than the P wave, because depolarisation spreads through the Purkinjie fibres. Prolonged QRS wave indicates delayed conduction through the ventricle, often caused due to ventricular hypertrophy or due to a block in the branches of the bundle of His.

repolarisation. In the heart muscle, the prolonged depolarisation is due to retardation of K+ efflux and is responsible for the plateau.

The ST segment lasts for 0.09 sec. T wave (ventricular depolarisation): It represents ventricular depolarisation. The duration of the T wave is longer than QRS complex because repolarisation takes place simultaneously throughout the ventricular depolarisation.

Question 16.
Explain the regulation of cardiac activity?
Answer:
The type of heart in human is myogenic because the heart beat originates from the muscles of the heart. The nervous and endocrine systems work together with paracrine signals (metabolic activity) to influence the diameter of the arterioles and alter the blood flow.

The neuronal control is achieved through autonomic nervous system (sympathetic and parasympathetic). Sympathetic neurons release nor-epinephrine and adrenal medulla releases epinephrine.

The two hormones bind to p – adrenergic receptors and increase the heart rate. The parasympathetic neurons secrete acetylcholine that binds to muscarinic receptors and decreases the heart beat.

Vasopressin and angiotensin II, involved in the regulation of the kidneys, results in vasoconstriction while natriuretic peptide promotes vasodilation. Vagus nerve is a parasympathetic nerve that supplies the atrium especially the SA and the AV nodes.

Question 17.
What is hypertension?
Answer:
Hypertension is the most common circulatory disease. The normal blood pressure in man is 120/80 mmHg. In cases when the diastolic pressure exceeds 90 mm Hg and the systolic pressure exceeds 150 mm Hg persistently, the condition is called hypertension. Uncontrolled hypertension may damage the heart, brain and kidneys.

Question 18.
Explain the disorder of coronary heart disease?
Answer:
Coronary heart disease occurs when the arteries are lined by atheroma. The build-up of atheroma contains cholesterol, fibres, dead muscle and platelets and is termed Atherosclerosis.

The cholesterol rich atheroma forms plaques in the inner lining of the arteries making them less elastic and reduces the blood flow. Plaque grows within the artery and tends to form blood clots, forming coronary thrombus. Thrombus in a coronary artery results in heart attack.

Question 19.
Explain the disorder stroke?
Answer:
Stroke is a condition when the blood vessels in the brain bursts (Brain haemorrhage) or, when there is a block in the artery that supplies the brain, (atherosclerosis) or thrombus. The part of the brain tissue that is supplied by this damaged artery dies due to lack of oxygen (cerebral infarction).

Angina pectoris (ischemic pain in the heart muscles) is experienced during early stages of coronary heart disease. Atheroma may partially block the coronary artery and reduce the blood supply to the heart. As a result, there is tightness or choking with difficulty in breathing. This leads to angina or chest pain. Usually it lasts for a short duration of time.

Question 20.
Explain the disorder of myocardial infarction?
Answer:
The prime defect in heart failure is a decrease in cardiac muscle contractility. The Frank – Starling curve shifts downwards and towards the right such that for a given EDV, a failing heart pumps out a smaller stroke volume than a normal healthy heart. When the blood supply to the heart muscle or myocardium is remarkably reduced it leads to death of the muscle fibres.

This condition is called heart attack or myocardial infarction. The blood clot or thrombosis blocks the blood supply to the heart and weakens the muscle fibres. It is also called Ischemic heart disease due to lack of oxygen supply to the heart muscles. If this persists it leads to chest pain or angina. Prolonged angina leads to death of the heart muscle resulting in heart failure.

Question 21.
Explain the disorder of rheumatoid heart disease?
Answer:
Rheumatic fever is an autoimmune disease which occurs 2-4 weeks after throat infection usually a streptococcal infection. The antibodies developed to combat the infection cause damage to the heart. Effects include fibrous nodules on the mitral valve, fibrosis of the connective tissue and accumulation of fluid in the pericardial cavity.

Question 22.
Explain Cardio Pulmonary Resuscitation (CPR)?
Answer:
In 1956, James Elam and Peter Safar were the first to use mouth to mouth resuscitation. CPR is a life saving procedure that is done at the time of emergency conditions such as when a person’s breath or heart beat has stopped abruptly in case of drowning, electric shock or heart attack.

CPR includes rescue of breath, which is achieved by mouth to mouth breathing, to deliver oxygen to the victim’s lungs by external chest compressions which helps to circulate blood to the vital organiser.

CPR must be performed within 4 to 6 minutes after cessation of breath to prevent brain damage or death. Along with CPR, defibrillation is also done. Defibrillation me a brief electric shock is given to the heart to recover the function of the heart.

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Samacheer Kalvi 11th Bio Botany Tissue and Tissue System Text Book Back Questions and Answers

Question 1.
Refer to the given figure and select the correct statement:

(i) A, B, and C are histogen of shoot apex
(ii) A Gives rise to medullary rays
(iii) B Gives rise to cortex
(iv) C Gives rise to epidermis
(a) (i) and (ii) only
(b) (ii) and (in) only
(c) (i) and (iii) only
(d) (iii) and (iv) only
Answer:
(c) (i) and (iii) only

Question 2.
Read the following sentences and identify the correctly matched sentences.
(i) In exarch condition, the protoxylem lies outside of metaxylem.
(ii) In endarch condition, the protoxylem lie towards the centre.
(iii) In centarch condition, metaxylem lies in the middle of the protoxylem.
(iv) In mesarch condition, protoxylem lies in the middle of the metaxylem.
(a) (i), (ii) and (iii) only
(b) (ii), (iii) and (iv) only
(c) (i), (ii) and (iv) only
(d) All of these
Answer:
(c) (i), (ii) and (iv) only

Question 3.
In Gymnosperms, the activity of sieve tubes are controlled by:
(a) Nearby sieve tube members.
(b) Phloem parenchyma cells.
(c) Nucleus of companion cells.
(d) Nucleus of albuminous cells.
Answer:
(c) Nucleus of companion cells.

Question 4.
When a leaf trace extends from a vascular bundle in a dicot stem, what would be the arrangement of vascular tissues in the veins of the leaf?
(a) Xylem would be on top and the phloem on the bottom
(b) Phloem would be on top and the xylem on the bottom
(c) Xylem would encircle the phloem
(d) Phloem would encircle the xylem
Answer:
(a) Xylem would be on top and the phloem on the bottom

Question 5.
Grafting is successful in dicots but not in monocots because the dicots have:
(a) vascular bundles arranged in a ring
(b) cambium for secondary growth
(c) vessels with elements arranged end to end
(d) cork cambium
Answer:
(b) cambium for secondary growth

Question 6.
Why the cells of sclerenchyma and tracheids become dead?
Answer:
The cells of sclerenchyma and tracheids become dead because they lack protoplasm.

Question 7.
Explain sclereids with their types.
Answer:
Sclereids are dead cells, usually these are isodiametric but some are elongated too. The cell wall is very thick due to lignification. Lumen is very much reduced. The pits may simple or branched. Sclereids are mechanical in function. They give hard texture to the seed coats, endosperms etc., Sclereids are classified into the following types.

1. Branchysclereids or Stone cells: Isodiametric sclereids, with hard cell wall. It is found in bark, pith cortex, hard endosperm and fleshy portion of some fruits. eg: Pulp of Pyrus.
2. Macrosclereids: Elongated and rod shaped cells, found in the outer seed coat of leguminous plants. eg: Crotalaria and Pisum sativum.
3. Osteosclereids (Bone cells): Rod shaped with dilated ends. They occur in leaves and seed coats. eg: seed coat of Pisum and Hakea.
4. Astrosclereids: Star cells with lobes or arms diverging form a central body. They occur in petioles and leaves. eg: Tea, Nymphae and Trochodendron.
5. Trichosclereids: Hair like thin walled sclereids. Numerous small angular crystals are embedded in the wall of these sclereids, present in stems and leaves of hydrophytes. eg: Nymphaea leaf and Aerial roots of Monstera

Question 8.
What are sieve tubes? Explain.
Answer:
Sieve tubes are long tube like conducting elements in the phloem. These are formed from a series of cells called sieve tube elements. The sieve tube elements are arranged one above the other and form vertical sieve tube. The end wall contains a number of pores and it looks like a sieve. So it is called as sieve plate. The sieve elements show nacreous thickenings on their lateral walls. They may possess simple or compound sieve plates.

The function of sieve tubes are believed to be controlled by campanion cells In mature sieve tube, Nucleus is absent. It contains a lining layer of cytoplasm. A special protein (P. Protein = Phloem Protein) called slime body is seen in it. In mature sieve tubes, the pores in the sieve plate are blocked by a substance called callose (callose plug). The conduction of food material takes lace through cytoplasmic strands. Sieve tubes occur only in Angiosperms.

Question 9.
Distinguish the anatomy of dicot root from monocot root.
Answer:
The anatomy of dicot root from monocot root:

Question 10.
Distinguish the anatomy of dicot stem from monocot stem.
Answer:
The anatomy of dicot stem from monocot stem:

Samacheer Kalvi 11th Bio Botany Tissue and Tissue System Other Important Questions & Answers

I. Choose the correct answer. (1 Mark)
Question 1.
Who is the father of plant anatomy?
(a) David Muller
(b) Katherine Esau
(c) Nehemiah Grew
(d) Hofmeister
Answer:
(c) Nehemiah Grew

Question 2.
The study of internal structure and organisation of plant is called:
(a) plant taxonomy
(b) plant anatomy
(c) plant physiology
(d) plant ecology
Answer:
(b) plant anatomy

Question 3.
The book “Anatomy of seed plants” is written by:
(a) Hanstein
(b) Schmidt
(c) Nicholsen
(d) Katherine Esau
Answer:
(d) Katherine Esau

Question 4.
The term meristem is coined by:
(a) Nageli
(b) Robert
(c) Stevers
(d) Clowes
Answer:
(a) Nageli

Question 5.
Which of the statement is not correct?
(a) Meristematic cells are self perpetuating
(b) Meristematic cells are most actively dividing cells
(c) Meristematic cells have large vacuoles
(d) Meristematic cells have dense cytoplasm with prominent nucleus
Answer:
(c) Meristematic cells have large vacuoles

Question 6.
Apical cell theory is proposed by:
(a) David brown
(b) Hofmeister
(c) Land mark
(d) Clowes
Answer:
(b) Hofmeister

Question 7.
The tunica is:
(a) the peripheral zone of shoot apex, that forms cortex
(b) the inner zone of shoot apex, that forms stele
(c) the peripheral zone of shoot apex, that forms epidermis
(d) the inner zone of shoot apex, that forms cortex and stele
Answer:
(c) the peripheral zone of shoot apex, that forms epidermis

Question 8.
Which of the histogens gives rise to root cap?
(a) Plerome
(b) Periblem
(c) Dermatogen
(d) Calyptrogen
Answer:
(d) Calyptrogen

Question 9.
Quiescent centre concept was proposed by:
(a) Lindall
(b) Clowes
(c) Holstein
(d) Sanio
Answer:
(b) Clowes

Question 10.
Parenchyma cells which stores resin, tannins, calcium carbonate and calcium oxalate are termed as:
(a) critoblast
(b) chromoblasts
(c) idioblasts
(d) astroblasts
Answer:
(c) idioblasts

Question 11.
Petioles of banana is composed of:
(a) storage parenchyma
(b) stellate parenchyma
(c) angular collenchyma
(d) prosenchyma
Answer:
(b) stellate parenchyma

Question 12.
Which of the following statement is not correct?
(a) Sclerenchyma is a dead cell
(b) It lacks protoplasm
(c) The cell walls of these cells are uniformly thickened
(d) Sclerenchyma are actively dividing cells
Answer:
(d) Sclerenchyma are actively dividing cells

Question 13.
The seed coat of ground nut is made up of:
(a) stone cells
(b) osteosclereids
(c) macrosclereids
(d) parenchyma cells
Answer:
(b) osteosclereids

Question 14.
Plant fibers are modified:
(a) sclerenchyma cells
(b) collenchyma cells
(c) parenchyma cells
(d) none of the above
Answer:
(a) sclerenchyma cells

Question 15.
The term xylem was introduced by:
(a) Alexander
(b) Nageli
(c) Holstein
(d) Schemidt
Answer:
(b) Nageli

Question 16.
What type of xylem arrangement is seen in Selaginella sp?
(a) Endarch
(b) Exarch
(c) Centrarch
(d) Mesarch
Answer:
(c) Centrarch

Question 17.
In cross section, the tracheids are:
(a) hexagonal in shape
(b) rectangular in shape
(c) triangular in shape
(d) polygonal in shape
Answer:
(d) polygonal in shape

Question 18.
In grasses the guard cells in stoma are:
(a) bean shaped
(b) irregular shaped
(c) dumbbell shaped
(d) bell shaped
Answer:
(c) dumbbell shaped

Question 19.
Bulliform cells are present in:
(a) mango
(b) grasses
(c) ground nut
(d) potato
Answer:
(b) grasses

Question 20.
The sunken stomata:
(a) reduce water loss by transpiration
(b) increase water loss by transpiration
(c) increase heat loss by evaporation
(d) neither reduce nor increase water loss by transpiration
Answer:
(a) reduce water loss by transpiration

Question 21.
In Ocimum the trichomes are:
(a) non – glandular
(b) fibrous
(c) glandular
(d) none of these
Answer:
(c) glandular

Question 22.
In dicot stem, the hypodermis is generally:
(a) parenchymatous
(b) sclerenchymatous
(c) collenchymatous
(d) none of these
Answer:
(c) collenchymatous

Question 23.
Casparian strips contain thickenings of:
(a) calcium carbonate and calcium oxalate
(b) carbohydrate, protein and lignin
(c) crystal of calcium oxalate
(d) lignin, suberin and some other carbohydrates
Answer:
(d) lignin, suberin and some other carbohydrates

Question 24.
Indicate the correct statement:
(a) Albuminous cells in gymnosperms are a nucleated parenchyma cells.
(b) Albuminous cells in gymnosperms are nucleated collenchyma cells.
(c) Albuminous cells in gymnosperms are nucleated, thin walled parenchyma cells.
(d) Albuminous cells in gymnosperms are a nucleated sclerenchyma cells.
Answer:
(c) Albuminous cells in gymnosperms are nucleated, thin walled parenchyma cells.

Question 25.
Secondary phloem is derived from:
(a) apical meritesm
(b) vascular cambium
(c) primary phloem
(d) none of the above
Answer:
(b) vascular cambium

Question 26.
Which of the following statement is not correct?
(a) The outer most layer of the root is called piliferous layer.
(b) The chief function of piliferous layer is protection.
(c) Piliferous layer is made up of parenchyma cells with intracellular space.
(d) Piliferous layer is made up of parenchyma cells without intracellular space.
Answer:
(d) Piliferous layer is made up of parenchyma cells without intracellular space.

Question 27.
In beans, the metaxylem vessels are generally:
(a) polygonal in shape
(b) circular in shape
(d) rectangular in shape
(d) triangular in shape
Answer:
(a) polygonal in shape

Question 28.
Who discovered the Annular collenchyma?
(a) Clowes
(b) Sanio
(c) Nageli
(d) Duchaigne
Answer:
(d) Duchaigne

Question 29.
The main function of xylem is:
(a) to conduct the minerals to various parts of plants
(b) to conduct oxygen to various parts of plant body
(c) to conduct water and minerals from root to the other parts of the plant body
(d) to conduct stored food to various parts of plant body
Answer:
(c) to conduct water and minerals from root to the other parts of the plant body

Question 30.
In maize the vascular bundles are:
(a) scattered
(b) concentric
(c) excentric
(d) radial
Answer:
(a) scattered

Question 31.
stomata in leaves of a plant are used for:
(a) transpiration
(b) transpiration and gas exchange
(c) gas exchange
(d) none of the above
Answer:
(b) transpiration and gas exchange

Question 32.
Which of the statement is not correct?
(a) Palisade parenchyma cells are seen beneath the upper epidermis
(b) Palisade parenchyma cells contain more chloroplasts
(c) Palisade parenchyma cells are irregularly shaped
(d) The function of palisade parenchyma is photosynthesis
Answer:
(c) Palisade parenchyma cells are irregularly shaped

Question 33.
Spongy parenchyma cells are:
(a) irregularly shaped
(b) elongated cylindrical cells
(c) very lightly arranged cells
(d) with more number of chloroplasts than palisade parenchyma
Answer:
(a) irregularly shaped

Question 34.
The main function of spongy parenchyma is:
(a) photosynthesis
(b) exchange of gases
(c) exchange of minerals
(d) water transport
Answer:
(b) exchange of gases

Question 35.
All mesophyll cells in monocot leaf are nearly:
(a) isodiametric and thick walled
(b) irregular and thick walled
(c) isodiametric and thin walled
(d) irregular and thin willed
Answer:
(c) isodiametric and thin walled

Question 36.
Structurally, hydathodes are modified:
(a) cambium tissue
(b) parenchyma
(c) pith
(d) stomata
Answer:
(d) stomata

Question 37.
Hydathodes occurs in the leaves of:
(a) desert plants
(b) submerged aquatic plants
(c) floating aquatic weeds
(d) forest trees
Answer:
(b) submerged aquatic plants

Question 38.
The process of guttation is seen in:
(a) grasses
(b) dicot plants
(c) desert plants
(d) Nerium
Answer:
(a) grasses

Question 39.
Salt glands are present in:
(a) xerophytes
(b) hydrophytes
(c) halophytes
(d) merophytes
Answer:
(c) halophytes

Question 40.
The term sieve tubes is coined by:
(a) Schleiden
(b) Hanstein
(c) Tsehireh
(d) Hartig
Answer:
(d) Hartig

II. Answer the following. (2 Marks)

Question 1.
Define the tissue?
Answer:
A tissue is a group of cells that are alike in origin, structure and function. The study of tissue is called Histology.

Question 2. What are the different types of plant tissue?
Answer:
The two types of principal groups are:

1. Meristematic tissues
2. Permanent tissues.

Question 3.
Mention any, two characters of meriste – matic tissue.
Answer:
Two characters of meriste – matic tissue:

1. The meristematic cells are isodiametric and they may be, oval, spherical or polygonal in shape.
2. They have generally dense cytoplasm with prominent nucleus.

Question 4.
Mention the function of apical meristem.
Answer:
Present in apices of root and shoot. It is responsible for increase in the length of the plant, it is called as primary growth.

Question 5.
What is mean by carpus?
Answer:
It is the inner zone of shoot apex,that forms cortex and stele of shoot.

Question 6.
Explain apical cell theory?
Answer:
Apical cell theory is proposed by Nageli. The single apical cell or apical initial composes the root meristem. The apical initial is tetrahedral in shape and produces root cap from one side. The remaining three sides produce epidermis, cortex and vascular tissues. It is found in vascular cryptogams.

Question 7.
What is meant by angular collenchyma?
Answer:
It is the most common type of collenchyma with irregular arrangement and thickening at the angles where cells meet., eg: Hypodermis of Datum and Nicotiana.

Question 8.
Explain briefly Branchysciereids or Stone cells.
Answer:
Isodiametric sclereids, with hard cell wall. It is found in bark, pith cortex, hard endosperm and fleshy portion of some fruits. eg: Pulp of Pyrus.

Question 9.
What is Filiform Sclereids?
Answer:
The sclereids are present in the leaf lamina of Olea europaea. They are very much elongated fibre like and about 1mm length.

Question 10.
Distinguish between Libriform fibres and Fibre tracheids.
Answer:
Between Libriform fibres and Fibre tracheids:

Libriform fibres	Fibre tracheids
1. These fibres have slightly lignified secondary walls with simple pits. These fibres are long and narrow.	1. These are shorter than the libriform fibres with moderate secondary thickenings in the cell walls. Pits are simple or bordered.

Question 11.
What are bast fibres?
Answer:
These fibres are present in the phloem. Natural Bast fibres are strong and cellulosic. Fibres obtaining from the phloem or outer bark of jute, kenaf, flax and hemp plants. The so called pericyclic fibres are actually phloem fibres.

Question 12.
What is meant by endarch type of xylem arrangements?
Answer:
Protoxylem lies towards the .centre and meta xylem towards the periphery this condition is called Endarch. It is seen in stems.

Question 13.
What are the types of cells present in phloem?
Answer:
Phloem consists of four types of Cells:

1. Sieve elements
2. Companion cells
3. Phloem parenchyma
4. Phloem fibres.

Question 14.
Define epiblema?
Answer:
It is made up of single layer of parenchyma cells which are arranged compactly without intercellular spaces. It is devoid of epidermal pores and cuticle. Root hair is always single celled, it absorbs water and mineral salts from the soil. The another important function of piliferous layer is protection.

Question 15.
Explain bulliform cells in grasses.
Answer:
Some cells of upper epidermis (eg: Grasses) are larger and thin walled. They are called bulliform cells or motor cells. These cells are helpful for the rolling and unrolling of the leaf according to the weather change.

Question 16.
What is meant by Sunken Stomata?
Answer:
In some Xerophytic plants (eg: Cycas, Nerium), stomata is sunken beneath the abaxial leaf surface within stomatal crypts. The sunken stomata reduce water loss by transpiration.

Question 1 7.
Mention any two functions of epidermal tissue system in plants.
Answer:
Two functions of epidermal tissue system in plants:

1. This system in the shoot checks excessive loss of water due to the presence of cuticle.
2. Epidermis protects the underlying tissues.

Question 18.
Define chlorenchymo?
Answer:
Sometimes in young stem, chloroplasts develop in peripheral cortical cells, which is Called chlorenchyma.

Question 19.
What is meant by casparian strips?
Answer:
In true root endodermis, radial and inner tangential walls of endodermal cells possess thickenings of lignin, suberin and some other carbohydrates in the form of strips they are called casparian strips.

Question 20.
What are albuminous cells?
Answer:
The cytoplasmic nucleated parenchyma, is associated with the sieve cells of Gymnosperms. Albuminous cells in Conifers are analogous to companion cells of Angiosperms. It also called as strasburger cells.

Question 21.
Describe briefly radial types of vascular Bundles.
Answer:
Xylem and phloem are present on different radii alternating with each other. The bundles are separated by parenchymatous tissue. (Monocot and Dicot roots).

Question 22.
Define stele?
Answer:
All the tissues inside the endodermis comprise the stele. This includes pericycle, vascular system and pith.

Question 23.
What is meant by cambium?
Answer:
Cambium consists of brick shaped and thin walled meristematic cells. It is one to four layers in thickness. These cells are capable of forming new cells during secondary growth.

Question 24.
Define silica Cells?
Answer:
Some of the epidermal cells of the grass are filled with silica. They are called silica cells.

Question 25.
Define, hydathode?
Answer:
A hydathode is a type of epidermal pore, commonly found in higher plants. Structurally, hydathodes are modified stomata, usually located at leaf tips or margins, especially at the teeth. Hydathodes occur in the leaves of submerged aquatic plants such as ranunculus fluitans as well as in many herbaceous land plants.

III. Answer the following. (3 Marks)

Question 1.
Explain apical cell theory.
Answer:
Apical cell theory is proposed by Hofmeister (1852) and supported by Nageli (1859). A single apical cell is the structural and functional unit. This apical cell governs the growth and development of whole plant body. It is applicable in Algae, Bryophytes and in some Pteridophytes.

Question 2.
Explain histogen theory.
Answer:
Histogen theory is proposed by Hanstein (1868) and supported by Strassburgur. The shoot apex comprises three distinct zones.

1. Dermatogen: It is a outermost layer. It gives rise to epidermis.
2. Periblem: It is a middle layer. It gives rise to cortex.
3. Plerome: It is innermost layer. It gives rise to stele.

Question 3.
What is meant by quiescent centre concept?
Answer:
Quiescent centre concept was proposed by Clowes (1961) to explain root apical meristem activity. These centre is located between root cap and differentiating cells of the roots. The apparently inactive region of cells in root promeristem is called quiescent centre. It is the site of hormone synthesis and also the ultimate source of all meristematic cells of the meristem.

Question 4.
Explain the term “sclereids”.
Answer:
Sclereids are dead cells, usually these are isodiametric but some are elongated too. The cell wall is very thick due to lignification. Lumen is very much reduced. The pits may simple or branched. Sclereids are mechanical in function. They give hard texture to the seed coats, endosperms etc.

Question 5.
Explain briefly about plant fibres.
Answer:
Fibres are very much elongated sclerenchyma cells with pointed tips. Fibres are dead cells and have lignified walls with narrow lumen. They have simple pits. They provide mechanical strength and protect them from the strong wind. It is also called supporting tissues. Fibres have a great commercial value in cottage and textile industries.

Question 6.
Write briefly about xylem fibres.
Answer:
The fibres of sclerenchyma associated with the xylem are known as xylem fibres. Xylem fibres are dead cells and have lignified walls with narrow lumen. They cannot conduct water but being stronger provide mechanical strength. They are present in both primary and secondary xylem. Xylem fibres are also called libriform fibres.
The fibres are abundantly found in many plants. They occur in patches, in continuous bands and sometimes singly among other cells. Between fibres and normal tracheids, there are many transitional forms which are neither typical fibres nor typical tracheids. The transitional types are designated as fibre – tracheids. The pits of fibre – tracheids are smaller than those of vessels and typical tracheids.

Question 7.
Explain companion cells.
Answer:
The thin walled, elongated, specialized parenchyma cells, which are associated with die sieve elements, are called companion cells. These cells are living and they have cytoplasm and a prominent nucleus. They are connected to the sieve tubes through pits found in the lateral walls. Through these pits cytoplasmic connections are maintained between these elements. These cells are helpful in maintaining the pressure gradient in the sieve tubes. Usually the nuclei of the companion cells serve for the nuclei of sieve tubes as they lack them. The companion cells are present only in Angiosperms and absent in Gymnosperms and Pteridophytes. They assist the sieve tubes in the conduction of food materials.

Question 8.
Distinguish between meristematic tissue and permanent tissue.
Answer:
Between meristematic tissue and permanent tissue:

Meristematic tissue	Permanent tissue
1. Cells divide repeatedly	1. Do not divide
2. Cells are undifferentiated	2. Cells are fully differentiated
3. Cells are small and Isodiametric	3. Cells are variable in shape and size
4. Intercellular spaces are absent	4. Intercellular spaces are present
5. Vacuoles are absent	5. Vacuoles are present
6. Cell walls are thin	6. Cell walls maybe thick or thin
7. Inorganic inclusions are absent	7. Inorganic inclusions  are present

Question 9.
Write down the differences between tracheids and fibres.
Answer:
The differences between tracheids and fibres:

Tracheids	Fibres
1. Not much elongated	1. Very long cells
2. Posses oblique end walls	2. Posses tapering end walls
3. Cell walls are not as thick as fibtres	3. Cell wall are thick and lignified
4. Possess various types of thickenings	4. Possess only pitted thickenings
5. Responsible for the conduction and also mechanical support	5. Provide only mechanical support

Question 10.
Give a brief answer on subsidiary cells in plant leaves.
Answer:
Stomata are minute pores surrounded by two guard cells. The stomata occur mainly in the epidermis of leaves. In some plants addition to guard cells, specialised epidermal cells are present which are distinct from other epidermal cells. They are called Subsidiary cells. Based on the number and arrangement of subsidiary cells around the guard cells, the various types of stomata are recognised, The guard cells and subsidiary cells help in opening and closing of stomata during gaseous exchange and transpiration.

Question 11.
Explain the term trichomes.
Answer:
There are many types of epidermal outgrowths in stems. The unicellular or multicellular appendages that originate from the epidermal cells are called trichomes. Trichomes may be branched or unbranched and one or more one celled thick. They assume many shapes and sizes. They may also be glandular (eg: Rose, Ocimum) or non – glandular.

Question 12.
What do you understand about hypodermis in plant tissue system.
Answer:
One or two layers of continuous or discontinuous tissue present below the epidermis, is called hypodermis. It is protective in function. In dicot stem, hypodermis is generally collenchymatous, whereas in monocot stem, it is generally sclerenchymatous. In many plants collenchyma form the hypodermis.

Question 13.
What is meant by pith?’
Answer:
The central part of the ground tissue is known as pith or medulla. Generally this is made up of thin walled parenchyma cells with intercellular spaces. The cells in the pith generally stores starch, fatty substances, tannins, phenols, calcium oxalate crystals, etc.

Question 14.
Explain the piliferous layer as epiblema.
Answer:
The outermost layer of the root is known as piliferous layer. It consists of single row of thin – walled parenchymatous cells without any intercellular space. Epidermal pores and cuticle are absent in the piliferous layer. Root hairs that are found in the piliferous layer are always unicellular. They absorb waer and mineral salt from the soil. Root hairs are generally short lived. The main function of piliferous layer is protection of the inner tissues.

Question 15.
What is meant by stele in plant stem?
Answer:
The central part of the stem inner to the endodermis is known as stele. It consists of pericyle, vascular bundles and pith. In dicot stem, vascular bundles are arranged in a ring around the pith. This type of stele is called eustele.

Question 16.
Explain the nature of phloem in dicot stem.
Answer:
Primary phloem lies towards the periphery. It consists of protpphloem and metaphloem. Phloem consists of sieve tubes, companion cells and phloem parenchyma. Phloem fibres are absent in primary phloem. Phloem conduct organic foods material from the leaves to other parts of the plant body.

Question 17.
Explain the mesophyll layer of leaf.
Answer:
The ground tissue that is present between the upper and lower epidermis of the leaf is called mesophyll. Here, the mesophyll is not differentiated into palisade and spongy parenchyma. All the mesophyll cells are nearly isodiametric and thin walled. These cells are compactly arranged with limited intercellular spaces. They contain numerous chloroplasts.

Question 18.
Mention any three differences between stomata and hydathodes.
Answer:
Stomata:

1. Occur in epidermis of leaves, young stems.
2. Stomatal aperture is guarded by two guard cells.
3. The two guard cells are generally surrounded by subsidiary cell.

Hydathodes:

1. Occur at the tip or margin of leaves that are grown in moist shady place.
2. Aperture of hydathodes are surrounded by a ring of cuticularized cells.
3. Subsidiary cells are absent.,

Question 19.
What are halophiles? Explain briefly.
Answer:
Halophiles:

1. Plants that grow in salty environment are called Halophiles.
2. Plant growth in saline habitat developed numerous adaptations to salt stress. The secretion of ions by salt glands is the best known mechanism for regulating the salt content of plant shoots.
3. Salt glands typically are found in halophytes. (Plants that grow in saline environments)

IV. Answer in detail.

Question 1.
Explain Histogen theory, Korper Kappe Theory and Quiescent Centre Concept with diagrams.
Answer:
Histogen Theory: Histogen theory is proposed by Hanstein (1868) and supported by Strassburgur. The histogen theory as appilied to the root apical meristem speaks of four histogen in the meristem. They are respectively

1. Dermatogen: It is a outermost layer. It gives rise to root epidermis.
2. Periblem: it is a middle layer. It gives rise to cortex.
3. Plerome: It is innermost layer. It gives rise to stele.
4. Calyptrogen: it gives rise to root cap.
   

Korper Kappe Theory: Korper kappe theory is proposed by Schuepp. There are two zones in root apex – Korper and Kappe.

1. Korper zone forms the body.
2. Kappe zone forms The cap.

This theory is equivalent to tunica corpus theory of shoot apex.The two divisions are distinguished by the type of T (also called Y divisions). Korper is characterised by inverted T division and kappe by straight T divisions.

Quiescent Centre Concept: Quiescent centre concept was proposed by Clowes (1961) to explain root apical meristem activity. These centre is located between root cap and differentiating cells of the roots. The apparently inactive region of cells in root promeristem is called quiescent centre. It is the site of hormone synthesis and also the ultimate source of all meristematic cells of the meristem.

Question 2.
Describe the structure and function of different kinds of parenchyma tissues?
Answer:

Parenchyma is generally present in all organs of the plant. It forms the ground tissue in a plant. Parenchyma is a living tissue and made up of thin walled cells. The cell wall is made up of cellulose. Parenchyma cells may be oval, polyhedral, cylindrical, irregular, elongated or armed. Parenchyma tissue normally has prominent intercellular spaces. Parenchyma may store various types of materials like, water, air, ergastic substances. It is usually colourless. The turgid parenchyma cells help in giving rigidity to the plant body. Partial conduction of water is also maintained through parenchymatous cells. Occsionaliy Parenchyma cells which store resin, tannins, crystals of calcium carbonate, calcium oxalate are called idioblasts. Parenchyma is of different types and some of them are discussed as follows. Types of paranchyma:
(i) Aerenchyma: Parenchyma which contains air in its intercellular spaces. It helps in aeration and buoyancy. eg: Nymphae and Hydrilia.

(ii) Storage Parenchyma: parenchyma stores food materials. eg: Root and stem tubers.

(iii) Stellate Parenchyma: Star shaped parenchyma. eg: Petioles of Banana and Canna.

(iv) Chlorenchyma: Parenchyma cells with chlorophyll. Function is photosynthesis, eg: Mesophyll of leaves.

(v) Prosenchyma: parenchyma cells became elongated, pointed and slightly thick walled. It provides mechanical support.

Question 3.
Describe the types of tracheids with diagram.
Answer:

Types of secondary wall thickenings in tracheids and vessels:
Tracheids are dead, lignified and elongated cells with tapering ends. Its lumen is broader than that of fibres. In cross section, the tracheids are polygonal. There are different types of cell wall thickenings due to the deposition of secondary wall substances. They are annular (ring like), spiral (spring like), scalariform (ladder like) reticulate (net like) and pitted (uniformly thick except at pits). Tracheids are imperforated cells with bordered pits on their side walls. Only through this conduction takes place in Gymnosperms. They are arranged one above the other. Tracheids are chief water conducting elements in Gymnosperms and Pteridophytes. They also offer mechanical support to the plants.

Question 4.
Compare the different types of plant tissues.
Answer:
The different types of plant tissues:

Question 5.
Compare the vascular tissues of plant.
Answer:
The vascular tissues of plant:

Question 6.
Draw and label the various parts of T.S. of dicot root.
Answer:
Draw and label the various parts of T.S. of dicot root:

Question 7.
Explain in detail about the vascular bundles of monocot stem.
Answer:
1. Vascular bundles: Vascular bundles are scattered (atactostele) in the parenchyma ground tissue. Each vascular bundle is surrounded by a sheath of sclerenehymatous fibres called bundle sheath. The vascular bundles are conjoint, collateral, endarch and closed. Vascular bundles are numerous, small and closely arranged in the peripheral portion. Towards the centre, the bundles are comparatively large in size and loosely arranged. Vascular bundles are skull or oval shaped.

2. Phloem: The phloem in the monocot stem consists of sieve tubes and companion cells. Phloem parenchyma and phloem fibres are absent. It can be distinguished into an outer crushed protophloem and an inner metaphloem.

3. Xylem: Xylem vessels are arranged in the form of ‘Y’ the two metaxylem vessels at the base. In a mature bundle, the lowest protowylem disintegrates and forms a cavity known as protoxylem lacuna.

Question 8.
Draw and label the various parts of monocot stem.
Answer:
The various parts of monocot stem:

Question 9.
Explain the various parts of sunflower leaf with neat diagram.
Answer:
1. Anatomy of a Dicot Leaf – sunflower Leaf: Internal structure of dicotyledonous leaves reveal epidermis, mesophyll and vascular tissues.

2. Epidermis: This leaf is generally dorsiventral. It has upper and lower epidermis. The epidermis is usually made up of a single layer of cells that are closely packed. The cuticle on the upper epidermis is thicker than that of lower epidermis. The minute opening found on the epidermis are called stomata. Stomata are more in number on the lower epidermis than on the upper epidermis.

A stomata is surrounded by a pair of bean shaped cells are called guard cells. Each stoma internally opens into an air chamber. These guard cells contain chlotroplasts. The main function of epidermis is to give protection to the inner tissue called mesospyll. The cuticle helps to check transpiration. Stomata are used for transpiration and gas exchange.

3. Mesophyll: The entire tissue between the upper and lower epidermis is called mesophyll (GK meso = in the middle, phyllome = leaf). There are two regions in the mesophyll. They are palisade parenchyma and spongy parenchyma. Palisade parenchyma cells are seen beneath the upper epidermis. It consists of vertically elongated cylindrical cells in one or more layers. These are compactly arranged and are generally without intercellular spaces. Palisade parenchyma cells contain more chloroplasts than the spongy parenchyma cells.

The function of palisade parenchyma is photosynthesis. Spongy parenchyma lies below the palsied parenchyma. Spongy cells are irregularly shaped. These cells are very loosly arranged with numerous airspaces. As compared to palisade cells, the spongy cells contain number of chloroplasts. Spongy cells facilitate the exchange of gases with the help of air spaces. The air space that is found next to the stomata is called respiratory cavity or substomatal cavity. Å

4. Vascular tissue: Vascular tissue are present in the veins of leaf. Vascular bundles are conjoint collateral and closed. Xylem is present towards the upper epidermis, while the phloem towards the lower epidermis. Vascular bundles are surrounded by a compact layer by a parenchymatous cells called bundle sheath or border parenchyma.

Xylem consists of metaxylem and protoxylem elements. Protoxylem is present towards the upper epidermis, while the phloem consists of sieve tubes, companion cells and phloem parenchyma. Phloem fibres are absent. Xylem sonsists of vessels and xylem parenchyma. Tracheids and xylem fibres are absent.

Solution To Activity
Text Book Page No. 10
Question 1.
Cell lab: Students prepare the slide and identify the different types tissues.
Answer:
Preparing a slide of plant tissue.
Objective:

1. Using hand cutting method to make thin slice of dicot root.
2. To make slide and stain of plant sample.
3. To observe the plant sample under microscope.

Materials:

1. A young dicot root
2. Compound microscope
3. Slide
4. Cover slip
5. Eosin stain

Method:

1. Place 2 cm of young dicot root on a glass slide or plate.
2. Cut thin slices of the root through the region of maturation.
3. Stain it with Eosin.
4. Fix one or two of the sections in a slide and put a cover slip.
5. To observe the sample under a compound microscope and record the parts of the sample.

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Samacheer Kalvi 11th Bio Botany Biomolecules Text Book Back Questions and Answers

I. Multiple Choice Questions
Choose the correct answer
Question 1.
The most basic amino acid is …………… .
(a) Arginine
(b) Histidine
(c) Glycine
(d) Glutamine
Answer:
(a) Arginine

Question 2.
An example of feedback inhibition is  …………… .
(a) Cyanide action on cytochrome
(b) Sulpha drug on folic acid synthesiser bacteria
(c) Allosteric inhibition of hexokinase by glucose – 6 – phosphate
(d) The inhibition of succinic dehydrogenase by malonate
Answer:
(c) Allosteric inhibition of hexokinase by glucose – 6 – phosphate

Question 3.
Enzymes that catalyse interconversion of optical, geometrical or positional isomers are …………… .
(a) Ligases
(b) Lyases
(c) Hydrolases
(d) Isomerases
Answer:
(d) Isomerases

Question 4.
Proteins perform many physiological functions. For example some functions as enzymes. One of the following represents an additional function that some proteins discharge …………… .
(a) Antibiotics
(b) Pigment conferring colour to skin
(c) Pigments making colours of flowers
(d) Hormones
Answer:
(d) Hormones

Question 5.
Given below is the diagrammatic representation of one of the categories of small molecular weight organic compounds in the living tissues. Identify the category shown & one blank component “X” in it …………… .

Answer:
(a) Nucleoside
(b) Uracil.

Question 6.
Distinguish between nitrogenous base and a base found in inorganic chemistry.
Answer:
Nitrogenous Base:

1. Nitrogenous bases are organic molecules containing the element nitrogen & acts as a base in chemical reaction.
2. e.g. Adenine, Thymine

Base:

1. Bases are the substance that release hydroxide (OH^– ) ions in aqueous solution.
2. e.g. NaOH and Ca(OH)₂

Question 7.
What are the factors affecting the rate of enzyme reaction?
Answer:
(a) Temperature: Heating increases molecular motion. Thus the molecules of the substrate and enzyme move more quickly resulting in a greater probability of occurrence of the reaction. The temperature that promotes maximum activity is referred to as optimum temperature.

(b) pH: The optimum pH is that at which the maximum rate of reaction occurs. Thus the pH change leads to an alteration of enzyme shape, including the active site. If extremes of pH are encountered by an enzyme, then it will be denatured.

(c) Substrate Concentration: For a given enzyme concentration, the rate of an enzyme reaction increases with increasing substrate concentration.

(d) Enzyme Concentration: The rate of reaction is directly proportional to the enzyme concentration.

The Michaelis – Menton Constant (Km) and Its Significance:
When the initial rate of reaction of an enzyme is measured over a range of substrate concentrations (with a fixed amount of enzyme) and the results plotted on a graph. With increasing substrate concentration, the velocity increases – rapidly at lower substrate concentration. However the rate increases progressively, above a certain concentration of the substrate the curve flattened out. No further increase in rate occurs. This shows that the enzyme is working at maximum velocity at this point. On the graph, this point of maximum velocity is shown as V_Max.

Question 8.
Briefly outline the classification of enzymes.
Answer:
Enzymes are classified into six groups based on their mode of action.

Question 9.
Write the characteristic feature of DNA.
Answer:
The characteristic feature of DNA.

1. If one strand runs in the 5′ – 3′ direction, the other runs in 3′ – 5′ direction and thus are antiparallel (they run in opposite direction). The 5′ end has the phosphate group and 3’end has the OH group.
2. The angle at which the two sugars protrude from the base pairs is about 120°, for the narrow angle and 240° for the wide angle. The narrow angle between the sugars generates a minor groove and the large angle on the other edge generates major groove.
3. Each base is 0.34 nm apart and a complete turn of the helix comprises 3.4 nm or 10 base pairs per turn in the predominant B form of DNA.
4. DNA helical structure has a diameter of 20 Å and a pitch of about 3 Å. X – ray crystal study of DNA takes a stack of about 10 bp to go completely around the helix (360°).
5. Thermodynamic stability of the helix and specificity of base pairing includes
   • (a) The hydrogen bonds between the complementary bases of the double helix
   • (b) stacking interaction between bases tend to stack about each other perpendicular to the direction of helical axis. Electron cloud interactions (\({ \Pi -{ \Pi } }\)) between the bases in the helical stacks contribute to the stability of the double helix.
6. The phosphodiester linkages gives an inherent polarity to the DNA helix. They form strong covalent bonds, gives the strength and stability to the polynucleotide chain.
7. Plectonemic coiling – the two strands of the DNA are wrapped around each other in a helix, making it impossible to simply move them apart without breaking the entire structure. Whereas in paranemic coiling the two strands simply lie alongside one another, making them easier to pull apart.
8. Based on the helix and the distance between each turns, the DNA is of three forms – A DNA, B DNA and Z DNA.

Question 10.
Explain the structure and function of different types of RNA.
Answer:
1. mRNA (messenger RNA): Single stranded, carries a copy of instructions for assembling amino acids into proteins. It is very unstable and comprises 5% of total RNA polymer. Prokaryotic mRNA (Polycistronic) carry coding sequences for many polypeptides. Eukaryotic mRNA (Monocistronic) contains information for only one polypeptide.

2. tRNA (transfer RNA): Translates the code from mRNA and transfers amino acids to the ribosome to build proteins. It is highly folded into an elaborate 3D structure and comprises about 15% of total RNA. It is also called as soluble RNA.

3. rRNA (ribosomal RNA): Single stranded, metabolically stable, makeup the two subunits of ribosomes. It constitutes 80% of the total RNA. It is a polymer with varied length from 120 – 3000 nucleotides and gives ribosomes their shape. Genes for rRNA are highly conserved and employed for phylogenetic studies.

Entrance Examination Questions Solved
Choose the correct answer:
Question 1.
Who invented electron microscope? (2010 AIIMS, 2008 JIPMER)
(a) Janssen
(b) Edison
(c) Knoll and Ruska
(d) Landsteiner
Answer:
(c) Knoll and Ruska

Question 2.
Specific proteins responsible for the flow of materials and information into the cellare called …………… . (2009 AIIMS)
(a) Membrane receptors
(b) carrier proteins
(c) integral proteins
(d) none of these
Answer:
(b) carrier proteins

Question 3.
Omnis – cellula – e – cellula was given by …………… . (2007 AIIMS)
(a) Virchow
(b) Hooke
(c) Leeuwenhoek
(d) Robert Brown
Answer:
(a) Virchow

Question 4.
Which of the following is responsible for the mechanical support, protein synthesis and enzyme transport? (2007 AIIMS)
(a) cell membrane
(b) mitochondria
(c) dictyosomes
(d) endoplasmic reticulum
Answer:
(d) endoplasmic reticulum

Question 5.
Genes present in the cytoplasm of eukaryotic cells are found in …………… . (2006 AIIMS)
(a) mitochondria and inherited via egg cytoplasm
(b) lysosomes and peroxisomes
(c) Golgi bodies and smooth endoplasmic reticulum
(d) Plastids inherited via male gametes
Answer:
(a) mitochondria and inherited via egg cytoplasm

Question 6.
In which one the following would you expect to find glyoxysomes? (2005 AIIMS)
(a) Endosperm of wheat
(b) Endosperm of castor
(c) Palisade cells in leaf
(d) Root hairs
Answer:
(b) Endosperm of castor

Question 7.
A quantosome is present in …………… . (JIPMER 2012)
(a) Mitochondria
(b) Chloroplast
(c) Golgi bodies
(d) ER
Answer:
(b) Chloroplast

Question 8.
In mitochondria the enzyme cytochrome oxidase is present in …………… . (2012 JIPMER)
(a) Outer mitochondrial membrane
(b) inner mitochondrial membrane
(c) Stroma
(d) Grana
Answer:
(b) inner mitochondrial membrane

Question 9.
Which organelle is present in higher number in secretory cell? (2008 JIPMER)
(a) Mitochondria
(b) Chloroplast
(c) Nucleus
(d) Dictyosomes
Answer:
(d) Dictyosomes

Question 10.
Major site for the synthesis of lipids …………… . (2013 NEET)
(a) Rough ER
(b) smooth ER
(c) Centriole
(d) Lysosome
Answer:
(b) smooth ER

Question 11.
Golgi complex plays a major role in …………… . (2013 NEET)
(a) post translational modification of proteins and glycosidation of lipids
(b) translation of proteins
(c) Transcription of proteins
(d) Synthesis of lipid
Answer:
(a) post translational modification of proteins and glycosidation of lipids

Question 12.
Main arena of various types of activities of a cell is …………… . (2010 AIPMT)
(a) Nucleus
(b) Mitochondria
(c) Cytoplasm
(d) Chloroplast
Answer:
(c) Cytoplasm

Question 13.
The thylakoids in chloroplast are arranged in …………… . (2005 JIPMER)
(a) regular rings
(b) linear array
(c) diagonal direction
(d) stacked discs
Answer:
(d) stacked discs

Question 14.
Sequences of which of the following is used to know the phylogeny rRNA? (20022JIPMER)
(a) mRNA
(b) rRNA
(c) tRNA
(d) Hn RNA
Answer:
(b) rRNA

Question 15.
Structures between two adjacent cells which is an effective transport pathway? (2010 AIPMT)
(a) Plasmodesmata
(b) Middle lamella
(c) Secondary wall layer
(d) Primary wall layer
Answer:
(a) Plasmodesmata

Question 16.
In active transport carrier proteins are used, which use energy in the form of ATP to …………… .
(a) transport molecules against concentration gradient of cell wall
(b) transport molecules along concentration gradient of cell membrane
(c) transport molecules against concentration gradient of cell membrane
(d) transport molecules along concentration gradient of cell wall
Answer:
(c) transport molecules against concentration gradient of cell membrane

Question 17.
The main organelle involved in modification and routing of newly synthesised protein to their destinations is …………… . (AIPMT 2005)
(a) Mitochondria
(b) Glyoxysomes
(c) Spherosomes
(d) Endoplasmic reticulum
Answer:
(d) Endoplasmic reticulum

Question 18.
Algae have cell wall made up of …………… . (AIPMT 2010)
(a) Cellulose, galactans and mannans
(b) Cellulose, chitin and glucan
(c) Cellulose, Mannan and peptidoglycan
Answer:
(a) Cellulose, galactans and mannans

Samacheer Kalvi 11th Bio Botany Biomolecules Additional Questions and Answers

Question 1.
The percentage of water in the total cellular mass is …………… .
(a) 50%
(b) 60%
(c) 70%
(d) 80%
Answer:
(c) 70%

Question 2.
The metabolites which does not show any direct function in growth is called …………… metabolite.
(a) Primary
(b) Secondary
(c) Tertiary
(d) Quartemary
Answer:
(b) Secondary

Question 3.
Molecular formula for carbohydrates is …………… .
(a) (CH₂O)₂
(b) (CH₆O)
(C) (C₂H₂O)_n
(d) (CH₆O)_n
Answer:
(a) (CH₂O)₂

Question 4.
Number of carbon molecule in glucose is …………… .
(a) 4
(b) 6
(c) 8
(d) 12
Answer:
(b) 6

Question 5.
Number of sugar units in oligo saccharides are …………… .
(a) 6 to 10
(b) 1 to 10
(c) 2 to 8
(d) 2 to 10
Answer:
(d) 2 to 10

Question 6.
Which of the following is a trisaccharide?
(a) Maltose
(b) Stachyose
(c) Ramnose
(d) Aldose
Answer:
(c) Ramnose

Question 7.
…………… are also called as Glycan.
(a) Monosaccharides
(b) Disaccharides
(c) Polysaccharides
(d) Multisaccharides
Answer:
(c) Polysaccharides

Question 8.
Sucrose is a combination of …………… and fructose.
(a) α – glucose
(b) β – glucose
(c) Ketoses
(d) Maltose
Answer:
(a) α – glucose

Question 9.
…………… is also called as animal starch.
(a) Amylose
(b) Glycogen
(c) Glucose
(d) Glycerol
Answer:
(b) Glycogen

Question 10.
…………… reagent is used in starch test.
(a) Potassium permanganate
(b) Potassium iodide
(c) Calcium chloride
(d) Calcium iodide
Answer:
(b) Potassium iodide

Question 11.
Glycogen is not seen in …………… cells.
(a) liver
(b) skeletal
(c) muscle
(d) brain
Answer:
(d) Brain

Question 12.
Benedicts solution is nothing but …………… .
(a) Copper II sulphate
(b) Cuprous sulphate
(c) Cupric sulphate
(d) Copper I sulphate
Answer:
(a) Copper II sulphate

Question 13.
…………… is not a reducing sugar.
(a) Glucose
(b) Fructose
(c) Sucrose
(d) Ketose
Answer:
(c) Sucrose

Question 14.
…………… form the exoskeleton of insects & arthropods.
(a) N – acetyl glucosamine
(b) N – butyl glucosamine
(c) N – phenyl glucosamine
(d) N – methyl glucosamine
Answer:
(a) N – acetyl glucosamine

Question 15.
Number of fatty acids in triglyceride is …………… .
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(c) 3

Question 16.
The major structural component of cell membrane is …………… .
(a) glucolipids
(b) phospholipids
(c) proteolipids
(d) triglycerides
Answer:
(b) phospholipids

Question 17.
There are …………… different amino acids existing naturally.
(a) about 20
(b) about 10
(c) about 25
(d) about 22
Answer:
(a) about 20

Question 18.
A zwitterion also called as …………… ion.
(a) dipolar
(b) monopolar
(c) tripolar
(d) nonpolar
Answer:
(a) dipolar

Question 19.
…………… test is used as an indicator of the presence of protein.
(a) Biuret test
(b) Iodine test
(c) Benedict’s test
(d) Starch test
Answer:
(a) Biuret test

Question 20.
The competitive inhibitor is …………… for succinic dehydrogenase.
(a) malonate
(b) succinate
(c) oxalate
(d) citrate
Answer:
(a) malonate

Question 21.
…………… is the abundant protein in whole biosphere.
(a) RUBP
(b) NAD⁺
(c) NADPH
(d) RUBISCO
Answer:
(d) RUBISCO

Question 22.
…………… is an active enzyme with its non – protein component.
(a) Apoenzyme
(b) Holoenzyme
(c) Coenzymes
(d) Enzymes
Answer:
(b) Holoenzyme

Question 23.
Flavin adenine dinucleotide contains …………… which helps to accept hydrogen.
(a) ascolac acid
(b) cyanocobalamin
(c) riboflavin
(d) keratinine
Answer:
(c) riboflavin

Question 24.
…………… is a catalytic RNA.
(a) mRNA
(b) Ribozyme
(c) Ribonuclease
(d) rRNA
Answer:
(b) Ribozyme

Question 25.
…………… protects the end of the chromosomes from damage.
(a) Satellite
(b) Kinetochore
(c) Primary constriction
(d) Telomere
Answer:
(d) Telomere

Question 26.
Which is not a pyrimidine base?
(a) Cytosine
(b) Uracil
(c) Guanine
(d) Thymine
Answer:
(c) Guanine

Question 27.
Which type of DNA was described by Watson & Crick?
(a) Z – DNA
(b) α – DNA
(c) B – DNA
(d) A – DNA
Answer:
(c) B – DNA

Question 28.
According to Chargaff’s rule, the hydrogen bonding between Adenine and Thymine is …………… .
(a) 2
(b) 3
(c) 4
(d) Nil
Answer:
(a) 2

Question 29.
The first clear crystallographic evidence for helical structure of DNA was produced by …………… .
(a) Maurice Wilkins
(b) Rosalind Franklin
(c) Francis Crick
(d) Chargaff
Answer:
(b) Rosalind Franklin

Question 30.
According to Cargaff’s rule, A : T = G : C = …………… .
(a) 0
(b) 1
(c) >1
(d) <1
Answer:
(b) 1

Question 31.
A complete turn of the helix comprises …………… .
(a) 34 nm
(b) 3.4 nm
(c) 20 nm
(d) 2nm
Answer:
(b) 3.4 nm

Question 32.
Diameter of DNA helix is …………… .
(a) 34 Å
(b) 20 nm
(c) 34 nm
(d) 20 Å
Answer:
(d) 20 Å

Question 33.
RNA is …………… .
(a) Single stranded and stable
(b) Single stranded and unstable
(c) Double stranded and stable
(d) Double stranded and unstable
Answer:
(b) Single stranded and unstable

Question 34.
rRNA constitutes …………… of total RNA.
(a) 20%
(b) 70%
(c) 80%
(d) 15%
Answer:
(c) 80%

Question 35.
Shape to the ribosomes is provided by …………… .
(a) rRNA
(b) tRNA
(c) mRNA
(d) DNA
Answer:
(a) rRNA

Question 36.
Which RNA is also called as soluble RNA?
(a) rRNA
(b) tRNA
(c) mRNA
(d) ssRNA
Answer:
(b) tRNA

Question 37.
Which is the left – handed DNA?
(a) B – DNA
(b) A – DNA
(c) Z – DNA
(d) dsDNA
Answer:
(c) Z – DNA

Question 38.
Which of the following does not contain cell wall?
(a) Fungi
(b) Bacteria
(c) Mycoplasma
(d) Algae
Answer:
(c) Mycoplasma

Question 39.
The amino acid which is both an acid and a base is called …………… .
(a) Amphibolic
(b) Amphoteric
(c) Amphipathetic
(d) Anabolic
Answer:
(b) Amphoteric

Question 40.
…………… leads to the loss of 3D structure of protein.
(a) Annealing
(b) Extension
(c) Denaturation
(d) Polymerisation
Answer:
(c) Denaturation

Question 41.
Which of the following polysaccharides is used as solidifying agent in culture medium?
(a) Inulin
(b) Heparin
(c) Agar
(d) Keratan sulphate
Answer:
(c) Agar

Question 42.
Which is an anticoagulant?
(a) Inulin
(b) Heparin
(c) Agar
(d) Keratan sulphate
Answer:
(b) Heparin

Question 43.
Insulin is a polymer of …………… .
(a) sucrose
(b) fructose
(c) glucose
(d) maltose
Answer:
(b) fructose

II. Very Short Answer Type Questions (2 Marks)

Question 1.
Define cell pool and mention its constituents.
Answer:
The cell components are made of collection of molecules called as cellular pool, which consists of both inorganic and organic compounds.

Question 2.
Draw the molecular structure of water.
Answer:
the molecular structure of water:

Question 3.
Point out the percentage of water in human cell & a plant cell.
Answer:
Water makes upto 70% of human cell and upto 95% of mass of a plant cell.

Question 4.
What are metabolites?
Answer:
Metabolites are the organic compounds synthesized by plants, fungi and various microbes. They are the intermediates & products of metabolism.

Question 5.
Write the molecular formula for carbohydrates?
Answer:
(CH₂O)_n

Question 6.
Give an example for simple sugar with its formula.
Answer:
Glucose – C₆H₁₂O₆

Question 7.
Which type of sugar does sucrose belongs to? Write its monomer units.
Answer:
Sucrose is a disaccharides composed of α – glucose & fructose.

Question 8.
Classify polysaccharides based on function.
Answer:
Depending on the function, polysaccharides are of two types:

1. storage polysaccharide and
2. structural polysaccharide.

Question 9.
What are Glycans?
Answer:
Polysaccharides are also called as Glycans. They are made of hundreds of monosaccharide units.

Question 10.
Which is a common storage polysaccharide? Mention its monomer units.
Answer:
Starch is a storage polysaccharide made up of repeated units of amylose and amylopectin.

Question 11.
Which is an animal starch? Where can we see it in our body?
Answer:
Glycogen. It is found in liver cells & skeletal muscles.

Question 12.
Why oil does not get mixed if added with water?
Answer:
Oil is a lipid. Lipids are long hydrocarbon chains that are non-polar & thus hydrophobic, which avoids the oil to dissolve in water.

Question 13.
How saturated fatty acids differ from unsaturated fatty acids?
Answer:
Saturated factty acids have the hydrocarbon chain with single bond, whereas in unsaturated fatty acids the hydrocarbon chain will have double bonds.

Question 14.
How waxes are formed?
Answer:
Waxes are esters formed between a long chain alcohol and saturated fatty acids.

Question 15.
Why amino acids are amphoteric?
Answer:
The amino acid is both an acid and a base and is called amphoteric.

Question 16.
Name the various groups attached to the 4 valencies of carbon in an amino acid.
Answer:
The 4 valencies of carbon in an amino acid:

1. (NH₂)
   
2. an acidic carboxylic group (COOH) and
   
3. a hydrogen atom (H)
   
4. and side chain or variable R group.

Question 17.
Where the peptide bond is formed?
Answer:
A peptide bond is formed when the amino group of one amino acid reacts with carbonyl group of another amino acid.

Question 18.
Which was the first sequenced protein? Who had done it?
Answer:
First protein is insulin and it was sequenced by Fred Sanger.

Question 19.
Why proteins undergo conformational changes after its synthesis?
Answer:
After synthesis, the protein attains conformational change into a specific 3D form for proper functioning.

Question 20.
Mention the levels of protein organisation based on folding.
Answer:
According to the mode of folding, four levels of protein organisation have been recognised namely primary, secondary, tertiary and quaternary.

Question 21.
Define enzymes.
Answer:
Enzymes are globular proteins that catalyse the thousands of metabolic reactions taking place within cells and organism.

Question 22.
Name any four factors that affect enzyme reactions.
Answer:
Four factors that affect enzyme reactions:

1. pH
2. temperature
3. enzyme concentration and
4. substrate concentration.

Question 23.
What are inhibitors? Mention its types.
Answer:
Certain substances present in the cells may react with the enzyme and lower the rate of reaction. These substances are called inhibitors. It is of two types:

1. Competitive and
2. Non – competitive.

Question 24.
Differentiate Apoenzyme from Holoenzyme.
Answer:
Differ Apoenzyme from Holoenzyme:

Apoenzyme	Holoenzyme
1. Active enzyme with its non – protein component	1. Inactive enzyme without its non – protein component

Question 25.
What are Prosthetic groups? Give example.
Answer:
Prosthetic groups are organic molecules that assist in catalytic function of an enzyme. Example: Flavin adenine dinucleotide (FAD).

Question 26.
Draw a diagram showing the various components of enzymes.
Answer:
Catalytic site, Cofactor and Holoenzyme:

Question 27.
Write a note on Ribozyme.
Answer:
Ribozyme – Non – Protein Enzyme. A Ribozyme, also called as catalytic RNA; is a ribonucleic acid that acts as enzyme. It is found in ribosomes.

Question 28.
Give an example for following enzyme groups.
Answer:
An example for following enzyme groups:

1. Transferase – Ex: Transaminase
2. Isomerase – Ex: Isomerase
3. Oxidoreductase – Ex: Dehydrogenase
4. Lyase – Ex: Decarboxylase

Question 29.
Write the composition of DNA & RNA.
Answer:
Nitrogen base, pentose sugar and phosphate.

Question 30.
What is a nucleoside?
Answer:
A purine or a pyrimidine and a ribose or deoxyribose sugar is called nucleoside. A nitrogenous base is linked to pentose sugar through n-glycosidic linkage and forms a nucleoside.

Question 31.
What is a nucleotide?
Answer:
When a phosphate group is attached to a nucleoside it is called a nucleotide.

Question 32.
Name the two types of Purines and Pyrimidines.
Answer:
The two types of Purines and Pyrimidines:

1. Purines: Adenine and guanine
2. Pyrimidines: Cytosine and thymine (Uracil)

Question 33.
How DNA differs from RNA?
Answer:
DNA has thymine base, whereas RNA has uracil base. DNA has deoxyribose sugar, whereas RNA has ribose sugar.

Question 34.
Draw a simple diagram showing basic components of DNA.
Answer:
Deoxyribose sugar:

Question 35.
Which is the secondary structure of DNA? Who discovered it?
Answer:
B – DNA is the secondary structure of DNA. Watson & Crick discovered B – DNA.

Question 36.
State Chargaff’s rule.
Answer:
Chargaff’s Rule:
A = T; G = C
A + G = T + C,
A : T = G : C = 1.

Question 37.
Name the three forms of DNA.
Answer:
The three forms of DNA:

1. A – DNA
2. B – DNA and
3. Z – DNA.

Question 38.
Which is the soluble forms of RNA. Write its percentage composition of total RNA.
Answer:
tRNA is the soluble RNA which is about 15% of total RNA.

Question 39.
Name the types of RNA?
Answer:
The types of RNA:

1. mRNA
2. tRNA and
3. rRNA.

Question 40.
Draw the structure of transfer RNA.
Answer:
Transfer RNA (tRNA):

III. Short Answer Type Questions (3 Marks)

Question 1.
Distinguish between Macronutrients & Micronutrients.
Answer:
Macronutrients:

• Nutrients required in larger quantities for plant growth are called Macronutrients.
• e.g. Potassium and Calcium

Micronutrients:

• Nutrients required in trace amount for plant growth are called Micronutrients
• e.g. Zinc and Bora

Question 2.
Tabulate the various cellular components with their percentage.
Answer:
The various cellular components with their percentage:

Component	% of the total cellular mass
1. Water	1. 70
2. Proteins	2. 15
3. Carbohydrates	3. 3
4. Lipids	4. 2
5. Nucleic acids	5. 6
6. Ions	6. 4

Question 3.
List out the properties of Water.
Answer:
Properties of Water:

1. Adhesion and cohesion property
2. High latent heat of vaporisation
3. High melting and boiling point
4. Universal solvent
5. Specific heat capacity

Question 4.
How lattice formation occurs in water molecule?
Answer:
Two electro negative atoms of oxygen share a hydrogen bonds of two water molecule. Thus, they can stick together by cohesion and results in lattice formation.

Question 5.
Distinguish between Primary metabolite & Secondary metabolite.
Answer:
Between Primary metabolite & Secondary metabolite:

• Primary metabolites are those that are required for the basic metabolic processes like photosynthesis, respiration, etc Example: Lipase, a protein.
• Secondary metabolites does not show any direct function in growth and development of organisms. Example: Ricin, gums.

Question 6.
Define Polymerization.
Answer:
Polymerization, is a process in which repeating subunits termed monomers are bound into chains of different lengths. These chains of monomers are called polymers.

Question 7.
Explain the bond formation in sucrose molecule.
Answer:
Sucrose is formed from a molecule of α – glucose and a molecule of fructose. This is a condensation reaction releasing water. The bond formed between the glucose and fructose molecule by removal of water is called glycosidic bond. This is another example of strong, covalent bond.

Question 8.
How will you identify the presence of starch in a food sample.
Answer:
The presence of starch is identified by adding a solution of iodine in potassium iodide. Iodine molecules fit nearly into the starch helix, creating a blue – black colour.

Question 9.
Write a note on steroids.
Answer:
Steroids are complex compounds commonly found in cell membrane and animal hormones. e.g. Cholesterol which reinforces the structure of the cell membrane in animal cells and in an unusual group of cell wall deficient bacteria – Mycoplasma.

Question 10.
Draw the structure of basic amino acid.
Answer:
The structure of basic amino acid:

Question 11.
What is a Zwitterion? or What is an isoelectric point?
Answer:
A zwitterion also called as dipolar ion, is a molecule with two or more functional groups, of which at least one has a positive and other has a negative electrical charge and the net charge of the entire molecule is zero. The pH at which this happens is known as the isoelectric point.

Question 12.
Write briefly about protein denaturation.
Answer:
Denaturation is the loss of 3D structure of protein. Exposure to heat causes atoms to vibrate violently, and this disrupts the hydrogen and ionic bonds. Under these conditions, protein molecules become elongated, disorganised strands. Agents such as soap, detergents, acid, alcohol and some disinfectants disrupt the interchain bond and cause the molecule to be non – functional.

Question 13.
Why do some people have curly hair?
Answer:
Human hair is made of protein. The more the distance between the sulphur atoms, the more the proteins bend; the more the hair curls.

Question 14.
Write a note on RUBISCO.
Answer:
Ribulose biphosphate carboxylase oxygenase (RUBISCO) is an enzyme that catalyses the reaction between CO₂ and the CO₂ acceptor molecule in photosynthesis. It is the most abundant protein in the whole biosphere.

Question 15.
Differentiate Anabolic reaction and Catabolic reaction.
Answer:
Anabolic reaction:

• Anabolic reaction involves the building up of organic molecules.
• Ex: Synthesis of protein from amino acids.

Catabolic reaction:

• Catabolic reaction involves the breaking down of larger molecules.
• Ex: Breaking down of sugar in respiration.

Question 16.
What are Allosteric inhibitors?
Answer:
Compounds which modify enzyme activity by causing a reversible change in the structure of the enzyme active site. This in turn affects the ability of the substrate to bind to the enzyme. Such compounds are called allosteric inhibitors, e.g. The enzyme hexokinase which catalysis glucose to glucose – 6 phosphate in glycolysis is inhibited by glucose – 6 phosphate. This is an example for feedback allosteric inhibitor.

Question 17.
Explain in brief about End – product inhibitor. (Negative Feedback Inhibition)
Answer:
When the end product of a metabolic pathway begins to accumulate, it may act as an allosteric inhibitor of the enzyme controlling the first step of the pathway. Thus the product starts to switch off its own production as it builds up. The process is self – regulatory. As the product is used up, its production is switched on once again. This is called end – product inhibition.

Question 18.
Draw the structure of Purine & Pyrimidine.
Answer:
The structure of Pyrimidine & Purine:

Question 19.
Why the sugar in DNA is a deoxyribose?
Answer:
The sugar in DNA molecule is called 2’ – deoxyribose because there is no hydroxyl group at 2’ position.

Question 20.
How dinucleotide & polynucleotides are formed?
Answer:
Two nucleotides join to form dinucleotide that are linked through 3′ – 5′ phosphodiester linkage by condensation between phosphate groups of one with sugar of other. This is repeated many times to make polynucleotide.

Question 21.
Compare Plectonemic & Paranemic Coiling.
Answer:
Plectonemic coiling – the two strands of the DNA are wrapped around each other in a helix, making it impossible to simply move them apart without breaking the entire structure. Whereas in Paranemic coiling the two strands simply lie alongside one another, making them easier to pull apart.

Question 22.
Differentiate between Polycistronic & Monocistronic mRNA.
Answer:
Between Polycistronic & Monocistronic mRNA:

Polycistronic mRNA	Monocistronic mRNA
1. Polycistronic mRNA carry coding sequences for many Polypeptides	1. Monocistronic mRNA carry coding sequences for only one Polypeptide
2. Prokaryotic mRNA are polycistronic	2. Eukaryotic mRNA are monocistronic

Question 23.
What are Proteins?
Answer:
Proteins are polymers of 20 different amino acids, each of which has a distinct side chain with specific chemical properties. Each protein has a unique amino acid sequence which determines its 3D structure.

Question 24.
Herbivores can digest cellulose rich food, Why can’t human beings?
Answer:
Human cannot digest cellulose but herbivores can digest them with the help of bacteria present in the gut which produces enzymes cellulase. This is an example of mutualism.

Question 25.
How will you identify the presence of protein in food samples?
Answer:
The biuret test is used as an indicator of the presence of protein because it gives a purple colour in the presence of peptide bonds (-C- N-). To a protein solution an equal quantity of sodium hydroxide solution is added and mixed. Then a few drops of 0.5% copper (II) sulphate is added with gentle mixing. A distinct purple colour develops without heating.

Question 26.
Write a note on peptide bonds between amino acids.
Answer:
The amino group of one amino acid reacts with carboxyl group of other amino acid, forming a peptide bond. Two amino acids can react together with the loss of water to form a dipeptide. Long strings of amino acids linked by peptide bonds are called polypeptides. In 1953, Fred Sanger first sequenced the Insulin protein.

Question 27.
Which was the first alkaloid discovered? Mentions its uses.
Answer:
Morphine is the first alkaloid to be found. It comes from the plant Opium poppy (Papaver somniferum). It is used as a pain reliever in patients with severe pain levels and cough suppressant.

IV. Long Answer Type Questions (5 Marks)

Question 1.
How will you identify the presence of glucose in a given food sample?
Answer:
Aldoses and ketoses are reducing sugars. This means that, when heated with an alkaline solution of copper (II) sulphate (a blue solution called Benedict’s solution), the aldehyde or ketone group reduces Cu²⁺ ions to Cu⁺ ions forming brick red precipitate of copper (I) oxide. In the process, the aldehyde or ketone group is oxidised to a carboxyl group (-COOH).

This reaction is used as test for reducing sugar and is known as Benedict’s test. The results of Benedict’s test depends on concentration of the sugar. If there is no reducing sugar it remains blue. Sucrose is not a reducing sugar The greater the concentration of reducing sugar, the more is the precipitate formed and greater is the colour change.

Question 2.
Write a note on various levels of protein organisation.
Answer:
The primary structure is linear arrangement of amino acids in a polypeptide chain. Secondary structure arises when various functional groups are exposed on outer surface of the molecular interaction by forming hydrogen bonds. This causes the amino acid chain to twist into coiled configuration called α – helix or to fold into a flat β – pleated sheets.

Tertiary protein structure arises when the secondary level proteins fold into globular structure called domains. Quaternary protein structure may be assumed by some complex proteins in which more than one polypeptide forms a large multiunit protein. The individual polypeptide chains of the protein are called subunits and the active protein itself is called a multimer.

Question 3.
Enumerate the properties of Enzyme.
Answer:
The properties of Enzyme:

• Enzymes are globular proteins.
• They act as catalysts and effective even in small quantity.
• They remain unchanged at the end of the reaction.
• They are highly specific.
• They have an active site where the reaction takes place.
• Enzymes lower activation energy of the reaction they catalyse.

Question 4.
Draw a Flow Chart depicting the Carbohydrate Classification
Answer:
Flow Chart depicting the Carbohydrate Classification:

Question 5.
Explain the various types of chemical bonding in proteins.
Answer:
1. Hydrogen Bond: It is formed between some hydrogen atoms of oxygen and nitrogen in polypeptide chain. The hydrogen atoms have a small positive charge and oxygen and nitrogen have small negative charge. Opposite charges attract to form hydrogen bonds. Though these bonds are weak, large number of them maintains the molecule in 3D shape.

2. Ionic Bond: It is formed between any charged groups that are not joined together by peptide bond. It is stronger than hydrogen bond and can be broken by changes in pH and temperature.

3. Disulfide Bond: Some amino acids like cysteine and methionine have sulphur. These form disulphide bridge between sulphur atoms and amino acids.

4. Hydrophobic Bond: This bond helps some protein to maintain structure. When globular proteins are in solution, their hydrophobic groups point inwards away from water.

Question 6.
Explain Lock & Key Mechanism of Enzymatic reaction.
Answer:
Lock and Key Mechanism of Enzyme: In a enzyme catalysed reaction, the starting substance is the substrate. It is converted to the product. The substrate binds to the specially formed pocket in the enzyme – the active site, this is called lock and key mechanism of enzyme action. As the enzyme and substrate form a ES complex, the substrate is raised in energy to a transition state and then breaks down into products plus unchanged enzyme.

Question 7.
Describe the Competitive & Non – Competitive Inhibitors of enzyme.
Answer:
1. Competitive Inhibitor: Molecules that resemble the shape of the substrate and may compete to occupy the active site of enzyme are known as competitive inhibitors. For Example: the enzyme that catalyses the reaction between carbon dioxide and the CO₂ acceptor molecule in photosynthesis, known as ribulose biphosphate carboxylase oxygenase (RUBISCO) is competitively inhibited by oxygen / carbon – di – oxide in the chloroplast. The competitive inhibitor is malonate for succinic dehydrogenase.

2. Non – competitive Inhibitors: There are certain inhibitors which may be unlike the substrate molecule but still combines with the enzyme. This either blocks the attachment of the substrate to active site or change the shape so that it is unable to accept the substrate. For example the effect of the amino acids alanine on the enzyme pyruvate kinase in the final step of glycolysis.

Certain non – reversible / irreversible inhibitors bind tightly and permanently to an enzyme and destroy its catalytic properties entirely. These could also be termed as poisons. Example – cyanide ions which blocks cytochrome oxidase in terminal oxidation in cell aerobic respiration, the nerve gas sarin blocks a neurotransmitter in synapse transmission.

Question 8.
Give a detailed account on Enzyme Co – factors.
Answer:
Many enzymes require non – protein components called co – factors for their efficient activity. Co – factors may vary from simple inorganic ions to complex organic molecules.
They are of three types:

1. Inorganic ions, prosthetic groups and coenzymes.
2. Holoenzyme – active enzyme with its non – protein component.
3. Apoenzyme – the inactive enzyme without its non – protein component.

Inorganic ions help to increase the rate of reaction catalysed by enzymes. Example: Salivary amylase activity is increased in the presence of chloride ions. Prosthetic groups are organic molecules that assist in catalytic function of an enzyme. Flavin adenine dinucleotide (FAD) contains riboflavin(vit B2), the function of which is to accept hydrogen. ‘Haem’ is an iron – containing prosthetic group with an iron atom at its centre. Coenzymes are organic compounds which act as cofactors but do not remain attached to the enzyme. The essential chemical components of many coenzymes are vitamins. Eg. NAD, NADP, Coenzyme A, ATP.

Question 9.
Tabulate the various features of different forms of DNA.
Answer:
The various features of different forms of DNA:

Question 10.
Compare DNA with RNA?
Answer:
Compare DNA with RNA:

DNA	RNA
1. Deoxyribose sugar is present	1. Ribose sugar is present
2. Thymine is present	2. Uracil is present
3. More stable	3. Less stable
4. Double stranded	4. Single stranded
5. Types: A – DNA, B – DNA, Z – DNA	5. Type: mRNA, tRNA, rRNA
6. Genetic material for most of living organism except few viruses	6. Genetic material for few viruses only

V. Higher Order Thinking Skills (HOTs)

Question 1.
In which form does the glucose is stored in animal cells? Specify the cells?
Answer:
Glucose is stored in the form of glycogen. Glycogen is stored in liver cells and skeletal muscles, etc.

Question 2.
State the key differences between DNA & RNA.
Answer:
The key differences between DNA & RNA:

DNA	RNA
1. Double stranded	1. Single stranded
2. Thymine is the pyrimidine base	2. Uracil is the pyrimidine base

Question 3.
Aminoacids are the monomers of proteins. Similarly mention the monomers of nucleic acids along with its composition.
Answer:
The monomer unit of nucleic acids are nucleotides, which are composed of nitrogen base, pentose sugar and phosphoric acid.

Question 4.
Complete the equations.
(a) Nitrogen base + …………… . = Nucleoside.
(b) …………… + nucleoside = Nucleotide.
(c) Glucose + fructose = …………… .
Answer:
(a) sugar
(b) phosphoric acid and
(c) sucrose.

Question 5.
What happens if the sucrose is hydrolysed?
Answer:
On hydrolysis, the glycosidic bonds in sucrose gets splitted yielding glucose and fructose.

Question 6.
Name the types of bonds.
(a) Between amino acids of protein
(b) Between carboxyl group and glycerol of fatty acids and
(c) Between glucose units of cellulose.
Answer:
(a) Peptide bond
(b) Ester bond
(c) Glycosidic bond

Question 7.
Study the following equation and name the reaction A and B.

Answer:
Reaction A is glycogenolysis. Reaction B is glycogenesis.

Question 8.
Whether waxes are found in living organisms?
Answer:
Yes. Fur, feathers, fruits, leaves, skin, and exoskeleton of insects are naturally water – proofed with a coating of wax.

Question 9.
If dsDNA has 40% Guanine. Calculate the percentage of Adenine.
Answer:
According to Chargaff’s rule:
Guanine pairs with cytosine. It Guanine is 40%, then cytosine will also be 40%. Similarly, Adenine pairs with thymine, if guanine is 40%, the remaining 60% will be Adenine. So Thymine will also be 60%.
Thus, A : T = G : C = 1
and 60 : 60 = 40 : 40 = 1.

Question 10.
In an Eukaryotic cell, totally there are 10000 RNA molecules. Calculate the number of mRNA’s and tRNA’s if the count of rRNA is 8000.
Answer:
In a cell, rRNA contributes 80%, tRNA constitutes 15% and mRNA constitutes 5%. If rRNA is 8000 (80%), then tRNA count is 1500 (15%) and mRNA is 500 (5%).

Question 11.
Despite made of two different monomers amylose and amylopectin, starch is a homopolysaccharide – Comment.
Answer:
Starch is made up of amylose and amylopectin. Both are glucose polymers, hence starch is considered as homopolysaccharides.

Question 12.
How do you call a fatty acid as saturated or unsaturated?
Answer:
If the hydrocarbon chain is single bonded, then the fatty acid is said to be saturated. In unsaturated fatty acids, the hydrocarbon chain is double bonded.

Question 13.
Enzymes are biocatalysts – Justify.
Answer:
Enzymes are globular proteins that catalyze thousands of metabolic reactions taking place within cells and organisms. Hence enzymes are called as biological catalysts.

Question 14.
Starch, cellulose, glycogen and chitin are polysaccharides found among the following. Choose the one appropriate and write against each.
(a) Cotton fibre – …………… .
(b) Exoskeleton of ant – …………… .
(c) Liver –  …………… .
(d) Peeled potato – …………… .
Answer:
(a) Cellulose
(b) Chitin
(c) Glycogen and
(d) Starch.

Question 15.
Sucrose is not a reducing sugar. Why?
Answer:
Sucrose is a non – reducing sugar since it does not possess aldehyde or ketone group, which is responsible for reducing the alkaline solutions like copper (II) sulphate.

Question 16.
A DNA segment has a total of 1000 nucleotides, out of which 240 are adenine containing nucleotides. How many pyrimidine bases this DNA segment possess?
Answer:
Pyrimidine = 500.
According to Chargaff’s rule,
A = T,
A = 240, hence T = 240.
A + T = 240 + 240 = 480.
So, G + C = 1000 – 480 = 520.
G = C, Therefore, C = \(\frac {520}{2}\) = 260.
Thus, pyrimidine = C + T = 260 + 240 = 500.

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Samacheer Kalvi 11th Bio Zoology Respiration Text Book Back Questions and Answers

I. Multiple Choice Questions
Question 1.
Breathing is controlled by ………..
(a) cerebrum
(b) medulla oblongata
(c) cerebellum
(d) pons
Answer:
(b) medulla oblongata

Question 2.
Intercostal muscles are found between the ………..
(a) vertebral column
(b) sternum
(c) ribs
(d) glottis
Answer:
(c) ribs

Question 3.
The respiratory structures of insects are ………..
(a) tracheal tubes
(b) gills
(c) green glands
(d) lungs
Answer:
(a) tracheal tubes

Question 4.
Asthma is caused due to ………..
(a) inflammation of bronchus and bronchioles
(b) inflammation of branchiole
(c) damage of diaphragm
(d) infection of lungs
Answer:
(d) infection of lungs

Question 5.
The Oxygen Dissociation Curve is ………..
(a) sigmoid
(b) straight line
(c) curved
(d) rectangular hyperbola
Answer:
(a) sigmoid

Question 6.
The Tidal Volume of a normal person is ………..
(a) 800 mL
(b) 1200 mL
(c) 500 mL
(d) 1100- 1200 mL
Answer:
(c) 500 mL

Question 7.
During inspiration, the diaphragm ………..
(a) expands
(b) unchanged
(c) relaxes to become dome-shaped
(d) contracts and flattens
Answer:
(d) contracts and flattens

Question 8.
CO₂ is transported through blood to lungs as ………..
(a) carbonic acid
(b) oxyhaemoglobin
(c) carbamino haemoglobin
(d) carboxy haemoglobin
Answer:
(c) carbamino haemoglobin

Question 9.
When 1500 mL air is in the lungs, it is called ………..
(a) vital capacity
(b) tidal volume
(c) residual volume
(d) inspiratory reserve volume
Answer:
(b) tidal volume

Question 10.
Vital capacity is ………..
(a) TV + IRV
(b) TV + ERV
(c) RV + ERV
(d) TV + TRV + ERV
Answer:
(d) TV + TRV + ERV

Question 11.
After a long deep breath, we do not respire for some seconds due to ………..
(a) more CO₂ in the blood
(b) more O₂ in the blood
(c) less CO₂ in the blood
(d) less CL in the blood
Answer:
(b) more O₂ in the blood

Question 12.
Which of the following substances in tobacco smoke damage the gas exchange system?
(a) carbon monoxide and carcinogens
(b) carbon monoxide and nicotine
(c) carcinogens and tar
(d) nicotine and tar
Answer:
(d) nicotine and tar

Question 13.
Column I represents diseases and column II represents their symptoms. Choose the correctly paired option

Column I	Column II
(P) Asthma	(i) Recurring  of bronchitis
(Q) Emphysema	(ii) Accumulation of WBCs in alveolus
(R) Pneumonia	(iii) Allergy

(a) P = iii, Q = ii, R = i
(b) P = iii, Q = i, R = ii
(c) P = ii, Q = iii, R = i
(d) P = ii, Q = i, R = iii
Answer:
(a) P = iii, Q = ii, R = i

Question 14.
Which of the following best describes the process of gas exchange in the lungs?
(a) Air moves in and out of the alveoli during breathing.
(b) Carbon dioxide diffuses from deoxygenated blood in capillaries into the alveolar air.
(c) Oxygen and carbon dioxide diffuse down their concentration gradients between blood and alveolar air.
(d) Oxygen diffuses from alveolar air into deoxygenated blood.
Answer:
(c) Oxygen and carbon dioxide diffuse down their concentration gradients between blood and alveolar air.

Question 15.
Make the correct pairs.

Column I	Column II
(P) IC	i. maximum volume of air breathe in after forced.
(Q) EC	ii. Volume of air present after expiration in lungs.
(R) VC	iii. Volume of air inhaled after expiration.
(S) FRC	iv. Volume of air present after expiration in lungs.

(a) P – i, Q – ii, R – iii, S – iv
(b) P – ii, Q – iii, R – iv , S – i
(c) P – ii, Q – iii , R – i, S – iv
(d) P – iii, Q – iv , R – i, S – ii
Answer:
(d) P – iii, Q – iv , R – i, S – ii

Make the correct pairs.

Column I	Column II
(P) Tidal volume	i. 1000 to 1100 ml
(Q) Residual volume	ii. 500 ml
(R) Expiratory reserve volume	iii. 2500 to 3000 ml
(S) Inspiratory reserve volume	iv. 1100 to 1200 ml

(a) P – ii, Q – iv , R – i, S – iii
(b) P – iii. Q – ii , R – iv , S – i
(c) P – ii, Q – iv , R – iii, S – i
(d) P – iii , Q – iv , R – i, S – ii
Answer:
(a) P – ii, Q – iv , R – i, S – iii

II. Very Short Answer Questions

Question 17.
Name the respiratory organs of flatworm, earthworm, fish, prawn, cockroach and cat.
Answer:
Flatworm – Body surface Earthworm – Moist skin Fish – Gills Prawn – Gills Cockroach – Trachea Cat – Lungs

Question 18.
Name the enzyme that catalyses the bicarbonate formation in RBCs.
Answer:
Carbonic anhydrase.

Question 19.
Air moving from the nose to the trachea passes through a number of structures. List in order of the structures.
Answer:

Question 20.
Which structure seals the larynx when we swallow?
Answer:
Epiglottis.

III. Short Answer Questions

Question 21.
Resistance in the airways is typically low. Why? Give two reasons.
Answer:
The airway resistance is low because:

• The diameter of most airways is relatively large.
• For smaller airways there are many in parallel, making their combined diameter large.
• Air has a low viscosity.

Question 22.
How the body makes long-term adjustments when living in high altitude?
Answer:
When a person lives in higher altitude, the body makes respiratory and hematopoietic . adjustment. Kidneys accelerate the production of the hormone erythropoietin which stimulate the bone marrow to produce more RBCs. This improves the binding of 02 with haemoglobin.

Question 23.
Why is pneumonia considered a dangerous disease?
Answer:
Inflammation of the lungs due to infection caused by bacteria or virus is called pneumonia. The symptoms are sputum production, nasal congestion, shortness of breath, sore throat etc. The alveoli get filled with fluid or pus, making is difficult to breathe (lung abscesses).

Question 24.
Diffusion of gases occurs in the alveolar region only and not in any other part of the respiratory system. Discuss.
Answer:
The alveolar region is highly vascular. Each alveolus is made up of highly permeable and thin layers of squamous epithelial cells. The barrier between the alveoli and the capillaries is thin and diffusion of gases takes place from higher partial pressure to low er partial pressure. Hence, gaseous exchange takes place in the aboral region only but not in any other part of the respiratory system.

Question 25.
Sketch a flow chart to show the path way of air flow during respiration.
Answer:

Question 26.
Explain the conditions which creates problems in oxygen transport.
Answer:
When a person travels quickly from sea level to elevations above 8000 ft, where the atmospheric pressure and partial pressure of oxygen are lowered, the individual responds with symptoms of acute mountain sickness (AMS)- headache, shortness of breath, nausea and dizziness due to poor binding of O₂ with haemoglobin. When the person moves on a long-term basis to mountains from sea level his body begins to make respiratory and haematopoietic adjustments.

To overcome this situation kidneys accelerate production of the hormone erythropoietin, which stimulates the bone marrow to produce more RBCs. When a person descends deep into the sea, the pressure in the surrounding water increases which causes the lungs to decrease in volume.

This decrease in volume increases the partial pressure of the gases within the lungs. This effect can be beneficial, because it tends to drive additional oxygen into the circulation, but this benefit also has a risk, the increased pressure can also drive nitrogen gas into the circulation.

This increase in blood nitrogen content can lead to a condition called nitrogen narcosis. When the diver ascends to the surface too quickly a condition called ‘bends’ or decompression sickness occurs and nitrogen comes out of solution while still in the blood forming bubbles. Small bubbles in the blood are not harmful, but large bubbles can lodge in small capillaries, blocking blood flow or can press on nerve endings.

Decompression sickness is associated with pain in joints and muscles and neurological problems including stroke. The risk of nitrogen narcosis and bends is common in scuba divers. During carbon-dioxide poisoning, the demand for oxygen increases. As the 02 level in the blood decreases it leads to suffocation and the skin turns bluish black.

Entrance Examination Questions Solved
Choose the correct answer
Question 1.
The length of human trachea is about ……….. [Gujarat CETQB]
(a) 6 inches
(b) 12 cm
(c) 12 inches
(d) 18 cm
Answer:
(b) 12 cm

Question 2.
Hamburger’s phenomenon is also known as ……….. [CPMT1988,1991, AMU2001, JLPMER 2002]
(a) HCO₃ shift
(b) Na+ shift
(c) H+ shift
(d) Chloride shift
Answer:
(d) Chloride shift

Question 3.
Oxygen carrying capacity of blood is ……….. [CPMT1990]
(a) 20%
(b) 30%
(c) 40%
(d) 50%
Answer:
(a) 20%

Question 4.
Respiratory movements are controlled by ……….. [APMEE 1978, CPMT 1998]
(a) Cerebellum
(b) Cerebrum
(c) Medulla oblongata
(d) Crura cerebri
Answer:
(c) Medulla oblongata

Question 5.
At higher CO₂ concentration, oxygen dissociation curve of haemoglobin will ……….. [CPMTX 990]
(a) Move to left
(b) Move to right
(c) Become irregular
(d) Move upwardly
Answer:
(b) Move to right

Question 6.
Chloride shift is required for transport of ……….. [CPMT 1990]
(a) Nitrogen
(b) Oxygen
(c) Carbon dioxide
(d) Carbon dioxide and oxygen
Answer:
(c) Carbon dioxide

Question 7.
Volume of air inspired or expired with each normal breath is known ……….. [CMPTl 992, AMU 2000]
(a) Inspiratory capacity
(b) Total Lung capacity
(c) Tidal volume
(d) Residual volume
Answer:
(c) Tidal volume

Question 8.
Oxygen haemoglobin dissociation curve will shift to right on decrease of ……….. [AMU 1992]
(a) Acidity .
(b) Carbon dioxide concentration
(c) Temperature
(d) pH
Answer:
(d) pH

Question 9.
Double membrane pleural sac ……….. [JKCMEE 1992]
(a) Envelops the kidneys
(b) Envelops the brain
(c) Envelops the lungs
(d) Lines the nasal passage
Answer:
(c) Envelops the lungs

Question 10.
Volume of air remaining in lungs after maximum respiratory’ effort is ……….. [JKCMEE 1992, Har. PMT 2003]
(a) Vital capacity
(b) Residual volume
(c) Total lung capacity
(d) Tidal volume
Answer:
(b) Residual volume

Question 11.
In expiration, diaphragm becomes ………..
(a) Flattened
(b) Relaxed
(c) Straightened
(d) Arched
Answer:
(b) Relaxed

Question 12.
Carbon dioxide is transported from tissues to respiratory surface by only ………..
(a) Plasma and erythrocytes
(b) Plasma
(c) Erythrocytes
(d) Erythrocytes and leucocytes
Answer:
(a) Plasma and erythrocytes

Question 13.
Respiratory centre is situated in ……….. [CPMT1980,2002, BHU1995, MPPMT1998, RPAPT2006]
(a) Cerebellum
(b) Medulla oblongata
(c) Hypothalamus
(d) Cerebrum
Answer:
(b) Medulla oblongata

Question 14.
Air is breathed through ……….. [APMEE 1999]
(a) Trachea → lung → laiynx → phaiynx → alveoli
(b) Nose → larynx → pharynx → alveoli → bronchioles
(c) Nostrils → pharynx → larynx → trachea bronchi → bronchioles → alveoli
(d) Nose → mouth → lungs.
Answer:
(c) Nostrils → pharynx → larynx → trachea bronchi → bronchioles → alveoli

Question 15.
Which is false ?
(a) Blood from right side of heart is carried to lungs by pulmonary artery
(b) Pleura is double covering of kidney
(c) Pancreas is both exocrine & endocrine gland
(d) Scurvy is due to vitamin C deficiency
Answer:
(b) Pleura is double covering of kidney

Question 16.
Volume of air breathed in and out during effortless respiration is ………..
(a) residual volume
(b) vital volume
(c) tidal volume
(d) normal volume
Answer:
(c) Tidal volume

Question 17.
Body tissue obtain oxygen from haemoglobin due to its dissociation in tissues is caused by ……….. [MPPMT 1995]
(a) Low oxygen concentration and high carbon dioxide concentration
(b) Low oxygen concentration
(c) Low carbon dioxide concentration
(d) High carbon dioxide concentration
Answer:
(b) Low oxygen concentration

Question 18.
Lungs have a number of alveoli for ………..[MPPMT 1995]
(a) Having spongy texture and proper shape
(b) More surface area for diffusion of gases
(c) More space for increasing volume of inspired air
(d) More nerve supply
Answer:
(b) More surface area for diffusion of gases

Question 19.
Presence of large number of alveoli around alveolar ducts opening into bronchioles in mammalian lungs is ………..
(a) Inefficient system of ventilation with little of residual air
(b) Inefficient system of ventilation with high percentage of residual air
(c) An efficient system of ventilation with no residual air
(d) An efficient system of ventilation with little residual air
Answer:
(d) An efficient system of ventilation with little residual air

Question 20.
During transport of CO₂ blood does not become acidic due to ………..
(a) Neutralisation of H₂CO₂ by Na₂CO₃
(b) Absorption by leucocytes
(c) Blood buffers
(d) Non-accumulation
Answer:
(c) Blood buffers

Question 21.
At high altitude, RBCs of human blood will ………..
(a) Increase in number
(b) Decrease in number
(c) Decrease in size
(d) increase in size
Answer:
(a) Increase in number

Question 22.
CO₂ is transported ………..
(a) as dissolved in blood plasma
(c) as carbamino haemoglobin
Answer:
(d) as carbamino haemoglobin and carbonic acid

Question 23.
Maximum amount 70-75% of carbon dioxide transport occursa. [RPMT1996, 1998, MPPMT1998, CPMT 1998, BV 2002]
(a) Dissolved in plasma
(b) Carbaminohaemoglobin complex
(c) Bicarbonate
(d) None of the above
Answer:
(c) Bicarbonate

Question 24.
Trachea is lined with incomplete rings of ………..
(a) Fibrous cartilage
(b) Calcified cartilage
(c) Elastic cartilage
(d) Hyaline cartilage
Answer:
(d) Hyaline cartilage

Question 25.
Oxygen and carbon dioxide are transported in blood through ………..
(a) Platelets and corpuscles
(b) RBCs and WBCs
(c) WBCs and serum
(d) RBCs and plasma
Answer:
(d) RBCs and plasma

Question 26.
About 1500 ml of air left in lungs is called ………..
(a) Tidal volume
(b) Inspiratory reserve volume
(c) Residual volume
(d) Vital capacity
Answer:
(c) Residual volume

Question 27.
Which one protects the lungs? [BHU1990]
(a) Ribs
(b) Vertebral column
(c) Sternum
(d) All the above
Answer:
(d) All the above

Question 28.
Which one has the lowest value?
(a) Tidal volume
(b) Vital capacity
(c) Inspiratory reserve volume
(d) Expiratory reserve volume
Answer:
(b) Vital capacity

Question 29.
A child was killed through asphyxiation. Post morturm confirmed it because a piece of lung put in water ………..[MPPMT 1996]
(a) Settled down
(b) Kept floating
(c) Had blood spots
(d) None of the above
Answer:
(b) Kept floating

Question 30.
Amount of oxygen present in one gram of haemoglobin is ……….. [AII MS 1997, Har. PMT, 2000]
(a) 20 ml
(b) 1-34 ml
(c) 13-4 ml
(d) None of the above
Answer:
(b) 1-34 ml

Question 31.
A molecule of haemoglobin carries how many oxygen molecules ……….. [MPPMT 1997, CFMT 2002, JCMEE 2004]
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(d) 4

Question 32.
In carbon monoxide poisoning there is ……….. [AFMC 1997]
(a) Increase in carbon dioxide concentration
(b) Decrease in oxygen availability
(c) Decrease in free haemoglobin
(d) None of the above
Answer:
(c) Decrease in free haemoglobin

Question 33.
Exchange of gases in lung alveoli occurs through ……….. [AFMC 2002]
(a) Active transport
(b) Osmosis
(c) Simple diffusion
(d) Passive transport
Answer:
(c) Simple diffusion

Question 34.
Haemoglobin is …………
(a) Vitamin
(b) Skin pigment
(c) Blood carrier
(d) Respiratory pigmentc
Answer:
(d) Respiratory pigmentc

Question 35.
Vocal cords occur in ………..
(a) Pharynx
(b) Larynx
(c) Glottis
(d) Bronchial tube
Answer:
(b) larynx

Question 36.
The cells which do not respire ……….. [4FMC 2001]
(a) Epidermal cells
(b) Sieve cells
(c) Cortical cells
(d) Erythocytes
Answer:
(d) Erythocytes

Question 37.
Hiccough (hiccup) is due to activity of ………..
(a) Intercostal muscles
(b) Food in air tract
(e) Diaphragm
(d) Inadequate oxygen in environment
Answer:
(c) Diaphragm

Question 38.
Bicarbonate formed inside erythrocytes moves out to plasma while chloride of plasma pass into erythrocytes. The phenomenon is called ………..
(a) Bicarbonate shift
(b) Carbonation
(c) Hamburger phenomenon
(d) None of the above
Answer:
(c) Hamburger phenomenon

Question 39.
Respiratory centre of brain is stimulated by ……….. [AllMS 2000]
(a) Carbon dioxide content in venous blood
(b) Carbon dioxide content in arterial blood
(c) Oxygen content in venous blood
(d) Oxygen content in arterial blood
Answer:
(d) Oxygen content in arterial blood

Question 40.
A higher CO₂ concentration of blood causes ……….. [AMU 2001]
(a) Slow diffusion of CO₂ from blood
(b) Slow transport of CO₂ from blood
(c) Slow diffusion of O, from blood
(d) Both A and B
Answer:
(c) Slow diffusion of O₂ from blood

Question 41.
Gases diffuse over the respiratory surface because of ………..
(a) O, is more in alveoli than in blood
(b) 02 is more in blood than in tissues
(c) CO₂ is more in alveoli than in blood
(d) PCO₂ is more in blood than in tissues
Answer:
(a) 02 is more in alveoli than in blood

Question 42.
Dissociation curve of 02 (which is dissociation from Hb) shifts to the rights ………..
(a) 02 concentration decrease
(b) CO₂ concentration decreases
(c) CO₂ concentration increase
(d) Chloride concentration increases
Answer:
(c) CO₂ concentration increase

Question 43.
Thoracic cage of man is formed of ……….. [MPPMT 2002]
(a) Ribs and sternum
(b) Ribs, sternum and thoracic vertebrae
(c) Ribs,sternum and lumbar vertebrae
(d) Ribs and thoracic vertebrae
Answer:
(b) Ribs, sternum and thoracic vertebrae

Question 44.
Vital capacity of lung is equal to ……….
(a) IRV + ERV + TV
(b) IRV + ERV + TV – RV
(c) IRV + ERV + TV + RV
(d) IRV + ERV
Answer:
(a) IRV + ERV + TV

Question 45.
Dead space is ………….
(a) Upper respiratory tract
(b) Nasal chambers
(c) Alveolar space
(d) Lower respiratory tract
Answer:
(a) Upper respiratory tract

Question 46.
Carbon monoxide contained in Tobacco smoke ……….. [AIEEE 2003]
(a) Is carcinogenic
(b) Causes gastric ulcers
(c) Reduces oxygen carrying capacity of blood
(d) Raises blood pressure
Answer:
(c) Reduces oxygen carrying capacity of blood

Question 47 .
What is correct?
(a) Pulmonary ventilation is equal to alveolar ventilation
(b) Alveolar ventilation is less than pulmonary ventilation
(c) Alveolar ventilation is more than pulmonary ventilation
(d) Both are variable
Answer:
(b) Alveolar ventilation is less than pulmonary ventilation

Question 48.
Increase in CO₂ concentration shall cause ………..
(a) Slower and shallower breathing
(b) Slower and deeper breathing
(e) Faster and deeper breathing
(d) No effect on breathing
Answer:
(c) Faster and deeper breathing

Question 49.
Alveoli become enlarged and damaged with reduced surface area in heavy smokers. the condition is called ………..
(a) Silicosis
(b) Emphysema
(c) Asthma
(d) Bronchitis
Answer:
(b) Emphysema

Question 50.
SARS is caused by a variant of ……….. [AIIMS 2004]
(a) Pneumococcus pneumonia
(b) Common cold by Corona virus
(c) Asthma
(d) Bronchitis
Answer:
(b) Common cold by Corona virus

Question 51.
During inspiration ……….. [JJPMER 2004, RPMT 20051
(a) Diaphragm and external muscles relax
(b) Diaphragm and internal intercostal muscles relax
(c) Diaphragm and external intercostal muscles contract
(d) Diaphragm and internal intercostal muscles contract
Answer:
(c) Diaphragm and external intercostal muscles contract

Question 52.
Mountain sickness at high altitude is due to ……….. [CPMT 2005]
(a) Excess CO₂ in blood
(b) Decreased CO₂ in air
(c) Decreased partial pressure of oxygen
(d) Decreased efficiency of haemoglobin
Answer:
(c) Decreased partial pressure of oxygen

Question 53.
Capacity of human lungs for air in a healthy person is ………..
(a) 3000 ml
(b) 1500 ml
(c) 1000 ml
(d) 500 ml
Answer:
(a) 3000 ml

Question 54.
Rate of breathing is controlled by ………….
(a) Amount of freely available oxygen
(b) Carbon dioxide in blood
(c) Muscular functions of body
(d) All the above
Answer:
(b) Carbon dioxide in blood

Question 55.
During strenuous exercise,glucose is converted into ………..
(a) Glycogen
(b) Pyruvic acid
(c) Starch
(d) Lactic acid
Answer:
(d) Lactic acid

Question 56.
How much pulmonary air is expired normally? [ PMT 2005]
(a) 70°io
(b) 20%
(c) 25%
(d) 32%
Answer:
(d) 32%

Question 57.
Which is incorrect?
(a) Presence of non-respiratory air sacs increases efficiency of respiration in birds
(b) In insects, circulation body fluids serve to distribute oxygen to tissues
(c) Principle of counter – current flow facilitates efficient respiration in gills of fishes
(d) Residual air in lungs slightly decreases the efficiency of respiration in mammals
Answer:
(b) In insects, circulation body fluids serve to distribute oxygen to tissues

Question 58.
Percentage of oxygen being carried by blood plasma is ………..
(a) 6-9%
(b) 3-6%
(c) 2-3%
(d) 1-2%
Answer:
(c) 2-3%

Question 59.
Name of the pulmonary disease in which alveolar surface area involved in gas exchange is drastically reduced due to damage in the alveolar walls: [RE-NEET 2015]
(a) Asthma
(b) Pleurisy
(c) Emphysema
(d) Pneumonia
Answer:
(c) Emphysema

Question 60.
Asthma may be attributed to ……….. [AIPMT/NEET 2016]
(a) bacterial infection of the lungs
(b) allergic reaction of the mast cells in the lungs
(c) inflammation of the trachea
(d) accumulation of fluid in the lungs
Answer:
(b) allergic reaction of the mast cells in the lungs

Question 61.
Name the chronic respiratory disorder caused mainly by cigarette smoking: [RE-NEET 2016]
(a) Emphysema
(b) Asthma
(c) Respiratory acidosis
(d) Respiratory alkalosis
Answer:
(a) Emphysema

Question 62.
Lungs are made up of air-filled sacs, the alveoli. They do not collapse even after forceful expiration. [NEET 20171]
(a) Inspiratory Reserve Volume
(b) Tidal Volume
(c) Expiratory Reserve Volume
(d) Residual Volume
Answer:
(d) Residual Volume

Samacheer Kalvi 11th Bio Zoology Respiration Additional Questions & Answers

I. Multiple Choice Questions
Choose the correct answer

Question 1.
Insects respire through ………..
(a) body surface
(b) trachea
(c) gills
(d) book lungs
Answer:
(b) trachea

Question 2.
Which of the following does not belong to the conducting zone of the respiratory system?
(a) trachea
(b) bronchioles
(c) larynx
(d) alveoli
Answer:
(d) alveoli

Question 3.
The trachea is supported by the ………..
(a) long structure
(b) cartilage
(c) multiple cartilaginous rings
(d) ligaments
Answer:
(c) multiple cartilaginous rings

Question 4.
Which of the following is right regarding the bronchioles?
(a) trachea divides into bronchioles
(b) bronchioles have cartilaginous rings
(c) bronchioles collapse when the air pressure is more
(d) bronchioles are without cartilaginous rings
Answer:
(d) bronchioles are without cartilaginous rings

Question 5.
The lungs are protected ventrally by ………..
(a) vertebral column
(b) sternum
(c) ribs
(d) diaphragm
Answer:
(b) sternum

Question 6.
The function of pleural fluid is to ………..
(a) keep the lungs intact
(b) protect the lungs from getting firm
(c) maintain the texture of the lungs
(d) reduces friction when lungs expand and contract
Answer:
(d) reduce friction when lungs expand and contract

Question 7.
Which of the following happens during inspiration?
(a) Diaphragm becomes dome shaped
(b) internal intercostal muscles contract
(c) volume of the thoracic chamber increases
(d) ribs are pulled downward
Answer:
(c) volume of the thoracic chamber increases

Question 8.
The amount of air inspired or expired with each normal breath is called the ………..
(a) residual volume
(b) inspiratory reserve volume
(c) dead space
(d) tidal volume
Answer:
(d) tidal volume

Question 9.
The normal value of IRV is ………..
(a) 500 mL
(b) 2500-3000 mL
(c) 1100-1200 mL
(d) 150 mL
Answer:
(b) 2500-3000 mL

Question 10.
UV + RV =
(a) EC
(b) TLC
(c) IC
(d) VC
Answer:
(b) TLC

Question 11.
Which of the following is not involved in gaseous exchange?
(a) expiratory reserve volume
(b) inspiratory reserve volume
(c) residual volume
(d) dead space
Answer:
(d) dead space

Question 12.
Each haemoglobin can combine with molecules of oxygen.
(a) one
(b) four
(c) three
(d) two
Answer:
(b) four

Question 13.
The ferric state of haemoglobin ………..
(a) binds with oxygen
(b) binds with carbon dioxide
(c) does not bind with oxygen
(d) does not bind with carbon dioxide
Answer:
(c) does not bind with oxygen

Question 14.
Which of the following is incorrect with regard to the formation of oxyhaemoglobin in the alveoli?
(a) high pCO₂
(b) less H+ concentration
(c) low pCO₂
(d) low temperature
Answer:
(a) high pCO₂

Question 15.
Carbon dioxide is carried in the RBCs as ………..
(a) bicarbonate ions
(b) carbon dioxide
(c) carbonic acid
(d) carbaminohaemoglobin
Answer:
(d) carbaminohaemoglobin

Question 16.
The formation of is catalysed by the enzyme carbonic anhydrase in RBCs ………..
(a) carbonates
(b) carbaminohaemoglobin
(c) carbonic acid
(d) bicarbonates
Answer:
(c) carbonic acid

Question 17.
The chemosensitive area found close to the rhythm center is highly sensitive to ………..
(a) CO₂ alone
(b) H⁺ alone
(c) O₂
(d) CO₂ and H⁺
Answer:
(d) CO₂ and H⁺

Question 18.
Which is known as the respiratory rhythm centre?
(a) cerebellum
(b) pons varoli
(c) medulla oblongata
(d) infundibulium
Answer:
(c) medulla oblongata

Question 19.
When a person travels to higher elevations, he may develop the symptoms of acute mountain sickness. This is because of ………..
(a) nitrogen narcosis
(b) high level of carbon dioxide in blood
(c) low immunity
(d) poor binding of O₂ with haemoglobin
Answer:
(d) poor binding of O₂ with haemoglobin

Question 20.
Erythropoietin hormone stimulates the bone marrow to produce more ………..
(a) WBCs
(b) RBCs
(c) Platelets
(d) Electrolytes
Ansewer:
(b) RBCs

Question 21.
When a person goes deep into the sea, he/she develops complications due to ………..
(a) increased partial pressure of O₂
(b) increase in blood nitrogen content
(c) increased partial pressure of CO₂
(d) decrease in the pressure in the surrounding water
Answer:
(b) increase in blood nitrogen content

Question 22.
Scuba divers need to face the problem of ………..
(a) nitrogen narcosis
(b) low oxygen content
(c) high carbon dioxide content
(d) lower pressure
Answer:
(a) nitrogen narcosis

Question 23.
Narrowing and inflammation of bronchi and bronchioles is called as ………..
(a) emphysema
(b) bronchitis
(c) asthma
(d) pneumonia
Answer:
(c) asthma

Question 24.
Gradual break down of the thin walls of the alveoli decreasing the total surface area of the gaseous exchange is ………..
(a) bronchitis
(b) emphysema
(c) asthma
(d) tuberculosis
Answer:
(b) emphysema

Question 25.
What causes bronchitis?
(a) Decrease in the surface area of alveoli
(b) inflammation of bronchi and bronchioles
(c) inflammation of bronchi
(d) collection of fluid in the bronchi
Answer:
(c) inflammation of bronchi

Question 26.
Which of the following is caused by bacteria?
(a) pneumonia
(b) emphysema
(c) silicosis
(d) tuberculosis
Answer:
(d) tuberculosis

Question 27.
Which of the following is the occupational respiratory disease?
(a) tuberculosis
(b) emphysema
(c) silicosis
(d) pneumonia
Answer:
(c) silicosis

Question 28.
Why does smoking affect oxygen supply to the body?
(a) haemoglobin fails to bind with O₂
(b) haemoglobin binds with carbon monoxide
(c) Nicotine makes the heart heat faster
(d) Blood vessels are narrowed
Answer:
(b) haemoglobin binds with carbon monoxide

Question 29.
COPD is the ………..
(a) emphysema and chronic bronchitis
(b) asthma and emphysema
(c) emphysema
(d) asthma, chronic bronchitis and emphysema
Answer:
(d) asthma, chronic bronchitis and emphysema

II. Fill in the Blanks

Question 1.
Oxygen is necessary for breakdown of to release energy.
Answer:
Glucose.

Question 2
……………. produce sound in human beings.
Answer:
Larynx/vocal cords.

Question 3.
……………… are the respiratory organs in most of the aquatic arthropods and molasses.
Answer:
Gills.

Question 4.
The ciliated epithelial cells lining the trachea, bronchi and bronchioles secrete …………….
Answer:
Mucus.

Question 5
divides thoracic cavity and abdominal cavity.
Answer:
Diaphragm.

Question 6.
The movement of air between the atmosphere and the lungs is known as …………
Answer:
Ventilation/breathing.

Question 7
……………. is the movement of atmospheric air into the lungs.
Answer:
Inspiration.

Question 8.
……………… In a relaxed stage, the diaphragm is shaped.
Answer:
Dome.

Question 9.
The expulsion of air from the lungs to the atmosphere is known as ……………..
Answer:
Expiration.

Question 10
………….. in an instmment used to measure the volume of air involved in breathing movements.
Answer:
Spirometer.

Question 11.
The volume of air remaining in the lungs after a forceful expiration is ……………
Answer:
Residual volume. .

Question 12.
The maximum volume of air that can be moved out during a single breath following a maximal inspiration is …………..
Answer:
Vital capacity.

Question 13.
The total volume of air a person can inhale after normal inspiration is …………….
Answer:
Inspiratory capacity.

Question 14.
The total volume of air a person can exhale after normal inspiration is ……………..
Answer:
Expiratory capacity.

Question 15.
…………….. is the total volume of air which the lungs can accommodate after forced inspiration.
Answer:
Total lung capacity.

Question 16.
The amount of air that moves into the respiratory passage per minute is called ……………
Answer:
Minute respiratory volume.

Question 17
……………… is the air that is not involved in gaseous exchange.
Answer:
Dead space.

Question 18
………………. is the pressure contributed by an individual gas in a mixture of gases.
Answer:
Partial pressure.

Question 19.
Haemoglobin belongs to the class of …………..
Answer:
Conjugated protein.

Question 20.
Haemoglobin is made up of the iron and the rest colourless protein
Answer:
Haem, globin.

Question 21.
The ferric state of haemoglobin is called …………….
Answer:
Methemoglobin.

Question 22
……………. is the respiratory pigment present in the blood.
Answer:
Haemoglobin.

Question 23.
The blood of human being is red due to the presence of …………….
Answer:
Haemoglobin.

Question 24.
Every 100 mL of oxygenated blood can deliver about mL of O, to the tissues.
Answer:
5.

Question 25.
About 70% of CO₂ transport occurs as ions.
Answer:
Bicarbonate.

Question 26.
The reversible reaction of formation of carbonic acid from carbon dioxide and water is catalyzed by the enzyme called …………………
Answer:
Carbonic anhydrase.

Question 27
center present in pons Varoli region of the brain moderates the function of respiratory rhythm center.
Answer:
Pneumotaxic.

Question 28
……………… is the hormone secreted by kidneys to stimulate bone marrow to produce more RBCs.
Answer:
Erythropoietin.

Question 29.
The increase in the nitrogen content in blood heads to a condition called ………………..
Answer:
Nitrogen narcosis.

Question 30.
The skin turns bluish black during poisoning.
Answer:
Carbon dioxide.

Question 31.
Dust, drugs, pollen grains, fish, prawns are common for asthma.
Answer:
Allergens.

Question 32.
Cigarette smoking reduces the respiratory surface of the alveolar walls and it is known as ……………….
Answer:
Emphysema.

Question 33.
Cough, shortness of breath and sputum in the lungs are the symptoms of ………………
Answer:
Bronchitis.

Question 34.
Tuberculosis is caused by ……………….
Answer:
Mycobacterium tuberculae

Question 35.
Collection of fluid between the lungs and the chest wall is the complication of the disease …………..
Answer:
Tuberculosis.

Question 36.
Long exposure to dust gives rise to inflammation leading to ………………
Answer:
Fibrosis.

Question 37
……………… and asbestosis are occupational respiratory diseases resulting from inhalation of particles of silica from sand grinding and asbestos into the respiratory tract.
Answer:
Silicosis.

Question 38
……………… causes narrowing of blood vessels resulting in increase in blood pressure and coronary heart disease.
Answer:
Nicotine.

Question 39.
……………….. Smoking lowers count in men.
Answer:
Sperm.

Question 40
…………….. is the chemical present in the cigarette smoke that causes addiction.
Answer:
Nicotine.

Question 41.
Chronic obstructive pulmonary disease is due to
Answer:
Smoking.

Question 42.
A non-smoker who inhales cigarette smoke involves in smoking.
Answer:
Passive.

Question 43.
Emphysema, chronic bronchitis and asthma, COPD, cancer may be caused due to
Answer:
Smoking.

Question 44.
Cigarette smoke contains thousands of chemicals and even small quantities of
Answer:
Arsenic.

Question 45.
The present in the cigarette smoke damages the gaseous exchange.
Answer:
Tar.

III. Answer the following Questions

Question 1.
What is excretion?
Answer:
The exchange of oxygen and carbon dioxide between environment and cells of our body, where organic nutrients are broken down oxygenatically to release energy.

Question 2.
What are the functions of the respiratory system?
Answer:
The five primary functions of the respiratory system are –

• To exchange O₂ and CO₂ between the atmosphere and the blood.
• To maintain homeostatic regulation of body pH.
• To protect us from inhaled pathogens and pollutants.
• To maintain the vocal cords for normal communication (vocalization).
• To remove the heat produced during cellular respiration through breathing.

Question 3.
The rate of breathing in aquatic animals is faster than the terrestrial animals. Give reason.
Answer:
The amount of dissolved oxygen is very low in water compared to the amount of oxygen in the air. Hence the rate of breathing in aquatic animals is faster than the terrestrial animals.

Question 4.
What is the function of hairs and mucus in the nasal cavity?
Answer:
The hairs and mucus filter the dust particles present in the air passing through the nostrils.

Question 5.
What is the function of epiglottis?
Answer:
Epiglottis is a thin elastic flap at the junction of nasopharynx and larynx. It prevents the food from entering into the larynx and avoids choking on food.

Question 6.
What are the layers of the diffusion membrane of the alveolus?
Answer:
The diffusion membrane of the alveolus is made up of three layers. They are:

• The thin squamous epithelial cells of the alveoli.
• The endothelium of the alveolar capillaries and
• The basement substance found in between them.

Question 7.
What are the cells of the squamous epithelial cells of the alveoli?
Answer:
The thin squamous epithelial cells of the alveoli are composed of Type I and Type II cells. Type I cells are very thin so that gases can diffuse rigidly through them. Type II cells are thicker. They synthesize and secrete a substance called surfactant. It lowers the surface tension in the alveoli and prevents pulmonary edema.

Question 8.
How are lungs protected?
Answer:
The lungs are light spongy tissues enclosed in the thoracic cavity surrounded by an air tight space. It is bound dorsally by the vertebral column and ventrally by the sternum, laterally by the ribs and on the lower side by the dome shaped diaphragm.

Question 9.
What is pleura? What is its function?
Answer:
The lungs are covered by double layered pleural membrane containing several layers of elastic connective tissues and capillaries. It encloses the pleural fluid which reduces friction when the lungs expand and contract.

Question 10.
What are the characteristic features of respiratory surface?
Answer:
The surface area of respiratory surface is large and richly supplied with blood vessels.

• It is extremely thin and kept moist.
• It is in direct contact with the environment.
• It is permeable to respiratory gases.

Question 11.
Explain the human respiratory system.
Answer:
The human respiratory system constitutes the conducting zone and the respiratory zone. The conducting zone includes the external nostril, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles and the lungs which contain alveoli.

The parts from the external nostrils up to the bronchioles conduct the air and hence they are called the conducting zone. This zone humidifies and warms the incoming air. The nasal cavity has fine hairs and mucus which filter dust particles in the incoming air.

At the junction of the pharynx and larynx there is a flap called epiglottis. This closes the respiratory tract while swallowing thus preventing the entry of food particles into the trachea and choking. The ciliated epithelial cells of trachea, bronchi and bronchioles secrete mucus rich in glycoprotein.

Microorganism and dust particles attach in the mucus films and are carried upwards to pass down the gullet during normal swallowing. The trachea is a semi-flexible tube supported by multiple cartilaginous rings which expands upto the mid thoracic cavity.

And the level of the 5th theoretic vertebra, it divides into right and left bronchi which divide into secondary and tertiary bronchi and further divide into terminal bronchioles and respiratory bronchioles. Bronchi have ‘c’ shaped curved Cartilage plates to ensure that the air passage does not collapse as air pressure changes during breathing. The bronchioles do not have cartilaginous rings but they have rigidity to prevent them from collapsing but are surrounded by smooth muscle which contracts or relaxes to adjust the diameter of these airways.

The fine respiratory bronchioles terminate into highly vascularised thin-walled-pouch like air sacs called alveoli. It is made up of thin squamous epithelial cells, the endothelium of the alveolar capillaries and the basement substance are found in between them.

The thin squamous epithelial cells of the alveoli, the endothelium of the alveolar capillaries and the basement substance found in between them. The thin squamous epithelial cells of the alveoli are composed of Type I and Type II cells.

Type I cells are very thin so that gases can diffuse rapidly through them. Type II cells are thicker, synthesize and secrete a substance called Surfactant. The lungs are light spongy tissues endorsed in the thoracic cavity bound dorsally by the vertebral column and ventrally by the sternum, laterally by the ribs and on the lower side by the dome shaped diaphragm. The lungs are covered by double walled pleural membrane containing several layers of elastic connective tissues and capillaries. It encloses the pleural fluid. It reduces friction when the lungs expand and contract.

Question 12.
Explain the mechanism of breathing.
Answer:
The movement of air between the atmosphere and the lungs is known as ventilation or breathing. Inspiration and expiration are the two phases of breathing. Inspiration is the movement of atmospheric air into the lungs and expiration is the movement of alveolar air that diffuse out of the lungs.

Lungs do not contain muscle fibres but expands and contracts by the movement of the ribs and diaphragm. The diaphragm is a sheet of tissue which separates the thorax from the abdomen. In a relaxed state, the diaphragm is dome shaped.

Ribs are moved by the intercostal muscles. External and internal intercostal muscles found between the ribs and the diaphragm helps in creating pressure gradients. Inspiration occurs if the pressure inside the lungs (intrapulmonary pressure) is less than the atmospheric pressure; likewise expiration takes place when the pressure within the lungs is higher than the atmospheric pressure.

Inspiration is initiated by the contraction of the diaphragm muscles and external intercostal muscles, which pulls the ribs and sternum upwards and outwards and increases the volume of the thoracic chamber in the dorso-ventral axis, forcing the lungs to expand the pulmonary volume. The increase in pulmonary volume and decrease in the intrapulmonary’ pressure forces the fresh air from outside to enter the air passages into the lungs to equalize the pressure.

This process is called inspiration. Relaxation of the diaphragm allows the diaphragm and sternum to return to its dome shape and the internal intercostal muscles contract, pulling the ribs downward reducing the thoracic volume and pulmonary volume. This results in an increase in the intrapulmonary pressure slightly above the atmospheric pressure causing the expulsion of air from the lungs. This process is called expiration.

Question 13.
Write short note on respiratory volumes.
Answer:
Tidal Volume (TV) Tidal volume is the amount of air inspired or expired with each normal breath. It is approximately 500 mL., i.e. a normal human adult can inspire or expire approximately 6000 to 8000 mL of air per minute. During vigorous exercise, the tidal volume is about 4-10 times higher.

Inspiratory Reserve volume (IRV) Additional volume of air a person can inspire by forceful inspiration is called Inspiratory Reserve Volume. The normal value is 2500-3000 mL.

Expiratory Reserve volume (ERV) Additional volume of air a person can forcefully exhale by forceful expiration is called Expiratory Reserve Volume. The normal value is 1000-1100 mL. Residual Volume (RV) The volume of air remaining in the lungs after a forceful expiration. It is approximately 1100 – 1200 mL.

Question 14.
Write a short note on respiratory capacities.
Answer:
Vital capacity (VC) the maximum volume of air that can be moved out during a single breath following a maximal inspiration. A person first inspires maximally then expires maximally. VC = ERV + TV + IRV

1. Inspiratory capacity (IC) The total volume of air a person can inhale after normal expiration. It includes tidal volume and inspiratory reserve volume. IC = TV + IRV

2. Expiratory capacity (EC) The total volume of air a person can exhale after normal inspiration. It includes tidal volume and expiratory reserve volume. EC = TV + ERV

3. Total Lung Capacity (TLC) The total volume of air which the lungs can accommodate after forced inspiration is called Total Lung Capacity. This includes the vital capacity and the residual volume. It is approximately 6000 mL. TLC = VC+ RV

4. Minute Respiratory Volume The amount of air that moves into the respiratory passage per minute is called minute respiratory volume.

Question 15.
What is dead space?
Answer:
Some of the inspired air never reaches the gas exchange areas but fills the respiratory passages where exchange of gases does not occur. This air is called dead space. Dead space is not involved in gaseous exchange. It amounts to approximately 150mL.

Question 16.
How does gaseous exchange take place in the alveoli?
Answer:
The primary site for the exchange of gases is the alveoli. The uptake of 02 and the release of CO₂ occur between the blood and tissues by simple diffusion driven by partial pressure gradient of O₂ and CO₂. Partial pressure is the pressure contributed by an individual gas in a mixture of gases.

It is represented as pO₂ for oxygen and pCO₂ for carbon- dioxide. Due to pressure gradients, O₂ from the alveoli enters into the blood and reaches the tissues. CO₂ enters into the blood from the tissues and reaches alveoli for elimination. As the solubility of CO₂ is 20-25 times higher than that of O₂, the partial pressure of CO₂ is much higher than that of O₂.

Question 17.
Write the note on respiratory pigments.
Answer:
Haemoglobin Haemoglobin belongs to the class of conjugated protein. The iron containing pigment portion haem constitutes only 4% and the rest colourless protein of the histone class globin. Haemoglobin has a molecular weight of 68,000 and contains four atoms of iron, each of which can combine with a molecule of oxygen.

Methaemoglobin If the iron component of the haem moieties is in the ferric state, than the normal ferrous state, it is called methaemoglobin. Methaemoglobin does not bind O₂. Normally RBC contains less than 1% methaemoglobin.

Question 18.
Explain the transport of oxygen In blood.
Answer:
Molecular oxygen is carried in blood in two ways: bound to haemoglobin within the red blood cells and dissolved in plasma. Oxygen is poorly soluble in water, so only 3% of the oxygen is transported in the dissolved form. 97% of oxygen binds with haemoglobin in a reversible manner to form oxyhaemoglobin (Hb0₂). The rate at which haemoglobin binds with O₂ is regulated by the partial pressure of O₂.

Each haemoglobin carries maximum of four molecules of oxygen. In the alveoli high pO₂, low pCO₂, low temperature and less H+ concentration, favours the formation of oxyhaemoglobin, whereas in the tissues low p02, high pCO₂, high H+ and high temperature favours the dissociation of oxygen from oxyhaemoglobin.

A sigmoid curve (S-shaped) is obtained when percentage saturation of haemoglobin with oxygen is plotted against pO₂. This curve is called oxygen haemoglobin dissociation curve. This S-shaped curve has a steep slope for pO₂ values between 10 and 50 mm Hg and then flattens between 70 and 100 mm Hg. Under normal physiological conditions, every 100 mL of oxygenated blood can deliver about 5 mL of O₂ to the tissues.

Question 19.
Explain the transport of carbon dioxide.
Answer:
Blood transports CO₂ from the tissue cells to the lungs in three ways:
1. Dissolved in plasma :
About 7 – 10% of CO₂ is transported in a dissolved form in the plasma.

2. Bound to haemoglobin :
About 20 – 25% of dissolved CO₂ is bound and carried in the RBCs as carbaminohaemoglobin (Hb CO₂)
CO₂ + Hb → Hb CO₂ .

3. As bicarbonate ions in plasma about 70% of CO₂ is transported as bicarbonate ions. This is influenced by pC0₂ and the degree of haemoglobin oxygenation. RBCs contain a high concentration of the enzyme, carbonic anhydrase, whereas small amounts of carbonic anhydrase is present in the plasma.

→ At the tissues the pCO₂ is high due to catabolism and diffuses into the blood to form HCO₂ and H⁺ ions. When CO₂ diffuses into the RBCs, it combines with water forming carbonic acid (H₂CO₂) catalyzed by carbonic anhydrase. Carbonic acid is unstable and dissociates into hydrogen and bicarbonate ions.

Carbonic anhydrase facilitates the reaction in both directions.

The HCO₃^– moves quickly from the RBCs into the plasma, where it is carried to the lungs. At the alveolar site where pCO₂ is low, the reaction is reversed leading to the formation of CO₂ and water. Thus CO₂ trapped as HCO₃^– at the tissue level is transported to the alveoli and released out as CO₂. Every 100 mL of deoxygenated blood delivers 4 mL of CO₂ to the alveoli for elimination.

Question 20.
How is respiration regulated?
Answer:
A specialised respiratory center present in the medulla oblongata of the hind brain called respiratory rhythm center is responsible for this regulation. Pneumotaxic centre present in ponsvaroli region of the brain moderates the function of the respiratory rhythm centre to ensure normal breathing.

The chemosensitive area found close to the rhythm centre is highly sensitive to CO₂ and H⁺. And H⁺ are eliminated out by respiratory process. Receptors associated with the aortic arch and carotid artery send necessary signals to the rhythm center for remedial action. The role of O₂ is insignificant in the regulation of respiratory rhythm.

Question 21.
Write the flow chart of the events during inspiration and expiration.
Answer:
Events in inspiration and expiration

Question 22.
What is nitrogen narcosis? What is its effect?
Answer:
When a person descends deep into the sea, the pressure in the surrounding water increases which causes the lungs to decrease in volume. This decrease in volume increases the partial pressure of the gases within the lungs. This effect can be beneficial, because it tends to drive additional oxygen into the circulation, but this benefit also has a risk, the increased pressure can also drive nitrogen gas into the circulation. This increase in blood nitrogen content can lead to a condition called nitrogen narcosis.

When the diver ascends to the surface too quickly a condition called ‘bends’ or decompression sickness occurs and nitrogen comes out of solution while still in the blood forming bubbles. Small bubbles in the blood are not harmful, but large bubbles can lodge in small capillaries, blocking blood flow or can press on nerve endings. Decompression sickness is associated with pain in joints and muscles and neurological problems including stroke.

The risk of nitrogen narcosis and bends is common in scuba divers. During carbon-dioxide poisoning, the demand for oxygen increases. As the O₂ level in the blood decreases it leads to suffocation and the skin turns bluish black.

Question 23.
Explain the disorders of the respiratory system.
Answer:
Asthma – It is characterized by narrowing and inflammation of bronchi and bronchioles and difficulty in breathing. Common allergens for asthma are dust, drugs, pollen grains, certain food items like fish, prawn and certain fruits etc. Emphysema – Emphysema is chronic breathlessness caused by gradual breakdown of the thin walls of the alveoli decreasing the total surface area of a gaseous exchange, i.e., widening of the alveoli is called emphysema. The major cause for this disease is cigarette smoking, which reduces the respiratory surface of the alveolar walls.

Bronchitis- The bronchi when it gets inflated due to pollution smoke and cigarette smoking, causes bronchitis. The symptoms are cough, shortness of breath and sputum in the lungs. Pneumonia- Inflammation of the lungs due to infection caused by bacteria or virus is called pneumonia. The common symptoms are sputum production, nasal congestion, shortness of breath, sore throat, etc.

Tuberculosis- Tuberculosis is caused by Mycobacterium tuberculae. This infection mainly occurs in the lungs and bones. Collection of fluid between the lungs and the chest wall is the main complication of this disease. Occupational respiratory disorders- The disorders due to one’s occupation of working in industries like grinding or stone breaking, construction sites, cotton industries, etc.

Dust produced affects the respiratory tracts. Long exposure can give rise to inflammation leading to fibrosis. Silicosis and asbestosis are occupational respiratory diseases resulting from inhalation of particle of silica from sand grinding and asbestos into the respiratory tract. Workers, working in such industries must wear protective masks.

Question 24.
What are the effects of smoking?
Answer:
Smoking is inhaling the smoke from burning tobacco. There are thousands of known chemicals which includes nicotine, tar, carbon monoxide, ammonia, sulphur- dioxide and even small quantities of arsenic. Carbon monoxide and nicotine damage the cardiovascular system and tar damages the gaseous exchange system.

Nicotine is the chemical that causes addiction and is a stimulant which makes the heart beat faster and the narrowing of blood vessels results in raised blood pressure and coronary heart diseases. Presence of carbon monoxide reduces oxygen supply. Lung cancer, cancer of the mouth and larynx is more common in smokers than non-smokers.

Smoking also causes cancer of the stomach, pancreas and bladder and lowers sperm count in men. Smoking can cause lung diseases by damaging the airways and alveoli and results in emphysema and chronic bronchitis. These two diseases along with asthma are often referred as Chronic Obstructive Pulmonary Disease (COPD). When a person smokes, nearly 85% of the smoke released is inhaled by the smoker himself and others in the vicinity, called passive smokers, are also affected. Guidance or counselling should be done in such users to withdraw this habit.

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Samacheer Kalvi 11th Bio Botany Cell Cycle Text Book Back Questions and Answers

I. Multiple Choice Questions
Choose the correct answer
Question 1.
The correct sequence in cell cycle is …………… .
(a) S-M-G1-G2
(b) S-G1-G2-M
(c) G1-S-G2-M
(d) M-G-G2-S
Answer:
(c) G1-S-G2-M

Question 2.
If mitotic division is restricted in G1 phase of the cell cycle then the condition is known as …………… .
(a) S Phase
(b) G2 Phase
(c) M Phase
(d) G₀ Phase
Answer:
(d) G₀ Phase

Question 3.
Anaphase promoting complex APC is a protein degradation machinery necessary for proper mitosis of animal cells. If APC is defective in human cell, which of the following is expected to occur?
(a) Chromosomes will be fragmented
(b) Chromosomes will not condense
(c) Chromosomes will not segregate
(d) Recombination of chromosomes will occur
Answer:
(b) Chromosomes will not condense

Question 4.
In S phase of the cell cycle …………… .
(a) Amount of DNA doubles in each cell
(b) Amount of DNA remains same in each cell
(c) Chromosome number is increased
(d) Amount of DNA is reduced to half in each cell
Answer:
(a) Amount of DNA doubles in each cell

Question 5.
Centromere is required for …………… .
(a) Transcription
(b) Crossing over
(c) Cytoplasmic cleavage
(d) Movement of chromosome towards pole
Answer:
(d) Movement of chromosome towards pole

Question 6.
Synapsis occur between …………… .
(a) mRNA and ribosomes
(b) Spindle fibres and centromeres
(c) Two homologous chromosomes
(d) A male and a female gamete
Answer:
(c) Two homologous chromosomes

Question 7.
In meiosis crossing over is initiated at …………… .
(a) Diplotene
(b) Pachytene
(c) Leptotene
(d) Zygotene
Answer:
(b) Pachytene

Question 8.
Colchicine prevents the mitosis of the cells at which of the following stage …………… .
(a) Anaphase
(b) Metaphase
(c) Prophase
(d) Interphase
Answer:
(b) Metaphase

Question 9.
The paring of homologous chromosomes on meiosis is known as …………… .
(a) Bivalent
(b) Synapsis
(c) Disjunction
(d) Synergids
Answer:
(b) Synapsis

Question 10.
Anastral mitosis is the characteristic feature of …………… .
(a) Lower animals
(b) Higher animals
(c) Higher plants
(d) All living organisms
Answer:
(c) Higher plants

Question 11.
Write any three significance of mitosis.
Answer:
Exact copy of the parent cell is produced by mitosis (genetically identical).

1. Genetic stability – daughter cells are genetically identical to parent cells.
2. Repair of tissues – damaged cells must be replaced by identical new cells by mitosis.
3. Regeneration – Arms of star fish.

Question 12.
Differentiate between Mitosis and Meiosis.
Answer:
Difference Between Mitosis and Meiosis:

Difference Between Mitosis and Meiosis
Mitosis	Meiosis
1. One division	1. Two divisions
2. Number of chromosomes remains the same	2. Number of chromosomes is halved
3. Homologous chromosomes line up separately on the metaphase plate	3. Homologous chromosomes line up in pairs at the metaphase plate
4. Homologous chromosome do not pair up	4. Homologous chromosome pairup to form bivalent
5. Chiasmata do not form and crossing over never occurs	5. Chiasmata form and crossingover occurs
6. Daughter cells are genetically identical	6. Daughter cells are genetically different from the parent cells
7. Two daughter cells are formed	7. Four daughter cells are formed

Question 13.
Given an account of G₀ phase.
Answer:
Some cells exit G₁ and enters a quiescent stage called G₀, where the cells remain metabolically active without proliferation. Cells can exist for long periods in G₀ phase. In G₀ cells cease growth with reduced rate of RNA and protein synthesis. The G₀ phase is not permanent. Mature neuron and skeletal muscle cell remain permanently in G₀ .Many cells in animals remains in G₀ unless called onto proliferate by appropriate growth factors or other extracellular signals. G₀ cells are not dormant.

Question 14.
Differentiate Cytokinesis in plant cells and animal cells.
Answer:
1. Cytokinesis in Plant Cells:
Division of the cytoplasm often starts during telophase. In plants, cytokinesis cell plate grows from centre towards lateral walls centrifugal manner of cell plate formation. Phragmoplast contains microtubules, actin filaments and vesicles from golgi apparatus and ER. The golgi vesicles contains carbohydrates such as pectin, hemicellulose which move along the microtubule of the pharagmoplast to the equator fuse, forming a new plasma membrane and the materials which are placed their becomes new cell wall.

The first stage of cell wall construction is a line dividing the newly forming cells called a cell plate. The cell plate eventually stretches right across the cell forming the middle lamella. Cellulose builds up on each side of the middle lamella to form the cell walls of two new plant cells.

2. Cytokinesis in Animal Cells:
It is a contractile process. The contractile mechanism contained in contractile ring located inside the plasma membrane. The ring consists of a bundle of microfilaments assembled from actin and myosin. This fibril helps for the generation of a contractile force. This force draws the contractile ring inward forming a cleavage furrow in the cell surface dividing the cell into two.

Question 15.
Write about Pachytene and Diplotene of Prophase I.
Answer:
1. Pachytene: At this stage bivalent chromosomes are clearly visible as tetrads. Bivalent of meiosis I consists of 4 chromatids and 2 centromeres. Synapsis is completed and recombination nodules appear at a site where crossing over takes place between non – sister chromatids of homologous chromosome. Recombination of homologous chromosomes is completed by the end of the stage but the chromosomes are linked at the sites of crossing over. This is mediated by the enzyme recombinase.

2. Diplotene: Synaptonemal complex disassembled and dissolves. The homologous chromosomes remain attached at one or more points where crossing over has taken place. These points of attachment where ‘X’ shaped structures occur at the sites of crossing over is called Chiasmata. Chiasmata are chromatin structures at sites where recombination has been taken place. They are specialised chromosomal structures that hold the homologous chromosomes together.

Sister chromatids remain closely associated whereas the homologous chromosomes tend to separate from each other but are held together by chiasmata. This substage may last for days or years depending on the sex and organism. The chromosomes are very actively transcribed in females as the egg stores up materials for use during embryonic development. In animals, the chromosomes have prominent loops called lampbrush chromosome.

Samacheer Kalvi 11th Bio Botany Cell Cycle Additional Questions and Answers

I. Multiple Choice Questions
Choose the correct answer:
Question 1.
Most of the neurons in the brain are in …………… stage.
(a) G₁
(b) S
(c) G₂
(d) G₀
Answer:
(d) G₀

Question 2.
Short, constricted region in the chromosome is …………… .
(a) Kinetochore
(b) Centromere
(c) Satellite
(d) Telomere
Answer:
(b) Centromere

Question 3.
Robert Brown discovered the nucleus in the cells of …………… roots.
(a) Mirabilas
(b) Orchid
(c) Moringa
(d) Oryza
Answer:
(b) Orchid

Question 4.
Scientist who described chromosomes for the first time is …………… .
(a) Robert Brown
(b) Anton van Leeuwenhoek
(c) Boveri
(d) Anton Schneider
Answer:
(d) Anton Schneider

Question 5.
Number of chromosomes in onion cell is …………… .
(a) 8
(b) 16
(c) 32
(d) 64
Answer:
(a) 16

Question 6.
Longest part of the cell cycle is …………… .
(a) Prophase
(b) G₁ Phase
(c) Interphase
(d) Sphase
Answer:
(c) Interphase

Question 7.
Eukaryotic cells divides every …………… .
(a) 12
(b) 24
(c) 1
(d) 6
Answer:
(b) 24

Question 8.
Cell cycle was discovered by …………… .
(a) Singer & Nicolson
(b) Prevost & Dumans
(c) Schleider & Schwann
(d) Boveri
Answer:
(b) Prevost & Dumans

Question 9.
G₀ stage is called as …………… stage.
(a) Quiescent
(b) Metabolically active
(c) Synthesis of DNA
(d) Replication
Answer:
(a) Quiescent

Question 10.
…………… protein acts as major check point in phase.
(a) Porins
(b) Kinases
(c) Cyclins
(d) Ligases
Answer:
(c) Cyclins

Question 11.
Replication of DNA occurs at …………… phase.
(a) G₀
(b) G₁
(c) S
(d) G₂
Answer:
(c) S

Question 12.
Condensation of interphase chromosomes into mitotic forms is done by …………… proteins.
(a) MPF
(b) APF
(c) AMF
(d) MAF
Answer:
(a) MPF

Question 13.
Which of the following is also called as direct division?
(a) Amitosis
(b) Meiosis
(c) Mitosis
(d) Reduction division
Answer:
(a) Amitosis

Question 14.
Cells of mammalian cartilage undergoes …………… .
(a) Amitosis
(b) Meiosis
(c) Mitosis
(d) Equational division
Answer:
(a) Amitosis

Question 15.
Yeast cells undergo …………… .
(a) Open mitosis
(b) Closed mitosis
(c) Amitosis
(d) Meiosis
Answer:
(b) Closed mitosis

Question 16.
…………… is the longest phase in mitosis.
(a) Anaphase
(b) Telophase
(c) Prophase
(d) Interphase
Answer:
(c) Prophase

Question 17.
The DNA protein complex present in the centromere is …………… .
(a) Cyclin
(b) Kinesis
(c) MPF
(d) Kinetochore
Answer:
(d) Kinetochore

Question 18.
…………… protein induces the break down of cohesion proteins leading to chromatid separation during mitosis.
(a) APC
(b) MPF
(c) Cyclin
(d) Kinetochore
Answer:
(a) APC

Question 19.
Regeneration of arms of star fish is due to …………… .
(a) Meiosis
(b) Amitosis
(c) Mitosis
(d) Budding
Answer:
(c) Mitosis

Question 20
…………… is called as reduction division.
(a) Meiosis
(b) Mitosis
(c) Amitosis
(d) Budding
Answer:
(a) Meiosis

Question 21.
Bivalents occur at …………… stage.
(a) Zygotene
(b) Leptotene
(c) Pachytene
(d) Diplotene
Answer:
(a) Zygotene

Question 22.
Recombination of chromosomes occur at …………… .
(a) Zygotene
(b) Leptotene
(c) Pachytene
(d) Diplotene
Answer:
(c) Pachytene

Question 23.
Terminalisation of chiasmata occurs at …………… .
(a) Zygotene
(b) Leptotene
(c) Diakinesis
(d) Pachytene
Answer:
(c) Diakinesis

Question 24.
Number of daughter cells formed at the end of Meiosis I is …………… .
(a) 2
(b) 4
(c) 1
(d) 0
Answer:
(a) 2

Question 25.
…………… division leads to genetic variability.
(a) Mitotic
(b) Amitotic
(c) Meiotic
(d) Equational
Answer:
(c) Meiotic

Question 26.
Crossing over occurs at …………… stage.
(a) Leptotene
(b) Zygotene
(c) Pachytene
(d) Diplotene
Answer:
(c) Pachytene

Question 27.
Which of the following is not a mitogen?
(a) Giberellin
(b) Ethylene
(c) Kinetin
(d) Colchicine
Answer:
(d) Colchicine

Question 28.
In plants mitosis occurs at …………… cells.
(a) Sclerenchyma
(b) Meristem
(c) Xylem
(d) Parenchyma
Answer:
(b) Meristem

Question 29.
Which of the following alone is formed in the division of plant cells?
(a) Aster
(b) Centrioles
(c) Spindle
(d) Microtubules
Answer:
(c) Spindle

Question 30.
Amphiastral type cell division is seen in …………… cells.
(a) Fungal
(b) Algal
(c) Plant cells
(d) Animal
Answer:
(d) Animal

II. Very Short Answer Type Questions (2 Marks)

Question 1.
Name the two types of nuclear division.
Answer:
The two types of nuclear division:

1. Mitosis and
2. Meiosis.

Question 2.
Define Cell Cycle.
Answer:
A series of events leading to the formation of new cell is known as cell cycle.

Question 3.
Who discovered the Cell Cycle?
Answer:
Prevost & Dumans in 1824.

Question 4.
Draw a tabular column showing the duration of various phase in the cell cycle of human cell.
Answer:
A tabular column showing the duration of various phase in the cell cycle of human cell:

Cell cycle of a proliferating human cell
Phase	Time Duration (in hrs)
1. G2	1. 11
2. S	2. 8
3. G2	3. 4
4. M	4. 1

Question 5.
Define C – Value.
Answer:
C – Value is the amount in picograms of DNA contained within a haploid nucleus.

Question 6.
Which is the longest phase of cell cycle? What happens during that phase?
Answer:
Interphase is the longest phase. Cells are metabolically active and involved in protein synthesis and growth.

Question 7.
Name the phases which comprises the Interphase.
Answer:
The phases which comprises the Interphase:

1. G₁ Phase
2. S Phase and
3. G₂ Phase.

Question 8.
Name the proteins involved in the activation of genes & their proteins to perform cell division.
Answer:
Kinases & Cyclins.

Question 9.
What do you mean by G₀ stage?
Answer:
G₀ stage is called as quiescent stage, where the cells remain metabolically active without proliferation.

Question 10.
What is the role of MPF in Cell cycle?
Answer:
Maturation Promoting Factor (MPF) brings about condensation of interphase chromosomes into the mitotic form.

Question 11.
Distinguish between Karyokinesis & Cytokinesis.
Answer:
Between Karyokinesis & Cytokinesis:

• Karyokinesis: Karyokinesis refers to the nuclear division.
• Cytokinesis: Cytokinesis refers to the cytoplasmic division.

Question 12.
Point out any two cell – types which remain G₀ phase.
Answer:
Mature neurons and Skeletal muscle cells.

Question 13.
Why amitosis is called as incipient cell division?
Answer:
Amitosis is also called incipient cell division. Since there is no spindle formation and chromatin material does not condense.

Question 14.
List out the disadvantages of Amitosis.
Answer:
The disadvantages of Amitosis:

• Causes unequal distribution of chromosomes.
• Can lead to abnormalities in metabolism and reproduction.

Question 15.
Mitosis also called as equational division – Justify.
Answer:
At the end of mitosis the number of chromosomes in the parent and the daughter (Progeny) cells remain the same so it is also called as equational division.

Question 16.
Enumerate the stages of mitosis.
Answer:
Mitosis is divided into four stages prophase, metaphase, anaphase and telophase.

Question 17.
Define an aster.
Answer:
In animal cell the centrioles extend a radial array of microtubules towards the plasma membrane when they reach the poles of the cell. This arrangement of microtubules is called an aster. Plant cells do not form asters.

Question 18.
What is metaphase plate?
Answer:
The alignment of chromosome into compact group at the equator of the cell is known as metaphase plate.

Question 19.
What is Kinetochore?
Answer:
Kinetochore is a DNA – Protein complex present in the centromere DNA, where the microtubules are attached. It is a trilaminar disc like plate.

Question 20.
How will you calculate the length of the S period.
Answer:
Length of the S period = Fraction of cells in DNA replication × generation time.

Question 21.
Which type of cell division occurs in reproductive cells? What will be the result?
Answer:
Meiosis takes place in the reproductive organs. It results in the formation of gametes with half the normal chromosome number.

Question 22.
Define Synapsis.
Answer:
In Zygotene, pairing of homologous chromosomes takes place and it is known as synapsis.

Question 23.
What do you understand by independent assortment?
Answer:
The random distribution of homologous chromosomes in a cell in Metaphase I is called independent assortment.

Question 24.
Define Mitogen. Give an example.
Answer:
The factors which promote cell cycle proliferation is called mitogen.
Example: gibberellin. These increase mitotic rate.

Question 25.
What are mitotic poisons.
Answer:
Certain chemical components act as inhibitors of the mitotic cell division and they are called mitotic poisons.

Question 26.
Distinguish between Anastral & Amphiastral.
Answer:
Between Anastral & Amphiastral:
Anastral:

1. This is present only in plant cells.
2. No asters or centrioles are formed only spindle fibres are formed during cell division.

Amphiastral:

1. This is found in animal cells.
2. Aster and centrioles are formed at each pole of the spindle during cell division.

Question 27.
Draw a simple diagram to show the Amitosis.
Answer:
The Amitosis:

III. Short Answer Type Questions (3 Marks)

Question 1.
What is the role of nucleus in the cell?
Answer:
The role of nucleus in the cell:

• Control activities of the cell.
• Genetic information copied from cell to cell while the cell divides.
• Hereditary characters are passed onto new individuals when gametic cells fuse together in sexual reproduction.

Question 2.
What are restriction points? Mention its role in Cell cycle.
Answer:
The checkpoint called the restriction point at the end of G₁ it determines a cells fate whether it will continue in the cell cycle and divide or enter a stage called G₀ as a quiescent stage and probably as specified cell or die.

Question 3.
Point out the reasons responsible for the arresting of the cell in G₁ phase?
Answer:
Cells are arrested in G₁ due to:

• Nutrient deprivation
• Lack of growth factors or density dependant inhibition
• Undergo metabolic changes and enter into G₀ state.

Question 4.
Write a note on G₀ phase.
Answer:
Some cells exit G₁ and enters a quiescent stage called G₀, where the cells remain metabolically active without proliferation. Cells can exist for long periods in G₀ phase. In G₀ cells cease growth with reduced rate of RN A and protein synthesis. The G₀ phase is not permanent. Mature neuron and skeletal muscle cell remain permanently in G₀. Many cells in animals remains in G₀ unless called onto proliferate by appropriate growth factors or other extracellular signals. G₀ cells are not dormant.

Question 5.
List out the events taking place in S – Phase.
Answer:
S Phase – Synthesis phase – cells with intermediate amounts of DNA Growth of the cell continues as replication of DNA occur, protein molecules called histones are synthesised and attach to the DNA. The centrioles duplicate in the cytoplasm. DNA content increases from 2C to 4C.

Question 6.
Distinguish between Karyokinesis & Cytokinesis.
Answer:
Karyokinesis:

1. Involves division of nucleus.
2. Nucleus develops a constriction at the center and becomes dumbellshaped.
3. Constriction deepens and divides the nucleus into two.

Cytokinesis:

1. Involves division of cytoplasm.
2. Plasma membrane develops a constriction along nuclear constriction.
3. It deepens centripetally and finally divides the cell into two cells.

Question 7.
Explain the differences between closed and open mitosis.
Answer:
Between closed and open mitosis:

1. In closed mitosis, the nuclear envelope remains intact and chromosomes migrate to opposite poles of a spindle within the nucleus. Example: Yeast and slime molds.
2. In open mitosis, the nuclear envelope breaks down and then reforms around the 2 sets of separated chromosome. Example: Most plants and animals cells.

Question 8.
What happens to plant cells at the end of Telophase in Mitosis?
Answer:
In plants, phragmoplast are formed between the daughter cells. Cell plate is formed between the two daughter cells, reconstruction of cell wall takes place. Finally the cells are separated by the distribution of organelles, macromolecules into two newly formed daughter cells.

Question 9.
Bring out the significance of Meiosis.
Answer:
The significance of Meiosis:

• Meiosis maintains a definite constant number of chromosomes in organisms.
• Crossing over takes place and exchange of genetic material leads to variations among species. These variations are the raw materials to evolution. Meiosis leads to genetic variability by partitioning different combinations of genes into gametes through independent assortment.
• Adaptation of organisms to various environmental stress.

Question 10.
Differentiate between the mitosis of Plant Cell & Animal Cell.
Answer:
Plants:

1. Centrioles are absent
2. Asters are not formed
3. Cell division involves formation of a cell plate
4. Occurs mainly at meristem.

Animals:

1. Centrioles are present
2. Asters are formed
3. Cell division involves furrowing and cleavage of cytoplasm
4. Occurs in tissues throughout the body.

Question 11.
Explain briefly about Endomitosis.
Answer:
The replication of chromosomes in the absence of nuclear division and cytoplasmic division resulting in numerous copies within each cell is called endomitosis. Chromonema do not separate to form chromosomes, but remain closely associated with each other. Nuclear membrane does not rupture. So no spindle formation. It occurs notably in the salivary glands of Drosophila and other flies. Cells in these tissues contain giant chromosomes (polyteny), each consisting of over thousands of intimately associated, or synapsed, chromatids. Example: Polytene chromosome.

Question 12.
How G₀ cells help in Closing Technology?
Answer:
Since the DNA of cells in G₀, do not replicate. The researcher are able to fuse the donor cells from a sheep’s mammary glands into G₀, state by culturing in the nutrient free state. The G₀, donor nucleus synchronised with cytoplasm of the recipient egg, which developed into the clone Dolly.

IV. Long Answer Type Questions (5 Marks)

Question 1.
Draw and label the various stages of Prophase I.
Answer:
Label the various stages of Prophase I:

Question 2.
Explain in detail about the various stages of Prophase I.
Answer:
The various stages of Prophase I:
1. Prophase I – Prophase I is of longer duration and it is divided into 5 substages – Leptotene, Zygotene, Pachytene, Diplotene and Diakinesis.

2. Leptotene – Chromosomes are visible under light microscope. Condensation of chromosomes takes place. Paired sister chromatids begin to condense.

3. Zygotene – Pairing of homologous chromosomes takes place and it is known as synapsis. Chromosome synapsis is made by the formation of synaptonemal complex. The complex formed by the homologous chromosomes are called as bivalent (tetrads).

4. Pachytene – At this stage bivalent chromosomes are clearly visible as tetrads. Bivalent of meiosis I consists of 4 chromatids and 2 centromeres. Synapsis is completed and recombination nodules appear at a site where crossing over takes place between non – sister chromatids of homologous chromosome. Recombination of homologous chromosomes is completed by the end of the stage but the chromosomes are linked at the sites of crossing over. This is mediated by the enzyme recombinase.

5. Diplotene – Synaptonemal complex disassembled and dissolves. The homologous chromosomes remain attached at one or more points where crossing over has taken place. These points of attachment where ‘X’ shaped structures occur at the sites of crossing over is called.

6. Chiasmata: Chiasmata are chromatin structures at sites where recombination has been taken place. They are specialised chromosomal structures that hold the homologous chromosomes together. Sister chromatids remain closely associated whereas the homologous chromosomes tend to separate from each other but are held together by chiasmata. This substage may last for days or years depending on the sex and organism. The chromosomes are very actively transcribed in females as the egg stores up materials for use during embryonic development. In animals, the chromosomes have prominent loops called lampbrush chromosome.

7. Diakinesis – Terminalisation of chiasmata. Spindle fibres assemble. Nuclear envelope breaks down. Homologous chromosomes become short and condensed. Nucleolus disappears.

Question 3.
Describe the process of Cytokinesis in Plant cell & Animal Cell.
Answer:
1. Cytokinesis in Plant Cell: Division of the cytoplasm often starts during telophase. In plants, cytokinesis cell plate grows from centre towards lateral walls – centrifugal manner of cell plate formation. Phragmoplast contains microtubules, actin filaments and vesicles from golgi apparatus and ER. The golgi vesicles contains carbohydrates such as pectin, hemicellulose which move along the microtubule of the pharagmoplast to the equator fuse, forming a new plasma membrane and the materials which are placed there becomes new cell wall.

The first stage of cell wall construction is a line dividing the newly forming cells called a cell plate. The cell plate eventually stretches right across the cell forming the middle lamella. Cellulose builds up on each side of the middle lamella to form the cell walls of two new plant cells.

2. Cytokinesis in Animal Cells:
It is a contractile process. The contractile mechanism contained in contractile ring located inside the plasma membrane. The ring consists of a bundle of microfilaments assembled from actin and myosin. This fibril helps for the generation of a contractile force. This force draws the contractile ring inward forming a cleavage furrow in the cell surface dividing the cell into two.

Question 4.
What are the significances of Mitosis.
Answer:
Exact copy of the parent cell is produced by mitosis (genetically identical).

1. Genetic stability – Daughter cells are genetically identical to parent cells.
2. Growth – As multicellular organisms grow, the number of cells making up their tissue increases. The new cells must be identical to the existing ones.
3. Repair of tissues – Damaged cells must be replaced by identical new cells by mitosis.
4. Asexual reproduction – Asexual reproduction results in offspring that are identical to the parent. Example Yeast and Amoeba.
5. In flowering plants, structure such as bulbs, corms, tubers, rhizomes and runners are produced by mitotic division. When they separate from the parent, they form a new individual. The production of large numbers of offsprings in a short period of time, is possible only by mitosis. In genetic engineering and biotechnology, tissues are grown by mitosis (i.e. in tissue culture).
6. Regeneration – Arms of star fish

Question 5.
Explain the various phases in Cell Cycle.
Answer:
The different phases of cell cycle are as follows:
1. Interphase: Longest part of the cell cycle, but it is of extremely variable length. At first glance the nucleus appears to be resting but this is not the case at all. The chromosomes previously visible as thread like structure, have dispersed. Now they are actively involved in protein synthesis, at least for most of the interphase. C – Value is the amount in picograms of DNA contained within a haploid nucleus.

2. G₁ Phase: The first gap phase – 2C amount of DNA in cells of G₁ The cells become metabolically active and grows by producing proteins, lipids, carbohydrates and cell organelles including mitochondria and endoplasmic reticulum. Many checkpoints control the cell cycle. The checkpoint called the restriction point at the end of G₁ it determines a cells fate whether it will continue in the cell cycle and divide or enter a stage called G₀ as a quiescent stage and probably as specified cell or die. Cells are arrested in G₁ due to:

3. Nutrient deprivation: Lack of growth factors or density dependant inhibition. Undergo metabolic changes and enter into G₀ state. Biochemicals inside cells activates the cell division. The proteins called kinases and cyclins activate genes and their proteins to perform cell division. Cyclins act as major checkpoint which operates in G₁ to determine whether or not a cell divides.

4. G₀ Phase: Some cells exit G₁ and enters a quiescent stage called G₀, where the cells remain metabolically active without proliferation. Cells can exist for long periods in G₀ phase. In G₀ cells cease growth with reduced rate of RNA and protein synthesis. The G₀ phase is not permanent. Mature neuron and skeletal muscle cell remain permanently in G₀. Many cells in animals remains in G₀ unless called on to proliferate by appropriate growth factors or other extracellular signals. G₀ cells are not dormant.

5. S phase – Synthesis phase – cells with intermediate amounts of DNA. Growth of the cell continues as replication of DNA occur, protein molecules called histones are synthesised and attached to the DNA. The centrioles duplicate in the cytoplasm. DNA content increases from 2C to 4C.

6. G₂ – The second Gap phase – 4C amount of DNA in cells of G₂ and mitosis. Cell growth continues by protein and cell organelle synthesis, mitochondria and chloroplasts divide. DNA content remains as 4C. Tubulin is synthesised and microtubules are formed. Microtubles organise to form spindle fibre. The spindle begins to form and nuclear division follows.

One of the proteins synthesized only in the G₂ period is known as Maturation Promoting Factor (MPF). It brings about condensation of interphase chromosomes into the mitotic form. DNA damage checkpoints operates in G₁ S and G₂ phases of the cell cycle.

Question 6.
List out the important features of Chromosomes.
Answer:
The four important features of the chromosome are:
1. The shape of the chromosome is specific: The long, thin, lengthy structured chromosome contains a short, constricted region called centromere. A centromere may occur any where along the chromosome, but it is always in the same position on any given chromosome. The number of chromosomes per species is fixed: For example the mouse has 40 chromosomes, the onion has 16 and humans have 46.

2. Chromosomes occur in pairs: The chromosomes of a cell occur in pairs, called homologous pairs. One of each pair come originally from each parent. Example, human has 46 chromosomes, 23 coming originally from each parent in the process of sexual reproduction. Chromosomes are copied: Between nuclear divisions, whilst the chromosomes are uncoiled and cannot be seen, each chromosome is copied. The two identical structures formed are called chromatids.

V. Higher Order Thinking Skills (HOTs)

Question 1.
Given that the average duplication time of E.coli is 20 minutes. How much time will two E.coli cells takes to become 32 cells?
Answer:

One cells takes 80 minutes to form 16 cells. If 2 cells undergoes division simultaneously, it take 160 minutes (2 hours 40 minutes) to form 32 cells.

Question 2.
Complete the cell cycle by filling the gaps with respective phases.
Answer:
X= S phase or Synthesis phase
Y= M phase or Mitosis phase
Z= G₀ phase

Question 3.
Telophase is reverse of prophase – Comment
Answer:
Events in Prophase:

1. Nuclear membrane disappears
2. Nucleolus disappear
3. Spindle fibre begins to form
4. Chromosomes threads condeme to form chromosomes

Events in Telophase:

1. Nuclear membrane reappears
2. Nucleolus reappears
3. Spindle fibre disappears
4. Chromosomes decondeme to form chromosomes

Question 4.
Name the pathological condition when uncontrolled cell division occurs.
Answer:
Uncontrolled cell division & abnormal growth of cells leads to the pathological condition called tumor or cancer.

Question 5.
Microspores are produced in the multiples of four, why?
Answer:
Microspores are haploid spores produced from diploid microspores mother cells. Each microspores mother cell (2n) undergoes meiosis producing four Microspores (n). Because a complete meiotic division yields 4 cells. Thus microspores are produced in multiples of four.

Question 6.
Between Prokaryotes & Eukaryotes, which cell has a shorter cell division time.
Answer:
Prokaryotes like bacteria undergo simple form of cell division called binary fission which will get completed with in a hour, whereas Eukaryotic cell division (mitosis) takes nearly 24 hours to get completed. Hence Prokaryotes have shorter cell division time.

Question 7.
Though Prokaryotic cell division differs from Eukaryotic cell division, both show certain common aspects during cell division. Explain.
Answer:
Whether a cell is Prokaryote or Eukaryote, while undergoing division, the following events must occur in common.

1. Replication of DNA.
2. Cytokinesis at the end of cell division.

Question 8.
An anther has 1204 pollen grains. How many Pollen mother cells must have been there to produce them?Explain.
Answer:
301 – Pollen mother cells: 301 Pollen mother cells undergo meiosis producing 1204 pollen grains. Because at the end of meiosis, each pollen mother cells produces 4 pollen grains.

Question 9.
A cell has 32 chromosomes. It undergoes mitosis. What will be the chromosome number during metaphase?
Answer:
During S phase of interphase, the genetic material of the cell is duplicated. So during metaphase, the chromosome number(chromatid number) will be doubled thus 64 chromosomes (chromatids) will be present.

Question 10.
Why sibilings show disimilarities?
Answer:
Though born to same parents, siblings show dissimilarities and variation due to the crossing over and recombination of chromosomes during meiosis.

Question 11.
Ramu’s met with an accident while riding cycle and got wounded in his leg. After few days, the wound was healed and the skin becomes normal. How?
Answer:
Ramu’s wound was healed because of the mitotic division. As a result of mitosis, new cells are produced and damaged tissues were repaired resulting the damaged skin to become normal.

Question 12.
A flower of tomato plant following the process of sexual reproduction produces 240 viable seeds. What is the minimum number of microspore mother cells involved in this process?
Answer:
60 microspore mother cells are involved in providing 240 pollen grains. Because each microspore mother cell undergoes meiosis producing four pollen grains (i.e. 60 × 4 = 240). Each pollen grain produces two male gametes of which one undergoes true fertilization of ovule producing seeds. Other male gamete participate in double fertilization.

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Samacheer Kalvi 11th Bio Zoology Digestion and Absorption Text Book Back Questions and Answers

I. Multiple Choice Questions
Question 1.
Choose the incorrect sentence from the following:
(a) Bile juice emulsifies the fat.
(b) Chyme is a digestive acidic food in stomach.
(c) Pancreatic juice converts lipid into fatty acid and glycerol.
(d) Enterokinase stimulates the secretion of pancreatic juice.
Answer:wer:
(d) Enterokinase stimulates the secretion of pancreatic juice.

Question 2.
What is chyme ?
(a) The process of conversion of fat into small droplets.
(b) The process of conversion of micelles substances of glycerol into fatty droplet.
(c) The process of preparation of incompletely digested acidic food through gastric juice.
(d) The process of preparation of completely digested liquid food in midgut.
Answer:
(c) The process of preparation of incompletely digested acidic food through gastric juice.

Question 3.
Which of the following hormones stimulate the production of pancreatic juice and bicarbonate?
(a) Angiotensin and epinephrine
(b) Gastrin and insulin
(c) Cholecysokinin and secretin
(d) Insulin and glucagon
Answer:
(c) Cholecysokinin and secretin.

Question 4.
The sphincter of Oddi guards ……………
(a) Hepatopancreatic duct
(b) Common bile duct
(c) Pancreatic duct
(d) Cystic duct
Answer:
(a) Hepatopancreatic duct

Question 5.
In small intestine, active absorption occurs in case of ……………
(a) Glucose
(b) Amino acids
(c) Na
(d) All the above
Answer:
(d) All the above

Question 6.
Which one is incorrectly matched?
(a) Pepsin – stomach
(b) Renin – liver
(c) Trypsin – intestine
(d) Ptyalin – mouth
Answer:
(b) Renin – liver

Question 7.
Absorption of glycerol, fatty acids and monoglycerides takes place by …………….
(a) Lymph vessels within villi
(b) Walls of stomach
(c) Colon
(d) Capillaries within villi
Answer:
(a) Lymph vessels within villi

Question 8.
First step in digestion of fat is ……………..
(a) Emulsification
(b) Enzyme action
(c) Absorption by lacteals
(d) Storage in adipose tissue
Answer:
(a) Emulsification

Question 9.
Enterokinase takes part in the conversion of ……………..
(a) Pepsinogen into pepsin
(b) Trypsinogen into trypsin
(c) Protein into polypetide
(d) Caseinogen into casein
Answer:
(b) Trypsinogen into trypsin

Question 10.
Which of the following combinations are not matched?

Column I	Column II
(a) Bilirubin and biliverdin	(i) intestinal juice
(b) Hydrolysis of starch	(ii) Amylases
(c) Digestion of fat	(iii) Lipases
(d) Salivary gland	(iv)Parotid

Answer:
(a) Bilirubin and biliverdin – (i) intestinal juice

Question 11.
Match column I with column II and choose the correct option

Column – I	Column – II
(P) Small intestine	(i) Largest factory
(Q)  Pancreas	(ii) Absorption of Water
(R)  Liver	(iii) Carrying electrolytic solution
(S)  Colon	(iv) Digestion and absorption

(a) (P – iv) (Q – iii) (R – i) (S – ii)
(b) (P – iii) (Q – ii) (R – i) (S – iv)
(c)(P – iv) (Q – iii) (R – i) (S – ii)
(d) (P – ii) (Q – iv) (R – iii) (S – i)
Answer:
(a) (P-iv ) ( Q – iii ) ( R- i ) ( S – ii)

Question 12.
Match column I with column II and choose the correct option

Column I	Column II
(p) Small intestine	(i) 23 cm
(q) Large intestine	(ii) 4 meter
(r) Oesophagus	(iii) 12.5 cm
(s) Pharynx	(iv)1.5 meter

(a) (P – iv) (Q – ii) (R – i) (S – iii)
(b) (P – ii) (Q – iv) (R – i) (S – iii)
(c) (P – i) (Q – iii) (R – ii) (S – iv)
(d) (P – iii) (Q – i) (R – ii)(S – iv)
Answer:
(b) (P – ii ) ( Q – iv ) ( R – i ) (S – iii)

Question 13.
Match column I with column II and choose the correct option Column – I Column – II

Column I	Column II
(p) Lipase	(i) Starch
(q) Pepsin	(ii) Cassein
(r) Renin	(iii) Protein
(s) Ptyalin	(iv) Lipid

(a) (P – iv) (Q – ii)(R – i)(S – iii)
(b) (P – iii) (Q – iv) (R – ii) (S – i)
(c) (P – iv) (Q – iii) (R – ii) (S – i)
(d) (P – iii) (Q – ii) (R – iv) (S – i)
Answer:
(c) (P – iv ) ( Q – iii ) ( R – ii) ( S – i)

Question 14.
Which of the following is not the function of liver?
(a) Production of insulin
(b) Detoxification
(c) Storage of glycogen
(d) Production of bile
Answer:
(a) Production of insulin

Question 15.
Assertion : (A) Large intestine also shows the presence of villi like small intestine.
Reason : (B) Absorption of water takes place in large intestine.
(a) Both A and B are true and B is the correct explanation of A
(b) Both A and B are true but B is not the correct explanation of A
(c) A is true but B is false
(d) A is false but B is true
Answer:
(d) A is false but B is true

Question 16.
Which of the following is not true regarding intestinal villi?
(a) They possess microvilli.
(b) They increase the surface area.
(c) They are supplied with capillaries and the lacteal vessels.
(d) They only participate in digestion of fats.
Answer:
(d) They only participate ¡n digestion of fats.

II. Short Answer Questions

Question 17.
Why are villi present in the intestine and not in the stomach?
Answer:
In small intestine digestion gets completed and the absorption of digested food materials like glucose, amino acids, fatty acids and glycerol takes place. The food materials are to be retained in the intestine by increasing the surface area. Hence villi are present in the intestine. Stomach is the temporary storing organ of food. In the stomach, HCl, pepsin, renin and lipase are secreted. These are concerned with digestion. Hence villi are not present in the stomach.

Question 18.
Bile juice contains no digestive enzymes, yet It is important for digestion. Why?
Answer:
Liver does not secrete digestive enzymes. It contains bile pigments hilirubin and hiliverdin which are the break down products of haemoglobin of dead RBCs. bile salts, cholesterol and phospholipids. Bile helps in emulsification of fats. Bile salts reduce the surface tension of fat droplets and break them into small globules. Bile also activates lipase to digest lipids.

Question 19.
List the chemical changes that starch molecule undergoes from the time it reaches the small intestine.
Answer:
In the small intestine, starch digestion gets completed. The pancreatic juice contains pancreatic amylases which acts on polysaccharide and convert into disaccharides (maltose). These cretions of the Brunner’s gland along with the secretions of the intestinal glands constitute the intestinal juice or succus entericus. It contains maltose, lactose and sucrose. These convert maltose, lactose and sucrose into monosaccharides, glucose and fructose.

In the small intestine, complex carbohydrates are converted into simple ghicose. fructose and galactose. These are absorbed by active transport.

Question 20.
How do proteins differ from fats in their energy value and their role in the body?
Answer:
The calorific value and physiological fiel value of one gram of protein are 5.65 Kcal and 4 Kcal respectively. Fat has a calorific value of 9.45 Kcal and the physiological fuel value of 9 Kcal per gram. Proteins are the source of amino acids required for growth and repair of body cells. They are stored in the body only to a certain extent. They replace the worn out protoplasm. They are important for the production of many enzymes. hormones and plasma. The catabolism of amino acids releases toxic nitrogenous wastes which are removed by the
kidneys.

Question 21.
Digestive secretions are secreted only when needed. Discuss.
Answer:
Digestive glands are exocrine glands which secrete biological catalysts called enzymes. These enzyme convert the complex. insoluble foodmaterials like carbohydrates, proteins and lipids into simplex, soluble food materials like glucose and fructose, amino acids and fatty acids and glycerol. These digestive ccretions act only when food materials are available in the alimental)’ canal.

Question 22.
Label the given diagram.
Answer:
A – Right and left hepatic duct of liver.
B – Common bile duct.
C – Pancreatic duct (duct of Wirsung)
D – Sphincter of oddi
E – Gall bladder.

In-Text Questions Solved

Question 1.
Though the bile juice of liver has no digestive enzyme but is very essential for proper digestion of food, especially of the fats. Discuss the following?
(a) What is composition of bile?
(b) How it helps in digestion of fats and other nutrients of food?
(c) How it helps in absorption of fats?
Answer:
The bile contains bile pigments (bilirubin and biliverdin) as the break down products of hemoglobin of dead RBCs, bile salts, cholesterol and phospholipids but has no enzymes. Bile helps in emulsification of fats. Bile salts reduce the surface tension of fat droplets and break them into small globules. Bile also activates lipases to digest lipids.

Question 2.
What would happen if HCl is not secreted in the stomach?
Answer:
The gastric juice contains HCl and proenzymes. The proenzyme pepsinogen, on exposure to HCl gets converted into the active enzyme pepsin which converts proteins into proteoses and peptones (peptides). The HCl provides an acidic medium (pH – 1.8) which is optimum for pepsin, kills bacteria and other harmful organisms and avoids putrifaction. So, if HCl is not secreted in stomatch, digestion of protein and destruction of harmful micro organisms will be affected.

Question 3.
What features of the small intestine enables it to absorb digested food efficiently?
Answer:
Absorption is a process by which the end product of digestion passes through the intestinal mucosa into the blood and lymph. The villi in the lumen of ileum are the absorbing units, consisting of a lacteal duct in the middle surrounded by fine network of blood capillaries. The process of absorption involves active, passive and facilitated transport.

Question 4.
What happens to the protein molecules in food, from the time it is swallowed, to the time its products are built up in the cytoplasm of a muscle cell?
Answer:
Proteins and partially digested proteins in the chyme on reaching the intestine are acted upon by the proteolytic enzymes of pancreatic juice. Trypsin hydrolyses proteins into polypeptides and peptones, while chymotrypsin hydrolyses peptide bonds associated with specific amino acids. Proteins are source of amino acids required for growth and repair of body cells. They are stored in the body only to a certain extent; large quantities are excreted as nitrogenous waste.

Textbook Activities Solved

Test for Starch :
Add a few drops of iodine to the given warm food sample. If any starch is present in the given food sample it will change the colour of the iodine from brown to blue black.

2. Test for protein :
Mix the given food sample with 3 mL of water in a test tube. Shake the mixture, and then add a few drops of Biuret solution. If protein is present, the colour of the solution will change to purple.

3. Test for glucose :
Mix the given food sample with 3 mL of water in a test tubes. Shake the mixture, and then add a few drops of Benedict’s solution. Keep the test tube in a water bath and heat carefully. If glucose is present, the colour of the solution will change from blue to green to brick red depending upon the amount of glucose.

Entrance Examination Questions Solved
Choose the correct Answer
Question 1.
How pepsin is differing from trypsin? [DPMT 1993]
(a) It digests protein in acidic medium
(b) It digests protein in alkaline medium
(c) It digests carbohydrate in acidic medium
(d) It digests carbohydrate in alkaline medium
Answer:
(a) It digests protein in acidic medium

Question 2.
Human intestine is large because ………… [DPMT1996]
(a) Bacteria in the food moves slowly
(b) Substances of food digest slowly
(c) It provide more space for the absorption of digested food
(d) It provide more space for the storage of food
Answer:
(c) It provide more space for the absorption of digested food

Question 3.
How the epidermal cells in the stomach of vertebrate animal is protected against HCl? [NCERT1981]
(a) HCl is dilute
(b) Epidermal cells defense the function of HCl
(c) HCl is neutralized in stomach
(d) Epidermal cells covered with secretion of mucus
Answer:
(d) Epidermal cells covered with secretion of mucus

Question 4.
By what the major part of mammalian teeth is made up ?
(a) Root
(b) Pulp
(c) Dentin
(d) Enamel
Answer:
(c) Dentin

Question 5.
Enterokinase takes part in the conversion of what? [BHU 2000]
(a) Pepsinogen into pepsin
(b) Trypsinogen into trypsin
(c) Protein into polypetide
(d) Casernogen into casein
Answer:
(b) Trypsinogen into trypsin .

Question 6.
Secretin stimulates production of ………… [MPPMT 2002]
(a) Saliva
(b) Gastric juice
(c) Bile
(d) Pancreatic juice
Answer:
(d) Pancreatic juice

Question 7.
Pepsin acts in ………… [HPPMT 2001]
(a) Basic medium
(b) Acidic medium
(c) Neutral medium
(d) All type of medium
Answer:
(b) Acidic medium

Question 8.
Enzyme trypsin is secreted by ………… [AFMC 20031
(a) Duodenum
(b) Liver
(c) Pancreas
(d) Stomach
Answer:
(c) Pancreas

Question 9.
The number of teeth that grow twice in the human life is ………… [AFMC 2002, 2004]
(a) 4
(b) 12
(c) 20
(d) 28
Answer:
(c) 20

Question 10.
The number of teeth that grow once in the human life is ………… [DPMT BHU 1986]
(a) 4
(b) 12
(c) 20
(d) 28
Answer:
(d) 28

Question 11.
Cholesterol is synthesised in ………… [M.RPMT 2000]
(a) Bninner’s glands
(b) Liver
(c) Spleen
(d) Pancreas
Answer:
(b) Liver

Question 12.
Largest gland in human body is ………… [JK, CMEE 2003]
(a) Liver
(b) Pancreas
(c) Pituitary
(d) Thyroid
Answer:
(a) Liver

Question 13.
Muscular contraction of alimentary canal are ………… [CMC 2003]
(a) Circulation
(b) Deglutition
(c) Churning
(d) Peristalsis
Answer:
(d) Peristalsis

Question 14.
Fatty acids and glycerol are first absorbed by ………… [BV2000J]
(a) Lymph vessels
(b) Villi
(c) Blood capillaries
(d) Hepatic portal vein
Answer:
(a) Lymph vessels

Question 15.
Trypsin changes ………… [MPPMT 1995]
(a) Proteins into peptones
(b) Fats into fatty acids
(c) Starch and glycogen into maltose
(d) Maltose into its components
Answer:
(a) Proteins into peptones

Question 16.
Secretin hormone is produced by ………… [MPPMT 1995]
(a) Stomach
(b) Liver
(c) Intestine
(d) Pancreas
Answer:
(c) Intestine

Question 17.
Narrow distal part of stomach is ………… [MPPMT 1995]
(a) Cardiac
(b) Pharynx
(c) Duodenum
(d) Pylorus
Answer:
(d) Pylorus

Question 18.
pH suitable for ptyalin actions is ………… [AFMC 1996]
(a) 6 – 8
(b) 7 – 8
(c) 3 – 2
(d) 9 – 3
Answer:
(c) 3 – 2

Question 19.
What will happen if bile duct gets choked? [DPMT 1991]
(a) Feces become dry
(b) Acidic chyme will not be neutralised
(c) There will be little digestion in intestine
(d) Little absorption of fat will occur
Answer:
(b) Acidic chyme will not be neutralised

Question 20.
Digestion of both starch and protein is carried out by ………… [AFMC 19961
(a) Gastric juice
(b) Gastric lipase
(c) Pancreatic juice
(d) Ptyalin
Answer:
(c) Pancreatic juice

Question 21.
What is common among amylase, renin and trypsin? [CPMT 2000]
(a) All proteins
(b) Proteolytic enzymes
(c) Produced in stomach
(d) Act at pH lower than 7
Answer:
(a) All proteins

Question 22.
Enterokinase is ………… [BHU l997]
(a) Pancreatic hormone
(b) Intestine hormone
(c) Pancreatic enzyme
(d) Component of Intestinal juice
Answer:
(d) Component of Intestinal juice

Question 23.
Which enzyme initiates protein digestion? [MPPMT l997
(a) Pepsin
(b) Trypsin
(c) Aminopeptidase
(d) Carboxypeptidase
Answer:
(a) Pepsin

Question 24.
Enzyme which does not directly act upon food substrate is …………
(a) Trypsin
(b) Lipase
(c) Enterokinase
(d) Arnylopsin
Answer:
(c) Enterokinase

Question 25.
Pepsin is secreted by …………… [CPMT 1997]
(a) Peptic cells
(b) Zymogen cells of stomach
(c) Zymogcn cells of duodenum
(d) Pancreas
Answer:
(a) Peptic cells

Question 26.
Pepsinogen is activated by …………..
(a) Chymotrypsin
(b) Trypsin
(c) HCl
(d) Pepsin
Answer:
(c) HCl

Question 27.
Contraction of gall bladder is induced by …………
(a) Gastrin
(b) Cholecystokinin
(c) Secretin
(d) Enterogastrone
Answer:
(b) Cholecystokinin

Question 28.
Hormone that stimulates stomach to secrete gastric juice is …………
(a) Run
(b) Enterokinase
(c) Enterogastron
(d) Gastrin
Answer:
(d) Gastrin

Question 29.
Water is largely absorbed in ………… [CPMT 1999]
(a) Stomach
(b) Oesophagus
(c) Small intestine
(d) Colon
Answer:
(d) Colon

Question 30.
HCl is secreted by ………… [DPMT 2002]
(a) Zymogen cells
(b) Kupifer’s cells
(c) Oxyntic cells
(d) Mucous cells
Answer:
(c) Oxyntic cells

Question 31.
Jaundice is a disease of ………… [APMEE 1999]
(a) Kidney
(b) Liver
(c) Pancreas
(d) Duodenum
Answer:
(b) Liver

Question 32.
Which is different? [BHU 1999]
(a) Gastrin
(b) Secretin
(c) Ptyalin
(d) Glucagon
Answer:
(C) Ptyalin

Question 33.
Gastrin is ………… [BHU 1999]
(a) Hormone
(b) Enzyme
(c) Nutrient
(d) Digestive secretion
Answer:
(a) Hormone

Question 34.
Saliva contains enzyme ………… [CPAÍT 2003]
(a) Enterokinase
(b) Ptyalin/ Amylase
(c) Chymotrypsin
(d) Lipase
Answer:
(b) Ptyalin) Amylase

Question 35.
In human being cellulose is digested by …………
(a) Enzyme
(b) Symbiotic bacteria
(c) Symbiotic protozoAnswer:
(d) None of the above
Answer:
(b) Symbiotic bacteria

Question 36.
Enzyme lactase occurs in ………… [MPPMT 2000]
(a) Saliva
(b) Pancreatic juice
(c) Intestinal juice
(d) Stomach
Answer:
(c) Intestinal juice

Question 37.
Protein I enzyme is absent in ………… [MPPMT 2000]
(a) Saliva
(b) bile
(c) Pancreatic juice
(d) Intestinal juice
Answer:were:
(b) Bile

Question 38.
Dental formula shows ………… [MPPMT 2000]
(a) Structure of teeth
(b) Monophyodont or diphyodont condition
(c) Number and type of teeth in both jaws
(d) Number and type of teeth in one half of both jaws
Answer:
(c) Number and type of teeth ¡n both jaws

Question 39.
pH of gastric juice / stomach is …………
(a) 1.5-3.0
(b) 5.0-6.8
(c) 7.0 -9.0
(d) 6.0 -8.0
Answer:
(a) 1.5 -3.0

Question 40.
In case of taking food rich in lime juice, the action of ptyalin on starch is ………… [AuMS 2000]
(a) Enhanced
(b) Reduced
(c) Unaffected
(d) Stopped
Answer:
(b) Reduced

Question 41.
Bile salts take part in ………… [AMU 2000]
(a) Digestion of carbohydrates
(b) Brokedowri of proteins
(c) Emulsification of fat
(d) Absorption of glycerol
Answer:
(c) Emulsification of fat

Question 42.
Digestive juice contains catalytic agents called ………… [PMT 000]
(a) Vitamins
(b) Hormones
(c) Enzymes
(d) Nitrates
Answer:
(c) Enzymes

Question 43.
Which is not the function of liver? [DPMT 2001]
(a) Production of insulin
(b) Detoxification
(c) Storage of glycogen
(d) Production of bile
Answer:
(a) Production of insulin

Question 44.
Fat absorbed from gut is trAnswer:ported in blood …………
(a) Micelles
(b) Liposomes
(c) Chemomicrons
(d) Chlymicrons
Answer:
(a) Micelles

Question 45.
In small intestine, active absorption occurs in case of ………… [AMU 2001]
(a) Glucose
(b) Amino acids
(c) Na+
(d) All the above
Answer:
(d) All the above

Question 46.
Which one is not matched? [Har. PMT 2002]
(a) Pepsin – stomach
(b) Renin – liver
(e) Trypsin – intestine
(d) Ptyalin – mouth
Answer:
(b) Renin – liver

Question 47.
What is cholecystokinin?
(a) Bile pigment
(b) Gastro-intestinal hormone
(c) Enzyme
(d) Lipid
Answer:
(b) Gastro-intestinal hormone

Question 48.
Secretion of gastric juice is controlled by ………… [CPMT2002J
(a) Enterogesterone
(b) Cholecystokinin
(c) Gastrin
(d) Pepsin
Answer:
(c) Gastrin

Question 49.
Which one is wisdom teeth? [CPMT 2002]
(a) Third molar, four in number
(b) Third molar, two in number
(c) Second molar, four in number
(d) Second molar, two in number
Answer:
(a) Third molar, four in number

Question 50.
in humans, digestion is ………… [BHU 2002]
(a) Intercellular
(b) Intracellular
(c) Extracellular
(d) Both A and B
Answer:
(b) intracellular

Question 51.
Gall bladder takes part in ………… [RPMT 2002]
(a) Secretion of bile
(b) Storage of bile
(c) Formation of bile salts
(d) Formation of enzymes
Answer:
(b) Intracellular .

Question 51.
Gall bladder takes part in ………… [RPMT 2002]
(a) Secretion of bile
(b) Storage of bile
(c) Formation of bile salts
(d) Formation of enzymes
Answer:
(b) Storage of bile

Question 52.
Renin acts on milk protein and changes ………… [JIPMER 2002]
(a) Caesinogen into caesin
(b) Caesin into paracaesin
(c) Caesinogen into paracaesin
(d) Paracaesin into Caesinogen
Answer:
(a) Caesinogen into caesin

Question 53.
Glucose is stored in liver as ………… [AFMC 2003]
(a) Starch
(b) Glycogen
(c) Cellulose
(d) Sucrose
Answer:
(b) Glycogen

Question 54.
Absorption of glycerol, fatty acids and monoglycerides takes place by …………
(a) Lymph vessels within villi
(b) Walls of stomach
(c) Colon
(d) Capillaries within villi
Answer:
(a) Lymph vessels within villi

Question 55.
Which ones are bile salts?
(a) Haemoglobin and biliverdin
(b) Bilirubin and biliverdin
(c) Bilirubin and Haemoglobin
(d) Sodium glycolate and taurocholate
Answer:
(d) Sodium glycolate and taurocholate

Question 56.
Ptyalin is inactivated by a component of gastric juice called ……………. [Har PMT 2003]
(a) Pepsin
(b) HCl
(c) Renin
(d) Mucus
Answer:
(b) HCl

Question 57.
Epithelial cells involved in absorption of digested food have on their free surface ……………. [A IEEE 2003]
(a) Zymogen granules
(b) Pinocytic vesicles
(c) Phagocytic vesicles
(d) Microvilli
Answer:
(d) Microvilhi

Question 58.
First step in digestion of fat is …………… [BIIU 2003]
(a) Emulsification
(b) Enzyme action
(c) Absorption by lacteals
(d) Storage in adipose tissue
Answer:
(a) Emulsification

Question 59.
DNA-ase and RNA-ase are enzymes produced by …………… [BHU 2003]
(a) Salivary glands
(b) Pancreas
(c) Stomach
(d) Intestine
Answer:
(b) Pancreas

Question 60.
Carboxypeptidase is secreted by …………….
(a) Pancreas
(b) Stomach
(c) Salivary glands
(d) Intestine
Answer:
(a) Pancreas

Question 61.
Secretin and Cholecystokinin are digestive hormone. They are secreted in …………
(a) Pyloric stomach
(b) Duodenum
(c) Ileum
(d) Oesophagus
Answer:
(b) Duodenum

Question 62.
Crown of teeth is covered by ………… [AFMC 2005]
(a) Dentin
(b) Enamel
(c) (a) and (b) both
(d) None of these
Answer:

Question 63.
Both the crown and root of a teeth is covered by a layer of bony hard substance called ………… [J&K CET 2005]
(a) Enamel
(b) Dentin
(c) Bony socket
(d) Cementum
Answer:
(d) Cementum

Question 64.
Lysozymes are found in ………… [MPPMT 2004]
(a) Saliva
(b) Tears
(c) (a) and (b) both
(d) Mitochondria
Answer:
(c) (a) and (b) both

Question 65.
Which of the following is not present in pancreatic juice? [HPPMT 2005]
(a) Trypsinogen
(b) Chymotrypsin
(c) Parasitic
(d) lipase
Answer:
(c) Parasitic

Question 66.
Which of the following statement is not correct? [NEET 2015]
(a) Brunner’s glands are present in the submucosa of stomach and secrete pepsinogen
(b) Goblet cells are present in the mucosa of intestine and secrete mucus.
(c) Oxyntic cells are present in the mucosa of stomach and secrete HCI.
(d) Acini are present in the pancreas and secrete carboxypeptidse.
Answer:
(a) Brunner’s glands are present in the submucosa of stomach and secrete pepsinogen

Question 67.
Which hormones stimulate the production of pancreatic juice and bicarnates? [NEET20I6]
(a) Cholecystokinin and secretin
(b) Insulin and glucagon
(c) Angiotensin and epinephrine
(d) Gastnn and Insulin
Answer:
(a) Cholecystokinin and secretin

Question 68.
In the stomach, gastric acid is secreted by the ………… [AIPMT / NEET 2016]
(a) gastrin secreting cells
(b) parietal cells
(c) peptic cells
(d) acidic cells
Answer:
(b) parietal cells

Question 69.
The enzymes that is not present is succus entericus is ……………… [RE-A IPMTNEE T 2015]
(a) lipase
(b) maltase
(c) nucleases
(d) nucleosîdase
Answer:
(c) nucleases

Question 70.
Which of the following are not polymerase? [NEET 2017]
(a) Proteins
(b) Polysaccharides
(c) Lipids
(d) Nucleic acids
Answer:
(c) Lipids3

Question 71.
A baby aged two years is admitted to play school and passes through a dental check-up. The dentist observed that the boy had twenty teeth. Which teeth were absent? [NEET 2017]
(a) Canines
(b) Pre-Molars
(c) Molars
(d) Incisors
Answer:
(b) Pre-Molars

Question 72.
Which cells of crypts of Leiberkuhn’ secrete antibacterial lysozyme? [NEET 2017]
(a) Paneth cells
(b) Zymase cells
(c) Kupifer cells
(d) Argentaffin cells
Answer:
(a) Paneth cells

Question 73.
The hepatic portal veins drains blood to liver from ………… [NEET 2017]
(a) Stomach
(b) Kidneys
(c) Intestine
(d) Heart
Answer:
(c) Intestine

Question 74.
Which of the following options best represent the enzyme composition of pancreatic juice? [NEET2O17]
(a) Amylase, pepsin, trypsinogen, maltase
(b) Peptidase, Amylase, pepsin, renin
(c) Lipase, amylase, trypsinogen, procarboxypeptidase
(d) Amylase, peptidase, trypsinogen, renin.
Answer:
(c) Lipase, amylase, trypsinogen, procarboxypeptidase

Question 75.
Good vision depends on adequate intake of carotene rich food. Select the best option from the following statements. [NEET 2017]
(a) Vitamin A derivatives are formed from carotene.
(b) The photo pigments are embedded in the membrane discs of the inner segments.
(c) Retinal is a derivative of vitamin A
(d) Retinal is light absorbing part of all the visual photopigments.
OPTION
(a) a, c and d
(b) a and e.
(c) b, e and d
(d) a and b
Answer:
(a) a, c and d

Samacheer Kalvi 11th Bio Zoology Digestion and Absorption Additional Questions & Answers

I. Multiple Choice Questions
Choose the correct Answer
Question 1.
Which of the following is the last phase of the process of digestion?
(a) ingestion
(b) assimilation
(c) eqestion
(d) digestion
Answer:
(c) eqestion

Question 2.
Which of the following teeth are the cutting teeth?
(a) incisors
(b) canines
(c) premolars
(d) molars
Answer:
(a) incisors

Question 3.
Plague formed on the teeth are mineral salts of ……………..
(a) sodium
(b) magnesium and manganese
(c) potassium
(d) calcium and magnesium
Answer:
(d) calcium and magnesium

Question 4.
Which muscle regulates the opening of oesophagus into the stomach?
(a) pyloric sphincter
(b) cardiac sphincter
(c) anal sphincter
(d) epiglottis
Answer:
(a) pyloric sphincter

Question 5.
The ‘V’ shaped part of the small intestine is …………
(a) ileum
(b) jejunum
(c) duodenum
(d) colon
Answer:
(c) duodenum

Question 6.
…………….. is the longest part of the small intestine
(a) Ileum
(b) Jejunum
(c) Duodenum
(d) Rectum
Answer:
(a) Ileum

Question 7.
Villi are concerned with
(a) secretion of enzymes
(b) secretion of mucus
(c) digestion of food
(d) absorption of digested food
Answer:
(d) absorption of digested food.

Question 8.
Peyer’s patches produce
(a) monocytes
(b) lymphocytes
(c) basophils
(d) neutrophils
Answer:
(b) lymphocytes

Question 9.
Which of the following are non-functional in human beings?
(a) Small intestine
(b) Duodenum
(c) lleum
(d) Vermiform appendix
Answer:
(d) Vermiform Appendix

Question 10.
…………… is formed of loose connective tissue containing nerves, blood, lymph vessels and sympathetic nerve fibres that control the secretions of intestinal juice.
(a) Serosa
(b) Sub-mucosa
(c) Mucosa
(d) Muscularis
(b) Sub-mucosa

Question 11.
………… secrete HCl in the stomach.
(a) Peptic cells
(b) Goblet cells
(c) Oxyntic cells
(d) Zymogen cells
Answer:
(c) Oxyntic cells

Question 12.
…………. stores bile secreted by the liver.
(a) Pancreatic duct
(b) Duodenum
(c) Hepatic duct
(d) Gall bladder
Answer:
(d) Gall bladder

Question 13.
Detoxification is one of the functions of –
(a) small intestine
(b) liver
(c) pancreas
(d) stomach
Answer:
(b) liver

Question 14.
Which is the antibacterial agent present in the saliva?
(a) Ptyalin
(b) Mucus
(c) Lysozyme
(d) Bicarbonates
Answer:
(c) Lysozyme

Question 15.
Salivary amylase hydrolyses …………
(a) proteins
(b) carbohydrate
(c) fats
(d) vitamins
Answer:
(b) carbohydrate

Question 16.
Pepsin is a enzyme ………….
(a) amylolytic
(b) lipolytic
(c) proteolytic
(d) proenzyme
Answer:
(c) proteolytic

Question 17.
Which enzyme acts on milk protein in infants in the presence of calcium ions?
(a) Pepsin
(b) Chymotrypsin
(c) Lipase
(d) Renin
Answer:
(d) Renin

Question 18.
Which is the active enzyme?
(a) Pepsinogen
(b) Trypsin
(c) Trypsinogen
(d) Chymotrypsinogen
Answer:
(b) Trypsin

Question 19.
What are the break down products of haemoglobin?
(a) Bile salts
(b) Bilirubin and biliverdin
(c) Phospholipids
(d) Cholesterol
Answer:
(d) Cholesterol

Question 20.
Which of the following does not contain any enzyme?
(a) Gastric juice
(b) Bile
(c) Pancreatic juice
(d) Succus entericus
Answer:
(b) Bile

Question 21.
Identify the odd one ……….
(a) maltose
(b) lactose
(c) sucrose
(d) sucrase
Answer:
(d) sucrase

Question 22.
At the end of digestion, fats are converted into ………..
(a) amino acids
(b) glycerol and fatty acids
(c) glucose
(d) galactose
Answer:
(b) glycerol and fatty acids

Question 23.
Protein coated fat globules are called …………
(a) micelles
(b) villi
(c) microvilli
(d) chylomicrons
Answer:
(d) chylomicrons

Question 24.
The calorific value of carbohydrates is ………….
(a) 9.45
(b) 4.1
(c) 3.5
(d) 6.5
Answer:
(b) 4.1

Question 25.
Retaining feces in the rectum due to poor intake of fibre in the diet is called ………..
(a) vomiting
(b) indigestion
(c) constipation
(d) diarrhoea
Answer:
(c) constipation

Question 26.
Which one of the following occurs due to reverse peristalsis?
(a) Vomiting
(b) Diarrhoea
(c) Constipation
(d) Indigestion
Answer:
(a) Vomiting

Question 27.
The failure of the liver to break down haemoglobin is called as ……………….
(a) gall stone
(b) jaundice
(c) appendicitis
(d) hernia
Answer:
(c) appendicitis

Question 28.
Degeneration and destruction of liver cells resulting in abnormal blood vessel and bile duct leading to the formation of fibrosis is known as ………………
(a) gall stones
(b) jaundice
(c) hernia
(d) liver cirrhosis
Answer:
(d) liver cirrhosis

Question 29.
What causes obstruction in the cystic duct, hepatic duct and hepato-pancreatic duct?
(a) Gall stones
(b) Jaundice
(c) Hernia
(d) Liver cirrhosis
Answer:
(a) Gall stones

Question 30.
Appendicitis is the inflammation of the ……………..
(a) caecum
(b) liver
(c) appendix
(d) rectum
Answer:
(c) appendix

Question 31.
Diarrhoea happens due to ……………….
(a) taking in of more volume of water
(b) defective liver
(c) inflammation of the appendix
(d) inability of colon to absorb fluid from the feces
Answer:
(d) inability of colon to absorb fluid from the feces

Question 32.
The erosion of the mucosa in the stomach or duodenum is referred to as ……………….
(a) stomach ache
(b) peptic ulcer
(c) duodenal cancer
(d) diarrhoea
Answer:
(b) peptic ulcer

Question 33.
The storage of excess of body fat in adipose tissue is ……………
(a) peptic ulcer
(b) kwashiorkor
(c) jaundice
(d) obesity
Answer:
(d) obesity

II. Fill in the Blanks

Question 1.
Breakdown of macromolecules of food into micromolecules is ………….
Answer:
Digestion.

Question 2.
The tearing teeth are called as ……………….
Answer:
Canines

Question 3.
The deposition of calcium and magnesium salts on the teeth forms a hard layer called ……………..
Answer:
Tartar/calculus/plaque.

Question 4.
The oral cavity leads into a short common passage for food and air called
Answer:
Pharynx.

Question 5.
Two masses of lymphoid tissues called are located at the sides of the pharynx.
Answer:
Tonsils.

Question 6.
The opening of the stomach into the duodenum is guarded by the ……………
Answer:
Pyloric sphincter.

Question 7.
The inner wall of stomach has many folds called which unfolds to accommodate a large meal.
Answer:
Gastric rugae.

Question 8.
The wall of the duodenum has glands which secrete mucus and enzymes.
Answer:
Brunner’s.

Question 9.
The ileal mucosa has numerous vascular projections called …………..
Answer:
Villi.

Question 10
are the mucus secreting goblet cells and lymphoid tissue which produce lymphocytes.
Answer:
Peyer‘s patches.

Question 11.
The wall of the small intestine bears crypts between the base of the villi called …………….
Answer:
Crypts of Leiberkuhn.

Question 12.
Caecum and vermiform appendix are the important site for digestion in herbivores.
Answer:
Cellulose.

Question 13.
The dilations of colon are called ……………..
Answer:
Haustra

Question 14.
The enlargement of anal column causes …………..
Answer:
Piles / haemorrhoids

Question 15
………. is the outermost layer of the wall of the alimentary canal.
Answer:
Serosa.

Question 16.
The enzyme secreting cells of gastric glands are called cells.
Answer:
Peptic or zymogen.

Question 17.
The cells secrete HCl in the stomach.
Answer:
Parietal or oxyntic.

Question 18.
The is the largest gland in our body.
Answer:
Liver.

Question 19.
Each lobe of liver is covered by a thin connective tissue sheath called the ……………
Answer:
Glisson’s capsule.

Question 20.
The detoxifies toxic substances.
Answer:
Liver.

Question 21.
The opening of the hepato-pancreatic duct into the duodenum is guarded by a sphincter called the sphincter of
Answer:
Oddi.

Question 22
gland is both exocrine and endocrine.
Answer:
Pancreas.

Question 23.
The successive waves of muscular contraction by which bolus passes down through the oesophagus is called
Answer:
Peristalsis.

Question 24
activates pepsinogen.
Answer:
HCl.

Question 25.
Renin converts caseinogen into casein is the presence of ions.
Answer:
Calcium.

Question 26
activates trypsinogen.
Answer:
Enterokinase.

Question 27.
Trypsin hydrolyses proteins into polypeptides and
Answer:
Peptones.

Question 28.
mucosa into the blood and lymph.
Answer:
Absorption.

Question 30.
The chylomicrons are transported into the within the intestinal villi.
Answer:
Lacteals.

Question 31.
Large intestine absorbs more amount of vitamins, some minerals and certain
drugs.
Answer:
Water.

Question 32.
The eqestion of feces through the anal opening is called ……………..
Answer:
Defecation

Question 33
are the major source of cellular fuel which provides energy.
Answer:
Carbohydrates.

Question 34
are the best reserved food stored in our body.
Answer:
Lipids.

Question 35.
Marasmus is the deficiency disease.
Answer:
Protein.

Question 36
is the digestive disorder in which the food is not properly digested leading to a feeling of fullness of stomach.
Answer:
Indigestion.

Question 37
is caused due to hepatitis viral infection.
Answer:
Jaundice.

Question 38.
The crystallized cholesterol in the bile forms …………….
Answer:
Gall stones.

Question 39
…………. is a structural abnormality in which superior part of the stomach protrudes slightly
Answer:
Hiatus hernia.

Question 40.
Treatment for diarrhoea is known as therapy.
Answer:
Oral hydration.

Question 41
refers to an eroded area of the tissue lining in the stomach or duodenum.
Answer:
Peptic ulcer.

Question 42.
Ulcer is mostly due to infection caused by the bacterium
Answer
Helicobacter pylori.

Question 43
…………… is caused due to the storage of excess of body fat in adipose tissue.
Answer:
Obesity.

III. Answer the following Questions

Question 1.
What are the uses of food?
Answer:
The food we eat provides energy and organic substances for growth and the replacement of worn out and damaged tissues. It regulates and coordinates the various activities that take place in the body.

Question 2.
What are the components of food?
Answer:
The components of food are carbohydrates, proteins, lipids, vitamins, minerals, fibre and water.

Question 3.
Why do we need a digestive system?
Answer:
The food that we eat are macromolecules, and inabsorbable. These are to be broken down . into smaller micro-molecules in absorbable forms. This is done by digestive system.

Question 4.
Why do plants not require a digestive system?
Answer:
Plants are autotrophs. They prepare their own food using CO₂, H₂O in the presence of sunlight trapped by the chlorophyll pigment present in the leaves. There is no need of digestive system for plants as they use the starch as such.

Question 5.
What is the function of the digestive system?
Answer:
The function of the digestive system is to bring the nutrients, water and electrolytes from the external environment into every cell in the body through the circulatory system.

Question 6.
Define:
(a) Ingestion : The taking in of food is called ingestion.
(b) Digestion : The break down of the macromolecules into micromolecules by the action of digestive enzymes is called digestion.
(c) Absorption : The taking in of digested food materials into the blood stream is called absorption.
(d) Assimilation : The conversion of absorbed food materials into components of cells is called assimilation.
(e) Egestion : The elimination of the undigested substances from the body is called egestion.

Question 7.
What is thecodont dentition?
Answer:
Every tooth in human beings is embedded in a socket in the jaw bone. This type of attachment is called the codont dentition.

Question 8.
What is diphyodont dentition?
Answer:
Human beings and many mammals form two sets of teeth during their life time, a set of 20 temporary milk teeth which gets replaced by a set of 32 permanent teeth. This type of dentition is called diphyodont dentition.

Question 9.
What is heterodont dentition?
Answer:
Human beings have four different types of teeth namely incisors, canines, premolars and molars. This is known as heterodont dentition.

Question 10.
What is known as the dental formula of human beings?
Answer:
The arrangement of teeth in each half of the upper and lower jaw in the order of I, C, P and M can be represented by the dental formula. The dental formula of man is 2123 / 2123.

Question 11.
What is gingivitis?
Answer:
Mineral salts like calcium and magnesium are deposited on the teeth and form a hard layer of ‘tartar’ or calculus called plaque. If the plaque formed on teeth is not removed regularly, it would spread down the tooth into the narrow gap between the gums and enamel and causes inflammation, called gingivitis, which leads to redness and bleeding of the gums and to bad smell.

Question 12.
What is enamel?
Answer:
The hard chewing surface of the teeth is made of enamel and helps in mastication of food.

Question 13.
What is the function of tongue?
Answer:
Tongue helps in intake of food, chew and mix food with saliva, to swallow food and also to speak. The upper surface of the tongue has small projections called papillae with taste buds.

Question 14.
What is the function of the cardiac sphincter?
Answer:
A cardiac sphincter or gastro esophageal sphincter regulates the opening of oesophagus into the stomach.

Question 15.
What is gastro oesophagus reflex disorder?
Answer:
If the cardiac sphincter does not contract properly during the churning action of the stomach the gastric juice with acid may flow back into the oesophagus and cause heart bum, resulting in GERD (Gastro Oesophagus Reflex Disorder).

Question 16.
What is the function of the pyloric sphincter?
Answer:
The opening of the stomach into the duodenum is guarded by the pyloric sphincter. It periodically allows partially digested food to enter the duodenum and also prevents regurgitation of food.

Question 17.
What are gastric rugae?
Answer:
The inner wall of stomach has many folds called gastric rugae which unfolds to accommodate a large meal.

Question 18.
Write a short note on the small intestine.
Answer:
The small intestine assists in the final digestion and absorption of food. It is the longest part of the alimentary canal and has three regions, a ‘U’ shaped duodenum (25 cm long), a long coiled middle portion jejunum (2.4m long) and a highly coiled ileum (3.5 m long).

The wall of the duodenum has Brunner’s glands which secrete mucus and enzymes. Ileum is the longest part of the small intestine and opens into the caecum of the large intestine.

The ileal mucosa has numerous vascular projections called villi which are involved in the process of absorption and the cells lining the villi produce numerous microscopic projections called microvilli giving a brush border appearance that increase the surface area enormously.

Along with Villi, the ileal mucosa also contain mucus secreting goblet cells and lymphoid tissue known as Peyer’s patches which produce lymphocytes. The wall of the small intestine bears crypts between the base of villi called crypts of Leiberkuhn.

Question 19.
Explain the structure of the large intestine.
Answer:
The large intestine consists of caecum, colon and rectum. The caecum is a small blind pouch like structure that opens into the colon and it possesses a narrow finger like tubular projection called vermiform appendix.

Both caecum and vermiform appendix are large in herbivorous animal and act as an important site for cellulose digestion with the help of symbiotic bacteria. The colon is divided into four regions – an ascending, a transverse, a descending part and a sigmoid colon.

The colon is lined by dilations called haustra (singular – haustrum) (Figure). The “S” shaped sigmoid colon (pelvic colon) opens into the rectum. Rectum is concerned with temporary storage of feces. The rectum open out through the anus. The anus is guarded by two anal sphincter muscles. The anal mucosa is folded into several vertical folds and contains arteries and veins called anal columns. Anal column may get enlarged and causes piles or haemorrhoids.

Question 20.
Explain the internal structure of the gut.
Answer:
The wall of the alimentary canal from oesophagus to rectum consists of four layers (Figure) namely serosa, muscularis, sub-mucosa and mucosa. The serosa (visceral peritoneum) is the outermost layer and is made up of thin squamous epithelium with some connective tissues. Muscularis is made of smooth circular and longitudinal muscle fibres with a network of nerve cells and parasympathetic nerve fibres which controls peristalsis.

The submucosal layer is formed of loose connective tissue containing nerves, blood, lymph vessels and the sympathetic nerve fibres that control the secretions of intestinal juice. The innermost layer lining the lumen of the alimentary canal is the mucosa which secretes mucous.

Question 21.
Explain the salivary glands.
Answer:
There are three pairs of salivary glands in the mouth. They are the largest parotids gland in the cheeks, the sub-maxillary sub-mandibular in the lower jaw and the sublingual beneath the tongue. These glands have ducts such as Stenson’s duct, Wharton’s duct and Bartholin’s duct or duct of Rivinis respectively (Figure). The salivary juice secreted by the salivary glands reaches the mouth through these ducts. The daily secretion of saliva from salivary glands ranges from 1000 to 1500 mL.

Question 22.
Write a short note on gastric glands.
Answer:
The wall of the stomach is lined by gastric glands. Chief cells or peptic cells or zymogen cells in the gastric glands secrete gastric enzymes and Goblet cells secrete mucus. The Parietal or oxyntic cells secrete HCl and an intrinsic factor responsible for the absorption of Vitamin B₁₂ called Castle’s intrinsic factor.

Question 23.
Explain the structure of liver.
Answer:
The liver, the largest gland in our body, is situated in the upper right side of the abdominal cavity, just below the diaphragm. The liver consists of two major left and right lobes; and two minor lobes. These lobes are connected with diaphragm. Each lobe has many hepatic lobules (functional unit of liver) and is covered by a thin connective tissue sheath called the Glisson’s capsule.

Liver cells (hepatic cells) secrete bile which is stored and concentrated in a thin muscular sac called the gall bladder. The duct of gall bladder (cystic duct) along with the hepatic duct from the liver forms the common bile duct.

The bile duct passes downwards and joins with the main pancreatic duct to form a common duct called hepato-pancreatic duct. The opening of the hepato-pancreatic duct into the duodenum is guarded by a sphincter called the sphincter of Oddi (Figure). Liver has high power of regeneration and liver cells are replaced by new ones every 3-4 weeks.

Question 24.
Write the functions of liver.
Answer:
Apart from bile secretion, the liver also performs several functions.

• Destroys aging and defective blood cells.
• Stores glucose in the form of glycogen or disperses glucose into the blood stream with the help of
• pancreatic hormones.
• Stores fat soluble vitamins and iron.
• Detoxifies toxic substances.
• Involves in the synthesis of non-essential amino acids and urea.

Question 25.
Write on the secretions of the pancreas.
Answer:
The second largest gland in the digestive system is the Pancreas, which is a yellow coloured, compound elongated organ consisting of exocrine and endocrine cells. It is situated between the limbs of the ‘U’ shaped duodenum.

The exocrine portion secretes pancreatic juice containing enzymes such as pancreatic amylase, trypsin and pancreatic lipase and the endocrine part called Islets of Langerhans secretes hormones such as insulin and glucagon. The pancreatic duct directly opens into the duodenum.

Question 26.
Explain the digestion in the buccal cavity.
Answer:
The smell, sight and taste as well as the mechanical stimulation of food in the mouth, triggers a reflex action which results in the secretion of saliva. The mechanical digestion starts in the mouth by grinding and chewing of food. It is called mastication.

The saliva contain water, electrolytes (Na⁺, K⁺, CL^– and HCO₃), salivary amylase (ptyalin), antibacterial agent lysozyme and a lubricating agent mucus (a glycoprotein). The mucus in saliva prepares the food for swallowing by moistening, softening, lubricating and adhering the masticated food into a bolus.

About 30 percent of polysaccharide, starch is hydrolyzed by the salivary amylase enzyme into disaccharides (maltose). The bolus is then passed into the pharynx and then into the oesophagus by swallowing or deglutition. The bolus further passes down through the oesophagus to the stomach by successive waves of muscular contraction called peristalsis. The gastro oesphageal sphincter controls the passage of food into the stomach.

Question 27.
Explain the digestion in the stomach.
Answer:
Food remains in the stomach for 4 to 5 hours, the rhythmic peristaltic movement chums and mixes the food with gastric juice and make it into a creamy liquid called chyme. The gastric secretion is partly controlled by autonomic reflexes.

The secretion of gastric juice begins when the food is in the mouth. The gastric juice contains HCl and proenzymes. The proenzyme pepsinogen, on exposure to HCl gets converted into the active enzyme pepsin which converts proteins into proteoses and peptones (peptides).

The HCl provides an acidic medium (pH 1.8) which is optimum for pepsin, kills bacteria and other harmful organisms and avoids putrifaction. The mucus and bicarbonates present in the gastric juice play an important role in lubrication and protection of the mucosal epithelium from the eroding nature of the highly acidic HCl (Figure). Another proteolytic enzyme found in gastric juice of infants is renin which helps in the digestion of milk protein, caseinogen to casein in the presence of calcium ions. This enzyme secretion gradually reduces with aging.

Question 28.
Explain the digestion in the small intestine.
Answer:
The bile, pancreatic juice and intestinal juice are the secretions released into the small intestine. Movements generated by the muscularis layer of the small intestine helps in the thorough mixing of the food with various secretions in the intestine and thereby facilitate digestion.

The pancreatic juice contains enzymes such as trypsinogen, chymotrypsinogen, carboxypeptidases, pancreatic amalyses, pancreatic lipases and nucleases. Trypsinogen is activated by an enzyme, enterokinase, secreted by the intestinal mucosa into active trypsin, which in turn activates the enzyme chymotrypsinogen in the pancreatic juice.

The bile contains bile pigments (bilirubin and biliverdin) as the break down products of hemoglobin of dead RBCs, bile salts, cholesterol and phospholipids but has no enzymes. Bile helps in emulsification of fats. Bile salts reduce the surface tension of fat droplets and break them into small globules. Bile also activates lipases to digest lipids.

Proteins and partially digested proteins in the chyme on reaching the intestine are acted upon by the proteolytic enzymes of pancreatic juice. Trypsin hydrolyses proteins into polypeptides and peptones, while chymotrypsin hydrolyses peptide bonds associated with specific amino acids. The pancreatic amylase converts glycogen and starch into maltose.

Lipase acts on emulsified fat (triglycerides) and hydrolyses them into free fatty acid and monoglycerides. Monoglycerides are further hydrolysed to fatty acid and glycerol. Nucleases in the pancreatic juice break the nucleic acid into nucleotides and nucleosides.

The secretions of the Brunner’s gland along with the secretions of the intestinal glands constitute the intestinal juice or succus entericus. The enzymes in the intestinal juice such as maltase, lactase, sucrase (invertase), dipeptidases, lipases, nucleosidases act on the breakdown products of bile and pancreatic digestion.

The mucus along with the bicarbonate ions from the pancreas provides an alkaline medium (pH 7.8) for the enzymatic action. As a result of digestion, all macromolecules of food are converted into their corresponding monomeric units.

Question 29.
Explain the process of absorption of the digested food.
Answer:
Absorption is a process by which the end product of digestion passes through the intestinal mucosa into the blood and lymph. The villi in the lumen of ileum are the absorbing units, consisting of a lacteal duct in the middle surrounded by fine network of blood capillaries. The process of absorption involves active, passive and facilitated transport.

Small amounts of glucose, amino acids and electrolytes like chloride ions are generally absorbed by simple diffusion. The passage of these substances into the blood depends upon concentration gradients. However, some of the substances like fructose are absorbed with the help of the carrier ions like Na⁺.

This mechanism is called facilitated transport. Nutrients like amino acids, glucose and electrolytes like Na⁺ are absorbed into the blood against the concentration gradient by active transport. The insoluble substances like fatty acids, glycerol and fat soluble vitamins are first incorporated into small, spherical water soluble droplets called micelles and are absorbed into the intestinal mucosa where they are re-synthesized into protein coated fat globules called chylomicrons which are then transported into the lacteals within the intestinal villi and eventually empty into lymphatic duct.

The lymphatic ducts ultimately release the absorbed substances into the blood stream. While the fatty acids are absorbed by the lymph duct, other materials are absorbed either actively or passively by the capillaries of the villi (Figure). Water soluble vitamins are absorbed by simple diffusion or active transport. Transport of water depends upon the osmotic gradient. Absorption of substances in the alimentary canal takes place in mouth, stomach, small intestine and large intestine.

However maximum absorption takes place in the small intestine. Absorption of simple sugars, alcohol and medicines takes place in the stomach. Certain drugs are absorbed by blood capillaries in the lower side of the tongue and mucosa of mouth. Large intestine is also involved in absorption of more amounts of water, vitamins, some minerals and certain drugs.

Question 30.
Write a note on assimilation.
Answer:
Absorbed substances are transported through blood and lymph to the liver through the hepatic portal system. From the liver, nutrients are transported to all other regions of the body for utilization. All the body tissues utilize the absorbed substance for their activities and incorporate into their protoplasm, this process is called assimilation.

Question 31.
Write a paragraph on egestion.
Answer:
The digestive waste and unabsorbed substances in the ileum enter into the large intestine and it mostly contains fibre called roughage. The roughage is utilized by symbiotic bacteria in the large intestine for the production of substances like vitamin K and other metabolites. All these substances are absorbed in the colon along with water.

The waste is then solidified into fecal matter in the rectum. The fecal matter initiates a neural reflex causing an urge or desire for its removal. The egestion of feces through the anal opening is called defecation. It is a voluntary process and is carried out by a peristaltic movement.

Question 32.
Write on carbohydrates and lipids.
Answer:
Carbohydrates are sugar and starch. These are the major source of cellular fuel which provides energy. The caloric value of carbohydrate is 4.1 calories per gram and its physiological fuel value is 4 Kcal per gram. Lipids are fats and derivatives of fats, are also the best reserved food stored in our body which is used for production of energy. Fat has a caloric value of 9.45 Kcal and a physiological fuel value of 9 Kcal per gram.

Question 33.
Write a paragraph on proteins.
Answer:
Proteins are source of amino acids required for growth and repair of body cells. They are stored in the body only to a certain extent; large quantities are excreted as nitrogenous waste. The caloric value and physiological fuel value of one gram of protein are 5.65 Kcal and 4 Kcal respectively. According to ICMR (Indian Council of Medical Research) and WHO (World Health Organization), the daily requirement of protein for an average Indian is 1 gm per 1 kg body weight.

Question 34.
Explain the protein deficiency diseases.
Answer:
Growing children require more amount of protein for their growth and development. Protein deficient diet during early stage of children may lead to protein energy malnutrition such as Marasmus and Kwashiorkor. Symptoms are dry skin, pot-belly, oedema in the legs and face, stunted growth, changes in hair colour, weakness and irritability.

Marasmus is an acute form of protein malnutrition. This condition is due to a diet with inadequate carbohydrate and protein. Such children are suffer from diarrhoea, body becomes lean and weak (emaciated) with reduced fat and muscle tissue with thin and folded skin.

Question 35.
What is indigestion?
Answer:
It is a digestive disorder in which the food is not properly digested leading to a feeling of fullness of stomach. It may be due to inadequate enzyme secretion, anxiety, food poisoning, over eating and spicy food.

Question 36.
What is constipation?
Answer:
In this condition, the feces are retained within the rectum because of irregular bowel movement due to poor intake of fibre in the diet and lack of physical activities.

Question 37.
What is vomiting?
Answer:
It is reverse peristalsis. Harmful substances and contaminated food from stomach are ejected through the mouth. This action is controlled by the vomit center located in the medulla oblongata. A feeling of nausea precedes vomiting.

Question 38.
Write a short note on jaundice.
Answer:
It is the condition in which liver is affected and the defective liver fails to break down haemoglobin and to remove bile pigments from the blood. Deposition of these pigments changes the colour of eye and skin yellow. Sometimes, jaundice is caused due to hepatitis viral infections.

Question 39.
Write a short note on liver cirrhosis.
Answer:
Chronic disease of liver results in degeneration and destruction of liver cells resulting in abnormal blood vessel and bile duct leading to the formation of fibrosis. It is also called deserted liver or scarred liver. It is caused due to infection, consumption of poison, malnutrition and alcoholism.

Question 40.
Write a short note on gall stones.
Answer:
Any alteration in the composition of the bile can cause the formation of stones in the gall bladder. The stones are mostly formed of crystallized cholesterol in the bile. The gall stone causes obstruction in the cystic duct, hepatic duct and also hepato-pancreatic duct causing pain, jaundice and pancreatitis.

Question 41.
What is appendicitis?
Answer:
It is the inflammation of the vermiform appendix, leading to severe abdominal pain. The treatment involves the removal of appendix by surgery. If treatment is delayed the appendix may rupture and results in infection of the abdomen, called peritonitis.

Question 42.
What is hiatus hernia or diaphragmatic hernia?
Answer:
It is a structural abnormality in which superior part of the stomach protrudes slightly above the diaphragm. The exact cause of hiatus hernias is not known. In some people, injury or other damage may weaken muscle tissue, by applying too much pressure (repeatedly) on the muscles around the stomach while coughing, vomiting, and straining during bowel movement and lifting heavy object.

Heart bum is also common in those with a hiatus hernia. In this condition, stomach contents travel back into the oesophagus or even into oral cavity and causes pain in the center of the chest due to the eroding nature of acidity.

Question 43.
Write a short note on diarrhoea.
Answer:
It is the most common gastrointestinal disorder worldwide. It is sometimes caused by bacteria or viral infections through food or water. When the colon is infected, the lining of the intestine is damaged by the pathogens, thereby the colon is unable to absorb fluid.

The abnormal frequency of bowel movement and increased liquidity of the fecal discharge is known as diarrhoea. Unless the condition is treated, dehydration can occur. Treatment is known as oral hydration therapy. This involves drinking plenty of fluids – sipping small amounts of water at a time to rehydrate the body.

Question 44.
Write a paragraph on peptic ulcer.
Answer:
It refers to an eroded area of the tissue lining (mucosa) in the stomach or duodenum. Duodenal ulcer occurs in people in the age group of 25 – 45 years. Gastric ulcer is more common in persons above the age of 50 years. Ulcer is mostly due to infections caused by the bacterium Helicobacter pylori. It may also be caused due to uncontrolled usage of aspirin or certain anti-inflammatory drugs. Ulcer may also be caused due to smoking, alcohol, caffeine and psychological stress.

Question 45.
What is obesity?
Answer:
It is caused due to the storage of excess of body fat in adipose tissue. It may induce hypertension, atherosclerotic heart disease and diabetes. Obesity may be genetic or due to excess intake of food, endocrine and metabolic disorders.

Question 46.
Write a note on BMI.
Answer:
Degree of obesity is assessed by body mass index (BMI). A normal BMI range for adult is 19 – 25; above 25 is considered as obese. BMI is calculated as body weight in Kg, divided by the square of body height in meters. For example, a 50 Kg person with a height of 160 cms would have a BMI of 19.5.
That is BMI = 50 / 1.62= 19.5

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Samacheer Kalvi 11th Bio Botany Taxonomy and Systematic Botany Text Book Back Questions and Answers

I. Multiple Choice Questions
Choose the correct answer
Question 1.
Specimen derived from non – original collection serves as the nomenclatural type, when original specimen is missing. It is known as …………… .
(a) Holotype
(b) Neotype
(c) Isotype
(d) Paratype
Answer:
(b) Neotype

Question 2.
Phylogenetic classification is the most favoured classification because it reflects …………… .
(a) Comparative Anatomy
(b) Number of flowers produced
(c) Comparative cytology
(d) Evolutionary relationships
Answer:
(d) Evolutionary relationships

Question 3.
The taxonomy which involves the similarities and dissimilarities among the immune system of different taxa is termed as …………… .
(a) Chemotaxonomy
(b) Molecular systematics
(c) Serotaxonomy
(d) Numerical taxonomy
Answer:
(c) Serotaxonomy

Question 4.
Which of the following is a flowering plant with nodules containing filamentous nitrogen – fixing micro – organisms?
(a) Crotalaria juncea
(b) Cycas revoluta
(c) Cicer arietinum
(d) Casuarina equisetifolia
Answer:
(a) Crotalaria juncea

Question 5.
Flowers are zygomorphic in …………… .
(a) Ceropegia
(b) Thevetia
(c) Datura
(d) Solarium
Answer:
(a) Ceropegia

Question 6.
What is the role of national gardens in conserving biodiversity – discuss.
Answer:
Botanical Gardens plays the following important roles.

1. Gardens with aesthetic value which attract a large number of visitors. For example, the Great Banyan Tree (Ficus benghalensis) in the Indian Botanical Garden at Kolkata
2. Gardens have a wide range of species and supply taxonomic material for botanical research.
3. Garden is used for self-instruction or demonstration purposes.

Question 7.
Where will you place the plants which contain two cotyledons with cup shaped thalamus?
Answer:
The plants which contain two cotyledons with cup shaped thalamus:

• Class: Dicotyledonae
• Subclass: Polypetalae
• Series: Calyciflorae

Question 8.
How does molecular markers work to unlock the evolutionary history of organisms?
Answer:
Molecular taxonomy using molecular markers like RAPD’s etc, helps in establishing the relationship between the members of different taxonomic groups at DNA level. Thus it helps to unlock the evolutionary history of  organisms.

Question 9.
Give the floral characters of Clitoria ternatea.
Answer:
Flower: Bracteate, bracteolate, bracteoles usually large, pedicellate, heterochlamydeous, complete, bisexual, pentamerous, zygomorphic and hypogynous.

Question 10.
How will you distinguish Solanaceae members from Liliaceae members?
Answer:

Characters	Solanaceae members	Liliaceae members
Root	Branched taproot	Adventitious fibrous root
Stem	Herbaceous	bulbous / rhizomatous
Leaf	Reticulate venation	Parallel venation
Inflorescence	Solitary and axillary cyme	Simple or branched raceme
Flowers	pentamerous	Trimerous
Androecium	Stamens 5, epipetalous	Stamens 6, epiphyllous
Gynoecium	Bicarpellary	Tricarpellary

Textbook Activities Solved

Question 1.
Write common name and scientific name of 10 different plants around your home.
Answer:

Common name of plants	Scientific name of plants
1. Mango	1. Mangifera indica
2. Banana	2. Musa paradisiaca
3. Shoe flower	3. Hibiscus rosa – sinensis
4. Neem	4. Azadirachta indica
5. Coconut	5. Cocus nucifera
6. Rice	6. Oryza sativa
7. Onion	7. Allium cepa
8. Tomato	8. Solanum lycopersicum
9. Carrot	9. Dacus carota
10. Brinjal	10. Solanum melongena

Question 2.
Can you identify this?

(a) Name the family
(b) Write the binomial
(c) List the economic uses
Answer:
(a) Liliaceae family
(b) Aloe vera
(c) List the economic uses:

• The gel – like part of Aloe vera contain proteole enzymes which repairs and rejunuveates the skin.
• It acts as a great conditioner for hair.
• Aloe juice acts as coolant and soothes gastric problems like ulcer.

Entrance Examination Questions Solved

Choose the correct answer:
Question 1.
Leaves become modified into spines in …………… . [AIPMT – 2015]
(a) Silk Cotton
(b) Opuntia
(c) Pea
(d) Onion
Answer:
(b) Opuntia

Question 2.
Keel is the characteristic feature of flower of …………… . [AIPMT – 2015]
(a) Tomato
(b) Tulip
(c) Indigofera
(d) Aloe
Answer:
(c) Indigofera

Question 3.
Perigynous flowers are found in …………… .[AIPMT – 2015]
(a) Rose
(b) Guava
(c) Cucumber
(d) China rose
Answer:
(a) Rose

Question 4.
Which one of the following statements is correct? [AIPMT – 2014]
(a) The seed in grasses is not endospermic
(b) Mango is a parthenocarpic fruit
(c) A proteinaceous aleurone layer is present in maize grain
(d) A sterile pistil is called a staminode
Answer:
(c) A proteinaceous aleurone layer is present in maize grain

Question 5.
An example of edible underground stem is …………… . [AIPMT – 2014]
(a) Carrot
(b) Groundnut
(c) Sweet potato
(d) Potato
Answer:
(d) Potato

Question 6.
Placenta and pericarp are both edible portions in …………… . [AIPMT – 2014]
(a) Apple
(b) Banana
(c) Tomato
(d) Potato
Answer:
(c) Tomato

Question 7.
When the margins of sepals or petals overlap one another without any particular direction, the condition is termed as …………… . [AIPMT – 2014]
(a) Vexillary
(b) Imbricate
(c) Twisted
(d) Valvate
Answer:
(b) Imbricate

Question 8.
An aggregate fruit is one which develops from …………… . [AIPMT – 2014]
(a) Multicarpellary syncarpous gynoecium
(b) Multicarpellary apocarpous gynoecium
(c) Complete inflorescence
(d) Multicarpellary superior ovary
Answer:
(b) Multicarpellary apocarpous gynoecium

Question 9.
Non – albuminous seed is produced in …………… .
(a) Maize
(b) Castor
(c) Wheat
(d) Pea
Answer:
(d) Pea

Question 10.
Seed coat is not thin, membranous in …………… .
(a) Coconut
(b) Groundnut
(c) Gram
(d) Maize
Answer:
(a) Coconut

Question 11.
In china rose the flower are …………… .
(a) Actinomorphic,. Epigynous with valvate aestivation
(b) Zygomorphic, hypogynous with imbricate aestivation
(c) Zygomorphic, epigynous with twisted aestivation
(d) Actinomorphic, hypogynous with twisted aestivation
Answer:
(d) Actinomorphic, hypogynous with twisted aestivation

Question 12.
Placentation in tomato and lemon is …………… .
(a) Marginal
(b) Axile
(c) Parietal
(d) Free central
Answer:
(b) Axile

Question 13.
Vexillary aestivation is characteristic of the family …………… .
(a) Solanaceae
(b) Brassicaceae
(c) Fabaceae
(d) Asteraceae
Answer:
(c) Fabaceae

Question 14.
Phyllode is present in …………… . [AIPMT Prelims – 2012]
(a) Australian Acacia
(b) Opuntia
(c) Asparagus
(d) Euphorbia
Answer:
(c) Asparagus

Question 15.
How many plants in the list given below have composite fruits that develop from an inflorescence? Walnut, poppy, radish,pineapple, apple, tomato …………… . [AIPMT Prelims – 2012]
(a) Two
(b) Three
(c) Four
(d) Five
Answer:
(a) Two

Question 16.
Cymose inflorescence is present in …………… . [AIPMT Prelims – 2012]
(a) Trifolium
(b) Brassica
(c) Solanum
(d) Sesbania
Answer:
(b) Brassica

Question 17.
Which one of the following organism is correctly matched with its three characteristics? [AIPMT Mains – 2012]
(a) Pea : C₃ pathway, Endospermic seed,Vexillary aestivation
(b) Tomato : Twisted aestivation, Axile placentation, Berry
(c) Onion : Bulb, Imbricate aestivation, Axile placentation
(d) Maize : C₃ pathway, Closed vascular bundles, scutellum
Answer:
(c) Onion : Bulb, Imbricate aestivation, Axile placentation

Question 18.
How many plants in the list given below have marginal placentation? Mustard, Gram, Tulip, Asparagus, Arhar,sun hemp, Chilli, Colchicine, Onion,Moong, Pea, Tobacco, Lupin …………… . [AIPMT Mains – 2012]
(a) Four
(b) Five
(c) Six
(d) Three
Answer:
(c) Six

Question 19.
The Eyes of the potato tuber are …………… . [AIPMT Prelims – 2011]
(a) Axillary buds
(b) Root buds
(c) Flower buds
(d) Shoot buds
Answer:
(a) Axillary buds

Question 20.
Which one of the following statements is correct? [AIPMT Prelims – 2011]
(a) Flower of tulip is a modified shoot
(b) In tomato, fruit is a capsule
(c) Seeds of orchids have oil – rich endosperm
(d) Placentation in primrose is basal
Answer:
(d) Placentation in primrose is basal

Question 21.
A drup develops in …………… . [AIPMT Prelims-2011]
(a) Tomato
(b) Mango
(c) Wheat
(d) Pea
Answer:
(b) Mango

Samacheer Kalvi 11th Bio Botany Taxonomy and Systematic Botany Additional Questions and Answers

I. Multiple Choice Questions
Choose the correct answer:
Question 1.
Who is called as the father of Botany?
(a) Linnaeus
(b) Theophrastus
(c) Darwin
(d) Thales
Answer:
(b) Theophrastus

Question 2.
…………… is the lowest level of classification.
(a) Kingdom
(b) Class
(c) Order
(d) Species
Answer:
(d) Species

Question 3.
Who proposed the concept of “idos” or species?
(a) Theophrastus
(b) Stebbians
(c) Darwin
(d) Plato
Answer:
(d) Plato

Question 4.
Which type of species develop by the process of evolution?
(a) Taxonomic species
(b) Morphological species
(c) Biological species
(d) Phylogenetic species
Answer:
(c) Biological species

Question 5.
Who first proposed the early elementary rule of naming plants?
(a) A.P.de Candolle
(b) Linnaeus
(c) Alphonse de Candolle
(d) Simpson
Answer:
(b) Linnaeus

Question 6.
Isolation species can also be called as …………… Species.
(a) Biological
(b) Taxonomical
(c) Phylogenetic
(d) Morphological
Answer:
(a) Biological

Question 7.
18^th International Botanical congress was held at …………… .
(a) Sydney
(b) Leningard
(c) Melbourne
(d) London
Answer:
(c) Melbourne

Question 8.
In 2017, …………… International Botanical congress was held at Shenzhen.
(a) 17^th
(b) 18^th
(c) 19^th
(d) 20^th
Answer:
(c) 19^th

Question 9.
The vernacular name of Albizia amara in South Tamilnadu is …………… .
(a) Thurinji
(b) Kurinji
(c) Nithyakalyani
(d) Usilai
Answer:
(d) Usilai

Question 10.
…………… is a descriptive phrase of a plant.
(a) Vernacular name
(b) Binomial
(c) Polynomial
(d) Botanical name
Answer:
(c) Polynomial

Question 11.
…………… introduced the concept of Binomial nomenclature.
(a) Linnaeus
(b) Gaspard Bauhin
(c) Darwin
(d) Wallace
Answer:
(b) Gaspard Bauhin

Question 12.
Duplicate specimen of holotype is …………… .
(a) Lectotype
(b) Isotype
(c) Neotype
(d) Syntype
Answer:
(b) Isotype

Question 13.
…………… are the tools for identifying unfamiliar plants.
(a) Flora
(b) Keys
(c) Monograph
(d) Catalogues
Answer:
(b) Keys

Question 14.
…………… is a complete global account of a taxon of any rank.
(a) Flora
(b) Keys
(c) Monograph
(d) Catalogues
Answer:
(c) Monograph

Question 15.
The first botanical garden was established and maintained by …………… .
(a) Linnaeus
(b) Babylonians
(c) Theophrastus
(d) Stebbins
Answer:
(c) Theophrastus

Question 16.
First modern botanical garden was established by …………… .
(a) Theophrastus
(b) Linnaeus
(c) Luca Ghini
(d) Stebbins
Answer:
(c) Luca Ghini

Question 17.
…………… is the largest botanical garden in world.
(a) Royal Botanical garden
(b) Madras Presidency College
(c) Indian Botanical Garden
(d) New York Botanical garden
Answer:
(a) Royal Botanical garden

Question 18.
Who is called as father of taxonomy?
(a) Engler & Prantl
(b) Linnaeus
(c) Theophrastus
(d) Darwin
Answer:
(b) Linnaeus

Question 19.
Number of stamen(s) in monandria is …………… .
(a) 4
(b) 3
(c) 2
(d) 1
Answer:
(d) 1

Question 20.
Sexual system of classification is also called as …………… .
(a) Natural system
(b) Artificial system
(c) Phylogenetic
(d) APG system
Answer:
(b) Artificial system

Question 21.
Number of series under Polypetalae.
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(c) 3

Question 22.
Which series includes epigynous flowers with inferior ovary?
(a) Heteromerae
(b) Disaflorea
(c) Inferae
(d) Thalanifloreae
Answer:
(c) Inferae

Question 23.
Undistinguished sepal and petal is called as …………… .
(a) Petaloid
(b) Staminode
(c) Perianth
(d) Sepaloid
Answer:
(c) Perianth

Question 24.
Which is not a family of gymnospermae?
(a) Gnetaceae
(b) Equistae
(c) Coniferae
(d) Cycadaceae
Answer:
(b) Equistae

Question 25.
Which is not a monocotyledon character?
(a) One cotyledon
(b) Parallel venation
(c) Pentamerous
d) Fibrous root
Answer:
(c) Pentamerous

Question 26.
Number of divisions in Engler and Prantl classification?
(a) 10
(b) 11
(c) 12
(d) 13
Answer:
(d) 13

Question 27.
“The evolution and classification of flowering plants” – book was written by …………… .
(a) Engler & Prantl
(b) Bentham & Hooker
(c) Cronquist
(d) Theophrasthus
Answer:
(c) Cronquist

Question 28.
Which of the following is not a clade of APG – classification?
(a) Early angiosperm
(b) Early gymnosperm
(c) Monocots
(d) Eudicots
Answer:
(b) Early gymnosperm

Question 29.
The term biosystematics was introduced by …………… .
(a) Bauhin
(b) Camp & Gilly
(c) Cronquist
(d) Smith
Answer:
(b) Camp & Gilly

Question 30.
Taxonomy based on chromosomal number & characteristics is called …………… .
(a) Serotaxonomy
(b) Cytotaxonomy
(c) Chemotaxonomy
(d) Molecular taxonomy
Answer:
(b) Cytotaxonomy

Question 31.
Classification based on protein content is called …………… .
(a) Serotaxonomy
(b) Cytotaxonomy
(c) Chemotaxonomy
(d) Molecular taxonomy
Answer:
(a) Serotaxonomy

Question 32.
DNA bar coding was introduced by …………… .
(a) Stebbins
(b) Hebert
(c) Camp & Gilly
(d) Darwin
Answer:
(b) Hebert

Question 33.
Biosystematics is also called as …………… .
(a) α – taxonomy
(b) S – taxonomy
(c) Ω – taxonomy
(d) β – taxonomy
Answer:
(c) Ω – taxonomy

Question 34.
Outcome of cladistics analysis is …………… .
(a) Monogram
(b) Monograph
(c) Cladogram
(d) Cladograph
Answer:
(c) Cladogram

Question 35.
Taxa comprising all the descendents of a common ancestor.
(a) Monophyletic group
(b) Diphyletic group
(c) Paraphyletic group
(d) Polyphyletic group
Answer:
(a) Monophyletic group

Question 36.
Papilionaceous corolla is seen in …………… family.
(a) Apocyanaceae
(b) Fabaceae
(c) Solanaceae
(d) Liliaceae
Answer:
(b) Fabaceae

Question 37.
Stipitate ovary is seen in …………… .
(a) Solanaceae
(b) Liliaceae
(c) Fabaceae
(d) Apocyanaceae
Answer:
(a) Solanaceae

Question 38.
Number of genus in fabaceae is …………… .
(a) about 131
(b) about 741
(c) about 751
(d) about 761
Answer:
(b) About 741

Question 39.
The characteristic fruit of fabaceae is …………… .
(a) Regima
(b) Legume
(c) Hespiridium
(d) Berry
Answer:
(b) Legume

Question 40.
In Arachis hypogea, the fruit development is …………… .
(a) Syncarpic
(b) Apocarpic
(c) Geocarpic
(d) Photocarpic
Answer:
(c) Geocarpic

Question 41.
Which of the following plants root is a Immunomodulator?
(a) Glycirrhiza glabra
(b) Dalbergia latifolia
(c) Mucum pruriens
(d) Crotolaria jurcea
Answer:
(a) Glycirrhiza glabra

Question 42.
Indigo dye is obtained from plant.
(a) Lupin
(b) Avuri
(c) Sesban
(d) Agathi
Answer:
(b) Avuri

Question 43.
Which plant is commonly called as the “Flame of the forest”?
(a) Clitoritematea
(b) Butea frondosa
(c) Lupinus hirsutus
(d) Butea monosperma
Answer:
(b) Butea frondosa

Question 44.
Which year is declared as the “International year of the pulses”.
(a) 2017
(b) 2018
(c) 2015
(d) 2016
Answer:
(d) 2016

Question 45.
Which is called as “Night Shade family”?
(a) Solanaceae
(b) Fabaceae
(c) Apocyanaceae
(d) Liliaceae
Answer:
(a) Solanaceae

Question 46.
Rhiphidium inflorescence is seen in …………… .
(a) Solanum nigrum
(b) Solanum tuberosum
(c) Datura
(d) Withania somnifera
Answer:
(a) Solatium nigrum

Question 47.
The fruit of Datura metal is …………… .
(a) Spinescent Capsule
(b) Regma
(c) Legume
(d) Capsule
Answer:
(a) Spinescent capsule

Question 48.
Plicate inflorescence is seen in …………… .
(a) Solanum nigrum
(b) Datura metal
(c) Petunia hybrida
(d) Solanum tuberosum
Answer:
(b) Datura metal

Question 49.
…………… drug is used to treat asthma & whooping cough.
(a) Atropine
(b) Stramonium
(c) Anabasine
(d) Normicotine
Answer:
(b) Stramonium

Question 50.
Inflorescence in Aloe is …………… .
(a) Compound Spadix
(b) Spike
(c) Paricle
(d) Solitary
Answer:
(b) Spike

Question 51.
Carpels are obliquely placed in …………… .
(a) Fabaceae
(b) Solanaceae
(c) Liliaceae
(d) Apocyanaeae
Answer:
(b) Solanaceae

Question 52.
Septal glands are present in the gynoeciums of …………… .
(a) Solanaceae
(b) Liliaceae
(c) Fabaceae
(d) Apocyanaeae
Answer:
(b) Liliaceae

Question 53.
…………… is an alkaloid that induces polyploidy.
(a) Nictonine
(b) Stramonium
(c) Atropine
(d) Colchicine
Answer:
(d) Colchicine

Question 54.
The leaves of …………… is used in hemorrhoidal salves & shampoos.
(a) Aloe barbadense
(b) Aloevera
(c) Allium sativum
(d) Allium cepa
Answer:
(b) Aloevera

Question 55.
Botanical survey of India has …………… regional centres in India.
(a) 10
(b) 11
(c) 12
(d) 13
Answer:
(b) 11

Question 56.
Synstamenous condition is seen in …………… .
(a) Haemodorum
(b) Ruscus
(c) Paris quadrfolia
(d) Maianthenum
Answer:
(b) Ruscus

Question 57.
Scapigerous inflorescence is seen in …………… .
(a) Allium sativum
(b) Allium cepa
(c) Aloevera
(d) Maenodorum
Answer:
(b) Allium cepa

Question 58.
Number of stamens in Schizanthus is …………… .
(a) 2
(b) 3
(c) 4
(d) 5
Answer:
(a) 2

Question 59.
Extra axillary scorpiod cyme is called …………… .
(a) Spike
(b) Monochasical cyme
(c) Helicoid cyme
(d) Rhiphidium
Answer:
(d) Rhiphidium

II. Very Short Answer Type Questions (2 Marks)

Question 1.
Define Taxonomy.
Answer:
Taxonomy is “the science dealing with the study of classification including the bases, principles, rules and procedures”.

Question 2.
List out the various rank or taxa of taxonomic hierarchy.
Answer:
Kingdom, Phylum, Class, Order, Family, Genus, Species

Question 3.
Which is the lowest taxon in classification? Define.
Answer:
Species is the lowest taxon in classification. It is defined as the group of individuals which are closely resembling each other and interbreed among themselves producing fertile offspring.

Question 4.
Define Nomenclature.
Answer:
Assigning name for a plant is known as Nomenclature.

Question 5.
What are vernacular names? Give an example.
Answer:
Vernacular names are known as common names. Example: Albizia amara L. is called as Usilai in South Tamil Nadu and Thurinji in North Tamil Nadu.

Question 6.
What is Author citation?
Answer:
Author citation refers to valid name of the taxa accompanied by the author’s name who published the name validly. Example: Solanum nigrum L.

Question 7.
Define e – Flora.
Answer:
Electronic Floras (e – floras) is the digitized form of a flora published online.
Example: e – Flora China. This provides the information and also functions as an identification tool.

Question 8.
When a neotype specimen is selected?
Answer:
Neotype Specimen is derived from non – original collection selected as the type, when original specimen is missing or destroyed.

Question 9.
What do you mean by taxonomical aids?
Answer:
Tools, techniques, procedures and stored information that are useful in identification and classification of organisms are called taxonomical aids.

Question 10.
Differentiate Regional Flora from continental flora.
Answer:
Regional Flora from continental flora.

1. Regional Flora: Flora covering a large geographical area or a botanical region Ex: flora of Madras Presidency.
2. Continental Flora: Flora covering the entire continent. Ex: flora of Europaea.

Question 11.
What is Herbarium specimen?
Answer:
Herbarium Specimen is defined as a pressed and dried plant sample that is permanently glued or strapped to a sheet of paper along with a documentation label.

Question 12.
Name the major classes of Bentham & Hooker Classification.
Answer:
The major classes of Bentham & Hooker Classification:

• Class 1 – Dicotyledonae
• Class 2 – Gymnospermae
• Class 3 – Monocotyledonae

Question 13.
How Cronquist classified the angiosperms?
Answer:
Cronquist classified the angiosperms into two main classes Magnoliopsida and Liliopsida.

Question 14.
Cronquist classification is a failure. Justify.
Answer:
Cronquist classification system is not very useful for identification and cannot be adopted in herbaria due to its high phylogenetic nature.

Question 15.
Which is the most recent classification of flowering plants? How many versions it had been published so far?
Answer:
Angiosperm phylogeny group classification (APG) is the recent classification of flowering plants. APG I, APG II, APG III, APG IV are the four versions.

Question 16.
Name any 4 sub classes of Liliopsida.
Answer:
4 sub classes of Liliopsid:

1. Alismatidae
2. Arecidae
3. Commelinidae
4. Zingiberidae

Question 17.
Why the classification undergoes changes very often?
Answer:
Classification reflects the state of our knowledge at a given point of time. It will continue to change as we acquire new information.

Question 18.
Point out the aims of chemotaxonomy.
Answer:
The aims of chemotaxonomy:

1. To develop taxonomic characters which may improve existing system of plant classification.
2. To improve present day knowledge of phylogeny of plants.

Question 19.
Define Biosystematics.
Answer:
Biosystematics is an “Experimental, ecological and cytotaxonomy” through which life forms are studied and their relationships are defined.

Question 20.
Name few molecular markers used in molecular taxonomy.
Answer:
Allozymes, mitochondrial DNA, micro satellites, RFLP (Restriction Fragment Length Polymorphism), RAPD (Random amplified polymorphic DNA), AFLPs (Amplified Fragment Length Polymorphism), Single nucleotide Polymorphism – SNP, microchips or arrays.

Question 21.
List out the significance of DNA bar coding?
Answer:
The significance of DNA bar coding:

1. DNA bar coding greatly helps in identification and classification of organism.
2. It aids in mapping the extent of biodiversity.

Question 22.
State the demerits of RAPD analysis.
Answer:
RAPD analysis has the major disadvantage that results are difficult to replicate and in the homology of similar bands in different taxa may be nuclear.

Question 23.
Define Cladistics.
Answer:
The method of classifying organisms into monophyletic group of a common ancestor based on shared apomorphic characters is called Cladistics.

Question 24.
Define Cladogram.
Answer:
The outcome of a cladistic analysis is a cladogram, a tree – shaped diagram that represent the best hypothesis of phylogenetic relationships.

Question 25.
The genetic sequence used to identify a plant is known as “DNA tags” or “DNA barcodes”.
Answer:
The system of naming the organism with two names, generic name and specific (species)
name is known as binomial system of nomenclature, e.g. Pavo cistatus – Indian pea fowl.

Question 26.
Compare the Gynoecium of Pisum sativum and Datura metal.
Answer:
Gynoecium of Pisum sativum:

1. Mono Carpellary
2. Unilocular
3. Ovules on marginal placentation
4. Feathery stigma

Gynoecium of Datura metal:

1. Bicarpellary
2. Tetralocular
3. Ovules on axile placentation
4. Bilobed stigma

Question 27.
Write the floral formula of Pisum sativum.
Answer:

Question 28.
Name binomial name of any two oil plants of Fabaceae.
Answer:
Two oil plants of Fabaceae:

1. Arachis hypogea (Ground nut) and
2. Pongamia pinnata (Pungam).

Question 29.
Explain the classical taxonomical tools.
Answer:
Extra axillary scorpiod cyme is called rhiphidium.

Question 30.
Name the type of fruit seen in Capsicum and Datura.
Answer:
The type of fruit seen in Capsicum and Datura:

1. Capsicum – Berry
2. Datura – Capsule

Question 31.
What is atropine?
Answer:
Atropine is a powerful alkaloid obtained from Atropa belladonna root is used in belladonna plasters, tinctures etc, for relieving pain and also for dilating pupils of eyes for eye – testing.

Question 32.
What is Stramonium?
Answer:
Stramonium is a drug obtained from the leaves and roots of Datura stramonium and used to treat asthma and whooping cough.

Question 33.
Which stimulated Engler and Prantl to prepare phylogenic classification?
Answer:
The publication of the Origin of Species (1859) by Charles Darwin has given stimulus for the emergence of phylogenetic system of classification.

III. Short Answer Type Questions (3 Marks)

Question 1.
How dichotomous key helps in identification of plants?
Answer:
Dichotomous key consists of a sequence of two contrasting statements. A pair of contrasting statements is known as couplet. Each statement is known as lead. The plant is correctly identified with keys by narrowing down the characters found in plant.

Question 2.
Differentiate between Taxonomy & Systematics.
Answer:
Taxonomy:

1. Discipline of classifying organisms into taxa
2. Governs the practices of naming, describing, identifying and specimen preservation.
3. Classification + Nomenclature = Taxonomy

Systematics:

1. Broad field of biology that studies the diversification of species
2. Governs the evolutionary history and phylogenetic relationship in addition to taxonomy
3. Taxonomy + Phylogeny = Systematics

Question 3.
Write a note on Binomial nomenclature.
Answer:
binomial nomenclature, the first one is called genus name and second one is specific epithet. Example: Mangifera indica, Mangifera is a genus name and indica is specific epithet.

Question 4.
Enumerate the steps involved in herbarium preparation.
Answer:
Preparation of herbarium specimen includes the following steps.

1. Plant Collection
2. Documentation of field site data
3. Preparation of plant specimen
4. Mounting herbarium specimen
5. Herbarium labels
6. Protection of herbarium sheets against mold and insects

Question 5.
Why do we need the classification of organisms?
Answer:
The classification of organisms:

1. Understanding the classification of organisms can gives an insight into other fields and has significant practical value.
2. Classification helps us to know about different taxa, their phylogenetic relationship and exact position.
3. It helps to train the students of plant sciences with regard to the diversity of organisms and their relationship with other biological branches.

Question 6.
Classification is a essential part of biology – Justify.
Answer:
Classification is essential to biology because there is a vast diversity of organisms to sort out and compare. Unless they are organized into manageable categories it will be difficult for identification.

Question 7.
Linnaeus classification is also called sexual system of classification. Why?
Answer:
Linnaeus classification is mostly based on sexual characters like number, union, length and distribution of stamens and also on carpel characters. Hence it is called sexual system of classification.

Question 8.
Write a note on Monochlamydeae.
Answer:
Plants with incomplete flowers either apetalous or with undifferentiated calyx and corolla are placed under Monochlamydeae. The sepals and petals are not distinguished and they are called perianth. Sometimes both the whorls are absent. Monochlamydeae includes 8 series and 36 families.

Question 9.
In chemotaxonomy, how the chemicals are categorised?
Answer:
The chemical characters can be divided into three main categories:

1. Easily visible characters like starch grains, silica etc.
2. Characters detected by chemical tests like phenolics, oil, fats, waxes etc.
3. Proteins

Question 10.
Define Serotaxonomy.
Answer:
The classification of very similar plants by means of differences in the proteins they contain, to solve taxonomic problems is called serotaxonomy.

Question 11.
What is Molecular taxonomy?
Answer:
Molecular Taxonomy is the branch of phylogeny that analyses hereditary molecular differences, mainly in DNA sequences, to gain information and to establish genetic relationship between the members of different taxonomic categories.

Question 12.
Point out the uses of molecular taxonomy.
Answer:
The uses of molecular taxonomy:

1. Molecular taxonomy helps in establishing the relationship of different plant groups at DNA level.
2. It unlocks the treasure chest of information on evolutionary history of organisms.

Question 13.
How RFLP helps in taxonomical studies?
Answer:
RFLP (Restriction Fragment Length Polymorphism): RFLP’s is a molecular method of genetic analysis that allows identification of taxa based on unique patterns of restriction sites in specific regions of DNA. It refers to differences between taxa in restriction sites and therefore the lengths of fragments of DNA following cleavage with restriction enzymes.

Question 14.
Define DNA barcoding.
Answer:
DNA barcoding is a taxonomic method that uses a very short genetic sequence from a standard part of a genome. The genetic sequence used to identify a plant is known as “DNA tags” or “DNA barcodes”. Paul Hebert in 2003 proposed “DNA barcoding” and he is considered as ‘Father of barcoding’.

Question 15.
In which organelle of plant cell does the barcode genes are located? Name the genes.
Answer:
Chloroplast, the genes are matK and rbcL.

Question 16.
Differentiate between Monophyletic group and paraphyletic group.
Answer:
1. Monophyletic Group: Taxa comprising all the descendants of a common ancestor

2. Paraphyletic Group: Taxon that includes an ancestor but not all of the descendants of that ancestor.

Question 17.
Why do we need Cladistics?
Answer:
Cladistics:

1. Cladistics is now the most commonly used and accepted method for creating phylogenetic system of classifications.
2. Cladistics produces a hypothesis about the relationship of organism to predict the morphological characteristics of organism.
3. Cladistics helps to elucidate mechanism of evolution.

Question 18.
Write a note on the petals of papilionaceous Corolla.
Answer:
The outer most petal is large called standard petal or vexillum. Lateral 2 petals are lanceolate and curved. They are called wing petals or alae. Anterior two petals are partly fused and are called keel petals or carina which encloses the stamens and pistil.

Question 19.
Draw the floral diagram of Pisum sativum.
Answer:

Question 20.
Write systematic position of Solanaceae based on APG classification.
Answer:

Kingdom	Plantae
1. Clade	1. Angiosperms
2. Clade	2. Eudicot
3. Clade	3. Asterids
4. Clade	4. Solanales
5. Family	5. Solanaceae

Question 21.
Mention the diagnostic features of Liliaceae member.
Answer:
The diagnostic features of Liliaceae member:

1. Perennial herbs often with bulbous stem / rhizomes
2. Radical leaves
3. Perianth showy
4. Stamens six
5. Ovary superior

Question 22.
Write systematic position of liliaceae based of Bentham and Hooker Classification?
Answer:
Systematic Position:

Kingdom	Plantae
1. Class	1. Monocotyledons
2. Series	2. Coronarieae
3. Order	3. Liliales
4. Family	4. Liliaceae

IV. Long Answer Type Questions (5 Marks)

Question 1.
List out the principles of ICN.
Answer:
International Code of Nomenclature is based on the following six principles.

1. Botanical nomenclature is independent of zoological and bacteriological nomenclature.
2. Application of names of taxonomic group is determined by means of nomenclatural types.
3. Nomenclature of a taxonomic group is based on priority of publication.
4. Each taxonomic group with a particular circumscription, position and rank can bear only one correct name, the earliest that is in accordance with the rules except in specified cases.
5. Scientific names of taxonomic groups are treated as Latin regardless of their derivation.
6. The rules of nomenclature are retroactive unless expressly limited.

Question 2.
Explain the role of Botanical garden in taxonomy.
Answer:
Botanical gardens play the following important roles.

1. Gardens with aesthetic value which attract a large number of visitors. For example, the Great Banyan Tree (Ficus benghalensis) in the Indian Botanical Garden at Kolkata.
2. Gardens have a wide range of species and supply taxonomic material for botanical research.
3. Garden is used for self-instruction or demonstration purposes.
4. It can integrate information of diverse fields like Anatomy, Embryology, Phytochemistry, Cytology, Physiology and Ecology.
5. Act as a conservation centre for diversity, rare and endangered species.
6. It offers annual list of available species and a free exchange of seeds.
7. Botanical garden gives information about method of propagation, sale of plant material to the general public.

Question 3.
Enumerate the uses of Herbarium.
Answer:
The uses of Herbarium:

1. Herbarium provides resource material for systematic research and studies.
2. It is a place for orderly arrangement of voucher specimens.
3. Voucher specimen serves as a reference for comparing doubtful newly collected fresh specimens.
4. Voucher specimens play a role in studies like floristic diversity, environmental assessment, ecological mechanisms and survey of unexplored areas.
5. Herbarium provides opportunity for documenting biodiversity and studies related to the field of ecology and conservation biology.

Question 4.
Point out the characters of Early angiosperm according to APG Classification.
Answer:
The characters of Early angiosperm according to APG Classification:

1. Seeds always with two cotyledons.
2. Presence of ethereal oils.
3. Leaves are always simple net – veined
4. Each floral whorls with many parts
5. Perianth usually spirally arranged or parts in threes
6. Stamens with broad filaments
7. Anthers tetrasporangiate
8. Pollen monosulcate
9. Nectaries are rare
10. Carpels usually free and
11. Embryo very small

Question 5.
Draw a flow chart depicting the Bentham and Hooker Classification.
Answer:
Bentham and Hooker system of classification

Question 6.
Draw an outline of Engler & Prantl Classification.
Answer:

Question 7.
Define biosystematics & list out the aim of biosystematics.
Answer:
1. Biosystematics: Biosystematics is an “Experimental, ecological and cytotaxonomy” through which life forms are studied and their relationships are defined.
2. Aims of Biosystematics: The aims of biosystematics are as follows:

• To delimit the naturally occurring biotic community of plant species.
• To establish the evolution of a group of taxa by understanding the evolutionary and phylogenetic trends.
• To involve any type of data gathering based on modem concepts and not only on morphology and anatomy.
• To recognize the various groups as separate biosystematics categories such as ecotypes, ecospecies, cenospecies and comparium.

Question 8.
Distinguish between classical taxonomy & modern taxonomy.
Answer:
Classical Taxonomy:

1. It is called old systematics or Alpha (α) – taxonomy or Taxonomy
2. It is pre – Darwinean
3. Species is considered as basic unit and is static
4. Classification is mainly based on morphological characters
5. This system is based on the observation of a few samples / individuals

Modern Taxonomy:

1. It is called Neosystematics or Biosystematics or Omega (Ω) taxonomy
2. It is post – Darwinean
3. Species is considered as dynamic entity and ever changing
4. Classification is based on morphological, reproductive characters and phylogenetic (evolutionary) relationship of the organism
5. This system is based on the observation of large number of samples / individuals

Question 9.
List out the significance of Molecular Taxonomy.
Answer:
The significance of Molecular Taxonomy:

1. It helps to identify a very large number of species of plants and animals by the use of conserved molecular sequences.
2. Using DNA data evolutionary patterns of biodiversity are now investigated.
3. DNA taxonomy plays a vital role in phytogeography, which ultimately helps in genome mapping and biodiversity conservation.
4. DNA – based molecular markers used for designing DNA based molecular probes, have also been developed under the branch of molecular systematics.

Question 10.
Explain Clitoria ternatea in botanical terms. Draw floral diagram.
Answer:

1. Habit: Twining climber
2. Root: Branched tap root system having nodules.
3. Stem: Aerial, weak stem and a twiner.
4. Leaf: Imparipinnately compound, alternate, stipulate showing reticulate venation. Leaflets are stipellate.
   Petiolate and stipels are pulvinated.
5. Inflorescence: Solitary and axillary
6. Flower: Bracteate, bracteolate, bracteoles usually large, pedicellate, heterochlamydeous, complete, bisexual, pentamerous, zygomorphic and hypogynous.
7. Calyx: Sepals 5, synsepalous, green showing valvate aestivation. Odd repel is anterior in position.
8. Corolla: Petals 5, white or blue apopetalous, irregular papilionaceous corolla showing, descendingly imbricate aestivation.
9. Androecium: Stamens 10, diadelphous (9) + 1 nine stamens fused to form a bundle and the tenth stamen is free. Anthers are dithecous, basifixed, introse and dechising by longitudinal slits.
10. Gynoecium: Monocarpellary, uni – locular, with many ovules on marginal placentation, ovary superior, style simple and incurved with feathery stigma.
11. Fruit: Legume
12. Seed: Non – endospermous, reniform.
13. Floral Formula:
    

Question 11.
Explain Datura metal in botanical terms. Draw floral diagram.
Answer:

1. Habit: Large, erect and stout herb.
2. Root: Branched tap root system.
3. Stem: Stem is hollow, green and herbaceous with strong odour.
4. Leaf: Simple, alternate, petiolate, entire or deeply lobed, glabrous exstipulate showing unicostate reticulate venation.
5. Inflorescence: Solitary and axillary cyme.
6. Flower: Flowers are large, greenish white, bracteate, ebracteolate, pedicellate, complete, heterochlamydeous, pentamerous, regular, actinomorphic, bisexual and hypogynous.
7. Calyx: Sepals 5, green synsepalous showing valvate aestivation. Calyx is mostly persistant, odd sepal is posterior in position.
8. Corolla: Petals 5, greenish white, sympetalous, plicate (folded like a fan) showing twisted aestivation, funnel shaped with wide mouth and 10 lobed.
9. Androecium: Stamens 5, free from one another, epipetalous, altemipetalous and are inserted in the middle of the corolla tube. Anthers are basifixed, dithecous, with long filament, introse and longitudinally dehiscent.
10. Gynoecium: Ovary bicarpellary, syncarpous superior ovary, basically bilocular but tetralocular due to the formation of false septum. Carpels are obliquely placed and ovules on swollen axile placentation. Style simple long and filiform, stigma two lobed.
11. Fruit: Spinescent capsule opening by four special valves with persistent calyx.
12. Seed: Endospermous
13. Floral Formula:
    

Question 12.
Explain Allium cepa in botanical terms. Draw floral diagram.
Answer:
Botanical description of Allium cepa:

1. Habit: Perennial herb with bulb.
2. Root: Fibrous adventitious root system
3. Stem: Underground bulb
4. Leaf: A cluster of radical leaves emerges from the underground bulb, cylindrical and fleshy having sheathy leaf bases with parallel venation.
5. Inflorescence: Scapigerous i.e. the inflorescence axis (peduncle) arising from the ground bearing a cluster of flowers at its apex. Pedicels are of equal length, arising from the apex of the peduncle which brings all flowers at the same level.
6. Flower: Small, white, bracteate, bracteolate, pedicellate, complete, trimerous, actinomorphic and hypogynous. Flowers are protandrous.
7. Perianth: Tepals 6, white, arranged in two whorls of three each, syntepalous showing valvate aestivation.
8. Androecium: Stamens 6, arranged in two whorls of three each, epitepalous, apostamenous / free and opposite to tepals. Anthers dithecous. basifixed, introse and dehiscing longitudinally.
9. Gynoecium: Tricarpellary and syncarpous. Ovary superior, trilocular with two ovules in each locule on axile placentation. Style simple, slender with simple stigma.
10. Fruit: A loculicidal capsule.
11. Seed: Endospermous
12. Floral Formula:
    
    

Question 13.
List out the economic importance of plants & their uses of Fabaceae.
Answer:

Question 14.
List out the economic importance of plants & their uses of Solanaceae.
Answer:

Question 15.
List out the economic importance of plants & their uses of Liliaceae.
Answer:
Economic Importance of the Family Liliaceae:

V. Higher Order Thinking Skills (HOTs)

Question 1.
Neem is highly valued tree in Indian medicine. It is called by the name veppu in Malayalam, Arishta in Sanskrit, Vembu in Tamil, Nimbo in Portuguese. Suggest a solution for this varied naming problem considering as a taxonomist.
Answer:
As a taxonomist, this can be solved by using Binomial nomenclature. According to ICBN, every plant is given a scientific name which can be used in common all throughout the world. Thus neem is named as Azadirachta indica.

Question 2.
According to Binomial nomenclature, Human beings are named as Homosapiens. Following this, write the binomials for Brinjal and Rosewood.
Answer:
The binomials for Brinjal and Rosewood:

1. Brinjal – Solatium melongena
2. Rosewood – Dalbergia latifolia

Question 3.
Officially, every state in the Republic of India has its own flower, fruit etc. If Andhra Pradesh has Lotus as its state flower, what is the state flower of Tamil Nadu? Mention its family.
Answer:
State flower of Tamilnadu is Gloriosa superba belonging to Liliaceae family.

Question 4.
Peanut is a geocarpic fruit – Comment on the statement.
Answer:
In peanut (Arachis hypogea), after fertilisation, the stipe of ovary grows down into the soil, later develops & matures into fruit. Such a underground developed fruit is called geocarpic fruit.

Question 5.
You are given an entire plantlet of Clitoria ternatea. Give possible reasons to say that it is a dicot plantlet.
Answer:
Clitoria ternatea belongs to Dicots because:

1. The root is a tap root
2. Leaves show reticulate venation

Question 6.
Give possible terms explaining the gynoecium of a flower whose C.S. of ovary is given below.
Answer:

Tricarpellary, Trilocular, Syncarpous, 2 ovules in 1. Each ovule has axile placentation.

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