Category: Class 7

Students can Download Science Chapter 6 Health and Hygiene Questions and Answers, Notes Pdf, Samacheer Kalvi 7th Science Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 7th Science Solutions Term 1 Chapter 6 Health and Hygiene

Samacheer Kalvi 7th Science Health and Hygiene Textual Evaluation

I. Choose the appropriate answer :

Health And Hygiene 7th Standard Question 1.
Ravi has sound mind and physically fit body. Which refers to
(a) Hygiene
(b) Health
(c) Cleanliness
(d) Wealth
Answer:
(b) Health

Health And Hygiene Class 7 Question 2.
Sleep is not only good for body, but it is also good for
(a) Enjoyment
(b) Relaxation
(c) Mind
(d) Environment
Answer:
(c) Mind

7th Science Health And Hygiene Question 3.
Our living place should be
(a) Open
(b) Closed
(c) Clean
(d) Unclean / Untidy
Answer:
(c) Clean

7th Standard Science Health And Hygiene Question 4.
The tobacco chewing causes
(a) Anamia
(b) Periodontitis
(c) Tuberculosis
(d) Pneumonia
Answer:
(b) Periodontitis

Samacheer Kalvi Guru 7th Science Question 5.
The first aid is to
(a) To save money
(b) To prevent scars
(c) To prevent the medical care
(d) To relieve the pain
Answer:
(d) To relieve the pain

II. Fill in the blanks :

Health And Hygiene Questions And Answers Pdf Question 1.
A group of people living together in a particular area is called ______
Answer:
Community

Samacheer Kalvi Guru Science 7th Question 2.
Iam green colour box with garbage. Who am I ?
Answer:
Bio degradable waste

Health And Hygiene Class 7 Questions And Answers Question 3.
Eyes are considered as to the world.
Answer:
windows

Samacheer Kalvi Guru 7th Standard Science Question 4.
The hair follicles produce which keeps the hair smooth.
Answer:
oil

Health And Hygiene Chapter Question 5.
Tuberculosis is caused by the bacterium .
Answer:
Mycobacterium tuberculae

III. True (or) False, If false give the correct statement.

Health And Hygiene Questions And Answers Question 1.
All food should be covered.
Answer:
True

Samacheer Kalvi Guru 7th Science Guide Question 2.
Chicken pox also known as Leucoderma.
Answer:
(False) Correct statement: Chicken pox is also known as vanicella.

Question 3.
Stomach ulcer is a non-commnicable disease.
Answer:
True.

Question 4.
Rabies is a fatal disease.
Answer:
True

Question 5.
First- degree bums damage the whole skin.
Answer:
False. Correct statement: First -degree bums affects the outer layer (epidermis) of the skin only

IV. Match the following:

1.	Rabie	(a)	Salmonella
2.	Cholera	(b)	Yellow urine
3.	Tuberculosis	(c)	Cramps in legs
4.	Hepatitis	(d)	Hydrophobia
5.	Typhoid	(e)	Mycobacterium

Answer:

1. d
2. c
3. e
4. b
5. a

V. Analogy.

Question 1.
First degree bum: epidermis :: second degree bum : _________
Answer:
Dermis.

Question 2.
Typhoid: Bacteria:: Hepatitis: _________
Answer:
Vims.

Question 3.
Tuberculosis : air:: Cholera: _________
Answer:
Water.

VI. Choose the correct alternative from the following:

Question 1.
Assertion (A) : Oral hygiene is good.
Reason (R) : Sound teeth and healthy gums with healthy surrounding tissues,
(a) Both A and R are true
(b) Both A and R are false
(c) A is true but R is false
(d) A is false but R is true
Answer:
(a) Both A and R are true

Question 2.
Assertion (A): Chicken pox is a viral communicable disease.
Reason (R) : Characterized by rashes on the whole body, fever, head ache and tiredness.
(a) Both A and R are true
(b) Both A and R are false
(c) A is true but R is false
(d) A is false but R is true
Answer:
(a) Both A and R are true

VII. Very short Answer.

Question 1.
What is hygiene?
Answer:
Hygiene refers to the good habits and their practices which is followed to prevent disease, maintain good health, especially through cleanliness, consumption of safe drinking water and proper disposal of sewage. It refers to all those activities that are done for improving and maintaining good health and sound mind.

Question 2.
Write about the right way of protect the eyes?
Answer:
Practices to be followed for eye care.

1. Do not rub the eyes
2. Do not watch TV / Computer for a long time.
3. Use cold water for cleaning the eyes.
4. Eat lot of carrots which is rich in vitamin A needed for good vision.
5. Eat fruits like oranges, sweet lemon etc., regularly.

Question 3.
How to keep your hair clean and health?
To keep the hair clean and healthy:
Answer:

1. The regular hair wash and massage of the scalp will remove the dead skin cells, excess oil and dust.
2. Rinsing the hair well with clear water and using good toothed comb for hair dressing is highly essential for their maintenance.

Question 4.
Sobi frequently playing with her mobile, suggest your ideas to protect his eye from irritation?
Answer:

1. Stop playing with the mobile for a long time
2. Keep the mobile at a distance from the eyes while playing.
3. Wash eyes with cold water at intervals.

Question 5.
Give any two communicable disease, which spreads in your locality during monsoon?
Answer:

1. Cholera
2. Diarrhoea

Question 6.
What first aid will you provide in the case of bruises?
Answer:

1. Bruises refer to scratches. It is a surface damage that does not penetrate the lower tissues.
2. The affected area should be washed with cold running water and cleaned with an antiseptic cram on the wound.

Question 7.
Ravi said “Ganga had minor burn, so I washed with water” Do you agree with his statement or not? Explain Why?
Answer:

1. Yes, In case of minor bums, the affected area should be washed with cold water.
2. In case of severe bums, deeper layers of tissues get destroyed and blisters appear.

VIII. Short answer.

Question 1.
Why the first aid is essential?
Answer:
Safety and First Aid
First aid is the immediate treatment given to the victim of trauma or sudden illness before medical help is made available. The first aid is

1. To save the life
2. To prevent further bleeding and determine the condition of the patient.
3. To relive the pain
4. To provide a medical care available at the earliest

Question 2.
What is this picture? Explain.

Answer:
It says that “Waste should not be thrown there”.

Question 3.
Distinguish between the following pairs Communicable diseases and Non communicable diseases.
Answer:

S.no
1.	These diseases spread from one person to another person.	These diseases do not spread from one person to another person.
2.	They are spread through contaminated air, water, food or vectors, e.g Tuberculosis, Cholera.	They are caused due to wearing out of body parts or malnutrition etc., eg. Goiter, Night blindness.

Question 4.
What steps you will follow to keep the teeth healthy?
Answer:

1. Good oral hygiene implies sound teeth and healthy gums with healthy surrounding tissues.
2. When you brush two times a day, it will prevent the formation of tartar and plaque on, your teeth and gums.
3. When you floss, it will remove food particles, plaque, and bacteria which build up between your teeth. When you start flossing, your gums may bleed a little bit, but after few days that will be stopped.
4. It should be started only with proper medical guidance.
5. Eat a well balanced diet and avoid habits like chewing tobacco.

Question 5.
Name the mode of transmission of communicable disease.
Answer:
Communicable diseases spread from one person to another person through various modes as given below.
Mode of Transmission:

1. Food and water borne diseases – e.g Cholera, Typhoid
2. Air borne diseases – e.g Tuberculosis, cold
3. Insect other animals borne diseases – e.g Malaria, Rabies.
4. Contaminated food and water, air and Insects are the modes for transmission of communicable disease.

Question 6.
The hair is thin, spares and lost very often. Suggested your ideas to reduce this problem?
Answer:
The condition of the hair reflects the nutritional status and general health of the body. Thin, sparse and lots of hair indicates poor nutritional status.
The following measures will help to maintain hair growth and avoid hair loss.

1. The regular hair wash and massage of the scalp will remove the dead skin cells, excess oil and dust.
2. Rinsing the hair well with clear water and using good toothed comb for hair dressing is highly essential for their maintenance.
3. Eating a balanced diet which provides all nutrients needed for the body will promote hair growth.
4. Applying oil to the skin and massaging the scalp will promote hair growth.
5. Use of chemicals (dyes, shampoos) must be used to avoid hair loss.

IX. Answer in Details.

Question 1.
Write about any three communicable diseases in details.
Answer:
Communicable diseases are those that spread from one person to another. Diseases spread through contaminated air, water, food or vectors (insects and ohter animals) are palled as communicable diseases.

Tuberculosis:

1. Tuberculosis is caused by Mycobacterium tuberculae.
2. It spreads from one person to another person through air by spitting and prolonged contact with sharing materials of the patient.

Symptoms:
Fever, weight loss, Chronic cough, blood spitting and difficulty in breathing.

Prevention and treatment:

1. Getting BCG vaccination
2. Giving special attention to the patient,
3. Regular medication like DOT

Cholera:

1. Cholera is caused by Vibrio cholera.
2. It spreads through the consumption contaminated food or water.

Symptoms:
The symptoms of Cholera is vomiting, severe diarrhoea and cramps in legs.

Hepatitis:

1. Hepatitis is one of the most dangerous and fatal diseases caused by Hepatitis Virus A, B, C, D, E.
2. Its mode of transmission are contaminated water, sharing of needles and blood transfusion.

Symptoms:
Loss of appetite, (Anorexia), vomiting, eyes and urine in yellow color.

Prevention and treatment:

1. Drink boiled water.
2. Proper cleaning of hands.

Question 2.
List the situations in which first aid is given. What would you do if a person suffers from skin burns?
Answer:
The tissue damage caused by heat, chemical, electricity, sunlight or nuclear radiation is known as Bums. Mostly bums are caused by scalds, building fires, flammable liquid and gases. According to burning. There are three types of bums.

1. First-degree bums affect only the outer layer (called the epidermis) of the skin.
2. Second-degree bums damage the epidermis and the layer beneath it called ther dermis.
3. Third -degree bums involve damage or complete destruction of the skin to its full depth and damage to underlying tissues also. People who experience such bums often require skin grafting.

First Aid for Burning
In case of minor bums, the affected area should be washed with cold water and an antiseptic cream should be applied. In case of severe bums, where deeper layers of tissues get destroyed and blisters appear, use of water should be avoided. The burnt area should be covered with a clean non-sticking cloth or bandages. Larger bums need immediate medical attention.
It is very important to keep a fire extinguisher readily available.

Question 3.
How the disease are transmitted from one person to the other person?
Answer:
Communicable Diseases are those that spread from one person to another. Diseases spread through contaminated air, water, food or vectors (insects and ohter animals) are called as Communicable diseases.

1. The communicable diseases are caused by disease causing microbes such as Bacteria, viruses etc.
2. These microbes are found in contaminated food, water, air etc.
3. Some of them like the malarial parasite complete their life cycle in the body of a mosquito.
4. Thus air food and water, sweat act as modes of transmitting these microbes from an infected person to a healthy person.
5. E.g. The cycle given below shows how food and water borne diseases are transmitted.
   

S.no	Mode of Transmission	Examples
1	Contaminated food and water	Cholera, Typhoid
2	Contaminated air	Tuberculosis
3	Insect / Animal borne diseases	Malaria, Rabies

X. Higher Order thinking question

Question 1.
A person is sleeping during day time. Why does this happen with some people that they feel sleepy during day time in office or in the classroom. Have you ever come across such situation? Explain.

Answer:

1. Many people are tired and do not have the energy to perform day to day activities. They tired and tend to sleep in the classroom or work place. Though sleep can be due to various reasons, the common reason for this condition is Anaemia.
2. People who are Anaemic have less number of Red blood cells in their blood.
3. The Red blood cells have haemoglobin which caries oxygen to all the cells of the body.
4. People who are Anaemic will have less slow oxygen supply to all the cells of the body.
5. Energy production in the cells is less and they feel tired and sleepy always. This is due to in the diet. Prevention : Eat food rich in Iron.

Samacheer Kalvi 7th Science Health and Hygiene Additional Questions

I. Choose the appropriate answer.

Question 1.
Anorexia means _______
(a) Excess thirst
(b) Excess sweating
(c) Loss of hair
(d) Loss of appetite
Answer:
(d) Loss of appetite

Question 2.
Drinking boiled water can prevent _______
(a) Tuberculosis
(b) Rabies
(c) Cholera
(d) Chicken pox
Answer:
(c) Cholera

Question 3.
High fever is a symptom of _______
(a) Rabies
(b) Typhoid
(c) Scurvy
(d) Hepatits
Answer:
(b) Typhoid

Question 4.
_______ is a non communicable disease.
(a) small pox
(b) Varicella
(c) Rheumatism
(d) Flu
Answer:
(c) Rheumatism

Question 5.
Intake of _____ can help to prevent Anaemia.
(a) cod liver oil tablet
(b) oranges
(c) whole egg
(d) eggs
Answer:
(a) cod liver oil tablet

II. Fill in the Blanks.

1. Dengue causes decrease in number of _______ in blood
2. _____ is a non communicable disease caused by loss of pigmentation in the skin.
3. The pigment present in our skin is _______
4. Extreme fear for water is called _______
5.  _______ vaccine prevents Tuberculosis.

Answer:

1. Platelets
2. Leucoderma
3. Melanin
4. hydrophobia
5. BCG

III. True or False – if false give the correct statement.

Question 1.
Rabies can be caused by the bite of monkeys.
True.

Question 2.
We must eat lot of carrots to prevent eye diseases.
Answer:
True.

Question 3.
Chronic cough is a symptom of Typhoid.
Answer:
(False) Correct Statement: Chronic cough is a symptom of Tuberculosis.

Question 4.
Raju drank water in a fair and was affected by Dengue. Is this statement True or False.
Answer:
(False) Correct Statement: Dengue is not a water borne disease.

Question 5.
Bum injuries can be fatal.
Answer:
True

Question 6.
Alcoholism is a communicable disease.
Answer:
(False) Correct Statement: Alcoholism is a Non-communicable disease.

IV. Match the following :

Question 1.

Pellagra	(a)	Water
Allergies	(b)	Folic acid
Rabies	(c)	Pollen
Anaemia	(d)	skin

Answer:

1. d
2. c
3. a
4. b

Question 2.

Hepatitis	(a)	Citrus fruits
Nightblindness	(b)	Vomiting
Bleeding gums	(c)	smoking
Heart attack	(d)	Poor light

Answer:

1. b
2. d
3. a
4. c

V. Analogy.

Question 1.
Leucoderma: Melanin
Anaemia: ______.
Answer:
Iron.

Question 2.
Tuberculosis : Lungs
Rabies : _____.
Answer:
Nervous system.

VI. Assertion and Reason.

(a) Both A and R are true
(b) Both A and R are false
(c) A is true but R is false
(d) A is false but R is true

Question 1.
Assertion (A) : We must offer first aid to a bleeding person.
Reason (R) : We must not use gloves while helping them.
(a) Both A and R are true
(b) Both A and R are false
(c) A is true but R is false
(d) A is false but R is true
Answer:
(c) A is true but R is false

Question 2.
Assertion (A) : Antibiotics do not help to cure communicable diseases.
Reason (R) : They are caused by microbes.
(a) Both A and R are true
(c) A is due but R is false
(d) A is false but R is true
(b) Both A and R are false
Answer:
(d) A is false but R is true

VII. Complete the table.

Question 1.
Tuberculosis _______
________ Virus
Answer:
Bacteria,Hepatitis

Question 2.
Night Blindness ________
_________ Iron
Answer:
Vitamin A, Anaemia

Question 3.
BCG __________
________ Chicken pox
Answer:
Tubeculosis, Varicella Vaccine

Question 4.
Dog ________
________ Dengue
Answer:
Rabies,Mosquito

Question 5.
Tuberculosis ________
__________ Rashes
Answer:
Chronic cough, Chicken pox

VIII. Very short Answers:

Question 1.
Name some diseases which affect the teeth.
Answer:
Bleeding gums, Tooth decay, periodontis.

Question 2.
List two measures to maintain community hygiene.
Answer:

1. The surroundings should be kept clean.
2. Drains should be covered properly.

Question 3.
Name two disease which can be prevented by vaccination.
Answer:
Polio, Tuberculosis.

Question 4.
Name some diseases caused by lack of trace elements in the body.
Answer:
Anemia, pellagra, night blindness and xerophthalmia, goiter and hypothyroidism.

Question 5.
What is a Vaccine?
Answer:

1. A vaccine is a biological preparation that provides active acquired immunity to a particular disease.
2. Vaccine (BCG, Polio, MMR) are given at early childhood to protect from other diseases.

Question 6.
How can we prevent fatality in the case of Rabies?
Answer:
Timely vaccination before the onset of symptoms can prevent fatality in the case of Rabies.

IX. Short Answer.

Question 1.
Write a note on non-communicable diseases.
Answer:

1. Communicable diseases do not spread from person to person. They are caused by other factors.
2. Antibiotics, or medicines that fight against germs, do not help to cure non- communicable diseases.
3. Problems caused by wearing out of body parts:
   Rheumatism, heart attack, epileptic seizures, stroke, migraine headaches, Cataract and cancer.
4. Problems caused by external harmful agents entering the body:
   Allergies, asthma, poisons, snakebite, cough from smoking, stomach ulcer, alcoholism.
5. Problems caused by a lack of trace elements in the body:
   Anaemia, pellagra, night blindness and xerophthalmia, goiter and hypothyroidism.

Question 2.
Write a note on Chicken pox.
Answer:

1. Causal agent :Chickenpox (chicken pox), also known as varicella, is a highly contagious infection caused by the varicella zoster virus.
2. This disease spreads through air and contact with an infected person.
3. Symptoms: A appearance of rashes on the whole body, fever, headache and tiredness.
4. Prevention and treatment: The chickenpox (Varicella) vaccine is the best way to prevent chickenpox. Special attention should be given to the infected persons.

Question 3.
Write a note an Rabies.
Answer:

1. Rabies is a fatal disease, which is transmitted by the bite of the infected dog, rabbit, monkey, cat etc.
2. Causal agent: The virus present in the saliva of dog enters the brain via neurons.
3. Symptoms: The symptoms of rabies is hydrophobia (extreme fear for water), fever for 2-12 weeks and exaggerations in behavior.

Prevention and treatment

1. In early stages rabies is very difficult to detect.
2. After an animal is bitten it usually takes two to twelve weeks to shows any symptoms and it may take as long as two years also.
3. Fatality can be prevented by timely vaccination before the onset of symptoms.

Question 4.
We should use a handkarchief when we sneeze, Justify.
Answer:
When we are suffering from cold etc, the virus comes out with the droplets and spreads in air. This can infect a healthy individual. Thus we should use a handkerchief while sneezing.

Question 5.
What can we do to maintain personal hygiene?
Answer:

1. We must brush our teeth at least twice a day.
2. We must have a shower daily.
3. We must wash our hair regularly.
4. We must wash our face and hands regularly.
5. We should keep food covered with a lid.
6. We should wear washed and clean clothes.
7. We must wear slippers while we go out of the house. Drinking water must be stored in a clean and safe place.

X. Long Answer

Question 1.
List the diseases affecting the eye, their causative agents, impact and Remedial measures.
Answer:

S. No	Name of the Disease	Causative Agents	Impacts / Consequences	Remedial measures.
1.	Night Blindness	Lack of vitamin A, a disorder of the cells in your retina	Makes it hard to see well at night or in poor light.	Eat foods rich in antioxidant, vitamins and minerals.
2.	Conjuncitvitis (Pink eye)	Caused by a virus and bacteria	One or both eyes can be affected. Highly contagious; can be spread by coughing and sneezing	Antibiotic eye drops or ointments, home remedy
3.	Color blindness	genetic condition	1.  Difficulty distinguishing between colors. 2.   Inability to see shades or tones of the same color	There is no known cure for color blindness. Contact lenses and glasses are available with filters to help color deficiencies

XI. Hots

Question 1.
Richa had a pet dog. She vaccinated him regularly. He suddenly bit a stranger. Do you think that the person could have got Rabies.
Answer:
No, since the dog was vaccinated regularly, there is no chance of the person suffering from Rabies. But still the person should seek medical advise for the treatment.

Students can Download Social Science Geography Chapter 1 Interior Of The Earth Questions and Answers, Notes Pdf, Samacheer Kalvi 7th Social Science Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 7th Social Science Geography Solutions Term 1 Chapter 1 Interior Of The Earth

Samacheer Kalvi 7th Social Science Interior Of The Earth Textual Evaluation

I. Choose the correct answer:

Samacheer Kalvi Guru 7th Social Science Question 1.
Nife is made up of _______
(a) Nickel and ferrous
(b) Silica and aluminum
(c) Silica and magnesium
(d) Iron and magnesium
Answer:
(a) Nickel and ferrous

Samacheer Kalvi 7th Social Science Books Answers Question 2.
Earthquake and volcanic eruption occur near the edges of _______
(a) Mountain
(b) Plains
(c) Plates
(d) Plateaus
Answer:
(a) Mountain

Samacheer Kalvi 7th Social Science Book Back Answers Question 3.
The magnitude of an earthquake is measured by _______
(a) Seismograph
(b) Richter scale
(c) Ammeter
(d) Rotameter
Answer:
(b) Richter scale

Social Samacheer Kalvi 7th Question 4.
The narrow pipe through which magma flow out is called a _______
(a) Vent
(b) Crater
(c) Focus
(d) Caldera
Answer:
(a) Vent

Samacheer Kalvi Guru 7th Social Science Guide Question 5.
Lava cones are _______
(a) mountains of accumulation
(b) mountains of deformation
(c) relicit mountains
(d) fold mountains
Answer:
(a) mountains of accumulation

Samacheer Kalvi 7th Standard Social Question 6.
The top of the cone of a volcanic mountain has a depression known as the _______
(a) crater
(b) lopith
(c) caldera
(d) sill
Answer:
(a) crater

Interior Of The Earth Question Answer Question 7.
_______ belt is known as the “Ring of Fire”.
(a) Pacific
(b) Atlantic
(c) Arctic
(d) Antarctic
Answer:
(a) Pacific

II. Fill in the Blanks

7th Standard Samacheer Kalvi Social Question 1.
The core is separated from the mantle by a boundary called _______
Answer:
Weichart – Gutenberg discontinuity

Interior Of The Earth Book Back Answers Question 2.
The earthquake waves are recorded by an instrument known as _______
Answer:
seismograph

7th Standard Geography Guide Question 3.
Magma rises to the surface and spreads over a vast area is known as _______
Answer:
fissure eruption

Samacheer Kalvi Guru 7th Social Question 4.
An example for active volcano _______
Answer:
St. Helens USA

Samacheer Kalvi 7th Social Question 5.
Seismology is the study of _______
Answer:
earthquake

III. Circle the odd one

Samacheer Kalvi 7th Social Guide Question 1.
crust, magma, core, mantle
Answer:
magma

Samacheer Kalvi 7th Social Answers Question 2.
focus, epicenter, vent, seismic waves
Answer:
vent

Samacheer Kalvi 7th Social Science Guide Question 3.
Uttar Kashi, Chamoli, Koyna, Krakatoa
Answer:
Krakatoa

Samacheer Kalvi 7th Social Book Answers Question 4.
lava, caldera, silica, crater
Answer:
silica

Samacheer Kalvi 7th Social Science Question 5.
Stromboli, Helens, Hawaii, Fujiyama
Answer:
Fujiyama

IV. Match the following

Earth quake	(i)	Japanese term
Sima	(ii)	Africa
Pacific Ring of Fire	(iii)	Sudden movement
Tsunami	(iv)	Silica and magnesium
Mt. Kenya	(v)	World volcanoes

Answer:

1. iii
2. iv
3. v
4. i
5. ii

V. Consider the following statement and (✓) Tick the appropriate answer.

Samacheer Kalvi.Guru 7th Social Question 1.
Assertion (A): There structure of the earth may be compared to that of an Apple.
Reason (R) : The interior of the earth consists of crust, mantle and core.
(a) A and R are correct and A explains R
(b) A and R are correct but A does not explain R
(c) A is incorrect but R is correct
(d) Both A and R are incorrect
Answer:
(a) A and R are correct and A explatns R

Question 2.
Assertion (A): The Pacific Ocean includes two thirds of the world’s volcanoes.
Reason (R) : The boundary along the Eastern and Western coast areas of the Pacific
Ocean is known as the Pacific Ring of Fire.
(a) A and R are correct and A explains R
(b) A and R are correct but A does not explain R
(c) A is incorrect but R is correct
(d) Both A and R are incorrect
Answer:
(a) A and R are correct and A explains

VI. Answer in a word

Question 1.
Name the outer most layer of the earth.
Answer:
Crust

Question 2.
What is SIAL?
Answer:
Silica and Alumina.

Question 3.
Name the movement of the Earth’s lithospheric plates.
Answer:
Tectonic movements

Question 4.
Give an example of extinct volcano.
Answer:
Mt. Popa of Myanmar

VII. Answer the following briefly:

Question 1.
What is mantle?
Answer:
The layer of the earth beneath the crust is called the mantle. It is separated from the crust by a boundary called Mohorovicic discontinuity.

Question 2.
Write note on the core of the earth.
Answer:
The innermost layer of the earth is called the core. It is also known as barysphere. It is separated from the mantle by a boundary called Weichart-Gutenberg discontinuity. The core is also divided into two parts.

1. The outer core, which is rich in iron, is in liquid state.
2. The inner core, composed of Nickel and Ferrous (Nife), is solid in state.

Question 3.
Define Earthquake.
Answer:
A sudden movement of a portion of the earth’s crust which produces a shaking or trembling is known as an earthquake.

Question 4.
What is a Seismograph?
Answer:
The earthquake waves are recorded by an instrument known as seismograph.

Question 5.
What is a volcano?
Answer:
A volcano is a vent or an opening in the earth’s crust through which hot magma erupts from deep below the surface. The opening is usually circular in form.

Question 6.
Name the three types of volcanoes based on shape.
Answer:
On the basis of shape, there are three types of volcanoes. They are:

1. Shield volcano
2. Cinder-cone volcano
3. Composite volcano

VIII. Give reason

Question 1.
No one has been able to take samples from the interior of the earth
Answer:
The innermost layer of the earth is called the core. The central core has very high temperature and pressure. So no one has been able to take samples from the interior of the earth.

Question 2.
The Continent crust is less dense than the oceanic crust
Answer:
Despite greater thickness, the continental crust is less dense than the oceanic crust because it is made of both light and dense rock typps.

IX. Distinguish between

Question 1.
SIAL and SIMA
Answer:

S.No	SIAL	SIMA
1.	The upper part of the earth’s crust.	The lower part of the crust.
2.	Has granite rocks and forms continents.	Continuous zone of denser basaltic rocks forming ocean floor.
3.	Has silica and Alumina referred to as SIAL	Has silica and Magnesium called SIMA

Question 2.
Shield volcano and composite volcano
Answer:

S.No	Shield volcano	Composite volcano
1.	A shield volcano is formed by quiet eruption of lava with a low silica content.	Composite volcanoes are made of alternate layers of lava, cinder and ash.
2.	Eg. Volcanoes of the Hawaii islands	Eg. St. Helens in USA

Question 3.
Active volcano and dormant volcano
Answer:

S.No	Active volcano	Dormant volcano
1.	Active Volcanoes erupt frequently.	Dormant Volcanoes have shown no sign of activity for many years but may become active at any time.
2.	Eg. St.Helens in USA, Pinatubo in Philippines.	Eg. Mt Fujiyama in Japan, Mt. Krakatoa of Indonesia

X. Answer the following questions in detail

Question 1.
Write about the effects of an earthquake.
Answer:

1. Earthquakes may cause changes in the earth’s surface. Vibrations often set landslides in mountainous regions.
2. A greater danger in an earthquake is the falling of buildings.
3. Fire is another great danger. Underground water system is naturally disturbed by such movements.
4. An earthquake which originates below or near the sea causes great disturbance in the water.
5. Tsunami, a Japanese term, is the name given to the huge wave caused in the sea by an earthquake.

Question 2.
Describe the classification of volcanoes based on the eruptions.
Answer:

1. Volcanoes are also grouped according to their periodicity of eruptions such as active, dormant and extinct.
2. These names refer to the state of activity rather than the types of volcanoes
3. Active Valcanoes that erupt frequently are called active volcanoes. Most of the active volcanoes lie in the Pacific Ring of Fire belt which lies along the Pacific coast.
4. Mt. Stromboli in Mediterranean Sea, St.Helens in USA, Pinatubo in Philippines.
5. Dormant volcanoes have shown no sign of activity for many years but they may become active at any time. It is also called Sleeping Volcano
6. Vesuvius mountain of Italy, Mt Fujiyama in Japan, Mt. Krakatoa of Indonesia are famous examples of this types.
7. Extinct The top of extinct volcanic mountains have been eroded. Mt Popa of Myanmar and Mt. Kilimanjaro and Mt. Kenya of Africa are examples of extinct volcanoes.

Question 3.
Name the major zones of volcanic activity and explain any one.
Answer:
There are three major zones of volcanic activities in the world. They are:

1. The Circum – Pacific belt
2. The Mid continental belt
3. The Mid Atlantic belt

Circum Beit
This is the volcanic zone of the convergent oceanic plate boundary. It includes the volcanoes of the eastern and western coastal areas of Pacific Ocean. This zone is popularly termed as the Pacific Ring of Fire which has been estimated to include two-thirds of the world’s volcanoes

XI. HOTs

Question 1.
The earth’s interior is very hot. Why?
Answer:

1. The inner most layer of the earth, called the core has two parts, the outer core and the inner core.
2. The outer core is rich in iron and is in liquid state.
3. The inner core is made of Nickel and Ferrous which is in solid state.
4. The central core has very high temperature and pressure

Question 2.
Are Volcanoes Destructive (or) Constructive?
Answer:
Volcanoes are constructive and Destructive.
Constructive effects:

1. Volcanoes provide nutrients to the surrounding soil as volcanic ash contains minerals beneficial to plants.
2. Some plateaus and plains are formed due to volcanic eruption.
3. They cool off the earth removing heat from the interior.

Destructive effects:

1. They cause earth quakes, fast floods, mud slides and rock falls.
2. Dust and Ash that come out of volcanoes are very harmful to living things.

Question 3.
How does volcaone make on Island?
Answer:
Some volcanoes are found under oceans . If an underwater volcano keeps erupting, it can rise above the ocean’s surface and thus as Island is formed.

XII. Activity

Question 1.
On an outline map of the world, mark the Pacific Ring of Fire
Answer:

Question 2.
Lable the parts of volcano.
Answer:

Question 3.
Prepare an album on earthquake and volcanoes
Answer:
Activity to be done by the students themselves

Puzzle

Answer:

Across
1. Point of origin of Earthquake
4. Molten rock under the surface
5. Waves triggered by deep ocean earthquake
6. Inner layer of the Earth

Down
2. Extinct volcano in Europe
3. Top layer of the Earth
4. Middle layer of Earth

Samacheer Kalvi 7th Social Science Interior Of The Earth Additional Questions

I. Choose the correct answer:

Question 1.
An earth quake of magnitude ________ scale can cause damage from things falling.
(a) 3.0
(b) 4.0
(c) 5.0
(d) 2.0
Answer:
(c) 5.0

Question 2.
In India, the Himalayan region and the ________ valley are prone to earthquakes.
(a) Ganga – Brahmaputra
(b) Yamuna
(c) Sind
(d) Sutle
Answer:
(a) Ganga-Brahmaputra

Question 3.
If the crater of a volcano is of great size and is shaped like a basin, it is called a ________
(a) Vent
(b) Crater
(c) Caldera
(d) Magma
Answer:
(c) Caldera

Question 4.
Volcanoes made of cinder and ash and which have sleep slopes are ________ volcanoes.
(a) Shield
(b) Cinder-cone
(c) Composite
(d) Dormant
Answer:
(c) Composite

II. Fill in the Blanks

1. The scientific study of volcanoes is called ________
2. People who study volcanoes are called ________
3. Lava flow is affected by ________
4. Barren island is situated in the ________
5. ________ is known as the light house of Mediterranean sea.
6. Iceland, the most active volcanic area is located on the ________

Answer:

1. Volcanology
2. Volcanologists
3. Andaman sea
4. Stramboli
5. Mid-Atlantic ridge

III. Circle the odd one

1. Active volcano, Dormant volcano, Extinct volcano, Shield volcano
2. Mt. Popa, Mt. Fujiyama, Mt. Kilimanjaro, Mt. Kenya.
3. Vesuvius, Stromboli, St.Helena, Etna.

Answer:

1. Shield volcano
2. Mt. Fujiyama
3. St.Helena

IV. Match the following

Earth	i	Trembling
Core	ii	Andaman
Earthquake	iii	Light house
Barren island	iv	Barysphere
Stramboli	v	Blue planet

Answer:

1. v
2. iv
3. i
4. ii
5. iii

V. Consider the following statement and Tick the appropriate answer:

Question 1.
Statement 1: When magma rises slowly to the surface and spreads over a vast area. It is known as fissure eruption
Statement 2 : The viscosity of lava is determined by the amount of silica and water in magma.
(a) 1 is true, 2 is wrong.
(b) 1 is wrong, 2 is true.
(c) Both the Statements are true.
(d) Both the Statements are wrong.
Answer:
(c) Both the Statements are true.

Question 2.
Statement 1: Many volcanoes of Mexico and Central America are cinder-cone volcanoes.
Statement 2 : Shield volcano is also called strato volcano.
(a) 1 is true, 2 is wrong.
(b) 1 is wrong, 2 is true.
(c) Both the Statements are true.
(d) Both the Statements are wrong.
Answer:
(a) 1 is true, 2 is wrong
Hints: composite volcano is also called strato volcano.

VI. Answer in a word

Question 1.
What is the raduis of the earth?
Answer:
6371

Question 2.
Name the point where the vibrations originate in an earthquake.
Answer:
Focus.

Question 3.
What is the point of the earth’s surface directly above the focus called?
Answer:
Epicentre.

Question 4.
Tsunami when did Indian ocean attack coastal area of Indonesia, India Srilanka and Thailand.
Answer:
26th December 2004.

VII. Answer the following in Brief.

Question 1.
What are endogenic and exogenic forces?
Answer:
The forces which act in the interior of the earth are called as Endogenic forces and the forces that work on the surface of the earth are called as Exogenic forces.

Question 2.
What is explosive eruption?
Answer:
If the magma rises quickly to the surface, lava is thrown high into the atmosphere. Besides lava, ash, steam, gases and pieces of rocks are also thrown out. This type of eruption is known as explosive eruption.

Question 3.
Mention any 2 causes of earthquake.
Answer:

1. The chief cause of earthquake is the sudden slipping of the portion of the earth’s crust along fractures or faults.
2. Another cause of earthquake is volcanic activity.

Question 4.
What is asthenosphere?
Answer:
The asthenosphere is the part of the mantle that flows and moves the plates of the earth.

VIII. Answer the following questions in detail.

Question 1.
Explain three major zones of volcanic activities in the world.
Answer:
There are three major zones of volcanic activities in the world. They are:

1. The Circum – Pacific belt
2. The Mid continental belt
3. The Mid Atlantic belt

1. Circu m Belt: This is the volcanic zone of the convergent oceanic plate boundary. It includes the volcanoes of the eastern and western coastal areas of Pacific Ocean.

2. Mid continental belt:

1. This is the volcanic zone of convergent continental plate boundaries that includes the volcanoes of Alpine mountain chains, the Mediterranean Sea and the fault zone of eastern Africa.
2. The important volcanoes are Vesuvius, Stromboli, Etna, Kilimanjaro and Kenya.

3. Mid Atlantic Belt:

1. This belt represents the divergent boundary of plates located along the mid- Atlantic ridges. Volcanoes of this area are mainly of fissure eruption type.
2. St. Helena and Azores Island are other examples.

Question 2.
What are the causes of volcanic activity?
Answer:
Causes of Volcanic Activity

1. The temperature increases as the depth increases at the rate of l°c for every 35 metres.
2. There is also great pressure. At a depth of about 15 km the pressure is about 5 tonnes per cm of rock.
3. Under these circumstances, the interior of the earth is in a semi-molten state called magma.
4. The magma, under great pressure has the capacity to dissolve great volume of gas; some gases are also combustible.
5. This makes volcanic material burst forth through the weak spots in the earth’s crust.

Students can Download English Poem 1 Sea Fever Questions and Answers, Summary, Notes Pdf, Activity, Samacheer Kalvi 7th English Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 7th English Solutions Term 3 Poem Chapter 1 Sea Fever

Sea Fever Poem Line By Line Explanation By John Masefield, Sea Fever Exercise Question Answer.

Read And Understand

B. Choose the best answer

Sea Fever Poem 7th Standard Question 1.
The title of the poem ‘Sea Fever means _________
(a) flu fever
(b) the poet’s deep wish to be at sea
(c) the poet s fear of the sea
Answer:
(b) the poet’s deep wish to be at sea

Sea Fever Poem Questions And Answers Question 2.
The poet asks for _________
(a) a fishing net
(b) a big boat
(c) a tall ship
Answer:
(c) a tall ship

Sea Fever Questions Answers Question 3.
The poet wants to lead a life at sea like _________
(a) the gulls and whales
(b) the penguins and sharks
(c) the pelicans and dolphins
Answer:
(a) the gulls and whales

C. Read the lines and answer the questions.

Sea Fever Poem Questions And Answers Class 7 Question 1.
I must go down to the sea again, to the lonely sea and the sky
Where does the poet want to go?
Answer:
The poet wants to go to the sea again.

Sea Fever Poem Summary Question 2.
And the wheel’s kick and the winds song and the white sail’s shaking
What according to the poet are the pleasures of sailing?
Answer:
Will Watching from the shore, the wind’s song, the ship’s steering wheel and the shaking of the sail in the breeze are the pleasures of sailing.

Sea Fever Book Back Answers Question 3.
And all I ask is a windy day with the white clouds flying
Why does the poet ask for a windy day?
Answer:
The poet asks for a windy day, as it would blow away the thick white clouds from the sky and take the sail forward throughout the day.

Sea Fever Question Answer For Class 7 Question 4.
And all I ask is a merry yarn from a laughing fellow rover.
What kind of human company does the poet want?
Answer:
The poet wants the company of a fellow sailor or wanderer like him.

7th Standard English Sea Fever Question 5.
And quiet sleep and a sweet dream when the long trick’s over What does the poet want to do after his voyage is over?
Answer:
The poet wants to sleep soundly with pleasant dreams at the end of his long shift on watch.

D. Poem Appreciation

Sea Fever 7th Poem Question 1.
Fill in the blanks with correct rhyming words from the poem.
Answer:
sky – by, knife – life. rover – over.

Sea Fever Poem Question 2.
Quote the line that has been repeated in the poem.
Answer:
“I must go down to the seas again”.

Sea Fever Question And Answer Question 3.
Write the poetic device which is used in the line below.
And a grey mist on the sea’s face _________
Answer:
Imagery and personification.

7th English Poem Sea Fever Question 4.
What poetic device is used for the comparison in the below line?
Where the wind’s like a whetted life _________
Answer:
Simile

E. The poem has many visual and sound images. Complete the table with examples from the poem. The first one has been done for you.
Answer:

Visual images	Sound images
Wheels kick	Wind s song
white sail’s shaking	wild call
grey dawn	clear call
running tide	windy day
white clouds flying
blown spume
sea – gulls crying

Sea Fever Additional Questions

I. Poem Comprehension:

Sea Fever Poem Meaning In Tamil Question 1.
And all I ask is a tall ship and a star to steer her by;
What does the word ‘her’ refer to?
Answer:
‘Her’ refers to the tall ship.

Sea Fever Poem Summary 7th Standard Question 2.
To the gulls way and the whales way where the wind’s like a whetted knife;
What is like a whetted knife?
Answer:
The wind is strong like a whetted knife.

II. Poetic Devices:

Sea Fever Questions And Answers Question 1.
I must go down to the seas again, to the lonely sea and the sky,
Pick out the alliterated words.
Answer:
sea –sky are the alliterated words.

Sea Fever Summary In English Question 2.
And the wheel’s kick and the wind’s song and the white sail’s shaking,
What poetic device is used here?
Answer:
Personification: The wind, the wheel and the white sail are given the human qualities.

Sea Fever Question Answer Question 3.
And quiet sleep and a sweet dream when the long trick’s over.
Name the literary device used in this line.
Answer:
Metaphor : “when the long trick’s over’. This is comparing the end of a long voyage to the end of a long life.

III. Sea Fever Short Questions and Answers.

Question 1.
Why does the poet ask for a star?
Answer:
The poet asks for a star to guide the tall ship.

Question 2.
According to the poet, how is the call of the running tide?
Answer:
The call of the running tide is wild and clear.

Question 3.
What does the word ‘vagrant’ mean?
Answer:
‘Vagrant’ means wandering.

Question 4.
What does he want from a fellow-wanderer?
Answer:
He wants to share a happy tale and laughter with a fellow-wanderer.

Question 5.
What does the word ‘trick’ in sailing terms refer to?
Answer:
It refers to ‘a watch at sea’.

IV. Paragraph Question with Answer.

Question 1.
What message does the poet convey through the poem?
Answer:
John Masefield’s poem ‘Sea Fever’ is a work of art that brings beauty to the English language through its use of rhythm, imagery and many complex figures of speech. The imagery in ‘Sea Fever’ suggests an adventurous ocean that appeals to all five senses. Along with an adventurous ocean, ‘Sea Fever’ also sets a mood of freedom through the imagery of travelling gypsies. ‘Sea Fever’ not only depicts a strong longing for the sea through its theme, but also through the use of complex figures of speech.

Warm Up

Rescue the sinking words!

Answer:

1. Voyage
2. Vaves
3. Island
4. Navigate
5. Sailor
6. Explore
7. Harbour
8. Shore

Sea Fever Summary

In the poem ‘Sea Fever’, the poet, John Masefield expresses his desire for sailing once again in the quiet sea, under the quiet sky. He expresses his desire for the need of a well-built ship to sail and a star in the dark sky to act as a guide. Soon the adventures would begin and as each day dawns, he wakes up to see the early grey mist rise from the sea. He wishes that there would be strong winds that would blow away the thick white clouds in the sky and take sail forward throughout the day. Watching from the shore, fills his heart with the adventure and spirit. The poet finally wishes to be a wandering gypsy.

He loves to share the tales and laughter with a fellow sailor. He wanted to sleep soundly with pleasant dreams at the end of his long shift on watch.

Students can Download Science Chapter 5 Reproductive and Modification In Plants Questions and Answers, Notes Pdf, Samacheer Kalvi 7th Science Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 7th Science Solutions Term 1 Chapter 5 Reproductive and Modification In Plants

Samacheer Kalvi 7th Science Reproductive and Modification In Plants Textual Evaluation

I. Choose the appropriate answer :

Reproduction And Modification In Plants Question 1.
Vegetative propagation by leaves takes place in
(a) Bryophyllum
(b) Fungi
(c) Virus
(d) Bacteria
Answer:
(a) Bryophyllum

Reproduction And Modification In Plants 7th Standard Question 2.
Asexual reproduction in yeast is
(a) Spore formation
(b) Fragmentation
(c) Pollination
(d) Budding
Answer:
(d) Budding

Reproduction And Modification In Plants 7th Standard Book Back Answers Question 3.
Reproductive part of a plant is
(a) Root
(b) Stem
(c) Leaf
(d) Flower
Answer:
(d) Flower

Samacheer Kalvi Guru 7th Science Question 4.
Pollinators are
(a) Wind
(b) Water
(c) Insect
(d) All the above
Answer:
d) All the above

Climbing Roots Are Seen In Black Pepper Question 5.
Climbing roots are seen in
(a) Betel
(b) Black pepper
(c) Both of them
(d) None of them
Answer:
(c) Both of them

II. Fill in the blanks :

1. The male reproductive part of a flower is __________
2. __________ is the basal swollen part of the Gynoecium.
3. After fertilization the ovule becomes __________
4. Breathing roots are seen in __________ plants.
5. Onion and Garlic are example of __________

Answer:

1. Androecium
2. Ovary
3. seed
4. mangrove
5. Bulb

III. True (or) False, unrite the correct answer for the false statement.

Climbing Roots Are Seen In Betel Question 1.
A complete flower has four whorls.
Answer:
True

Question 2.
The transfer of pollen to the stigma is known as pollination.
Answer:
True

Question 3.
Conical shaped root is carrot.
Answer:
True

Question 4.
Ginger is an underground root.
Answer:
(False) Correct Statement: Ginger is an underground stem.

Question 5.
Leaves of Aloe vera are fleshy and store water.
Answer:
True

IV. Match the following :

1.	Petal	(a)	Opuntia
2.	Fern	(b)	Chrysanthemum
3.	Phylloclade	(c)	Attracts insect
4.	Hooks	(d)	Spore
5.	Sucker	(e)	Bignonia

Answer:

1. c
2. d
3. a
4. e
5. b

V. Very short answers.

Question 1.
Write two types of reproduction in plants.
Answer:
Sexual and Asexual Reproduction.

Question 2.
What are the two important parts of a flower?
Answer:
Androecium and Gynoecium.

Question 3.
Define – pollination.
Answer:
Transfer of pollen grains from the anther to stigma is called pollination.

Question 4.
What are the agents of pollination?
Answer:
Insects, wind, water, animals.

Question 5.
Give example for
(a) Corm
(b) Tuber
Answer:

1. Corm-e.g Colocasia
2. Tuber – e.g Potato.

Question 6.
What is tendril?
Answer:

1. It is an elongated structure produced by the plant to help the plants to climb efficiently.
2. e.g In pea, the terminal leaflets are modified into a tendril.

Question 7.
What are thorns?
Answer:

1. Thoms are pointed and sharp structures formed in a plant.
2. Leaves other parts may be modified into thorns.
3. It helps the plant to safeguard itself from animals. Thoms may also help in climbing.

VI. Short answer.

Question 1.
Differentiate bisexual flower from unisexual flower.
Answer:

S. No.	Bisexual flower	Unisexual flower
(a)	It has Androecium and Gynoecium	It has only Androecium or Gynoecium
(b)	It can undergo self pollination and cross pollination e.g : Hibiscus	They can be pollinated only by cross pollination eg : papaya.

Question 2.
What is cross pollination?
Answer:

1. Pollen grains are transferred from the anther of one flower to the stigma of another flower of the same kind or different plant.
2. Plants need to produce pollen grains in larger quantities to increase the chance of pollination.
3. Cross pollination does introduce variations in characteristics of new plants.
4. Cross pollination is brought about by agencies like wind, water, animals and Insects of plums, apples.

Question 3.
Write notes on phyllode.
Answer:
In Acacia auriculiformis, petioles expand to form leaf like structure. They carry out the function of leaf (Photosynthesis).

VII. Answer in Details.

Question 1.
Write a brief account on pollination.
Answer:
Transfer of pollen grains from the anther to the stigma is called pollination. There are two types of Pollination.
(a) Self Pollination
(b) Cross Pollination

(a) Self pollination

1. Pollen grains are transferred from the anther to the stigma of the same flower or to another flower of the same plant.
2. Plants do not need to produce pollen grains in a large quantity for self pollination.
3. It does not produce changes in the characteristics of new plants

(b) Cross Pollination

1. Pollen grains are transferee! for the anther of one flower to the stigma of anoter flower of the same kind or different plant.
2. Plants need to produce pollen grains in larger quantities to increase the chance of pollination.
3. Cross pollination does introduce variations in characteristics of new plants, e.g (apples, plums)
4. Agents like wind, water, insects and animals are helpful for pollination and are known as pollinators.
5. Wind pollinated plants produce pollen which are light. Insect pollinated flowers are brightly coloured and produce lot of pollen which sticks to the body of insects and are caused to other plants.
6. Pollination that occurs in nature is called Natural pollination.
7. Pollination between desired plants can be brought about by artificial methods.

Question 2.
Explain the underground stems.
Answer:
There are some stems that grow under the ground to store food. These underground stems swell and become thick.
There are four types of underground stems:

1. Rhizome.
2. Corm
3. Tuber
4. Bulb

(i) Rhizome : It is an underground thick stem with nodes and intemodes with scale , leaves at the node. It grows horizontally and has an irregular shape. Rhizome have buds. It gives rise to new stem and leaves. E.g. Ginger and Turmeric.

(ii) Corm: This underground stem is round in shape and flat at the top and bottom. It
is a condensed form of rhizome and bears one or more buds in the axils of scale leaves. Daughter plants arise from their buds. E.g. Colocasia.

(iii) Tuber: It is an enlarged, spherical underground stem that stores food. It has many dormant buds on its surface known as “Eyes”. If we plant a part of tuber with the bud, it grows into a new plant. E.g. Potato.

(iv) Bulb: It is condensed stem which is disc like and stores food in the fleshy leaves. The bulb has two types of leaves.

1. Fleshy Leaves
2. Scaly Leaves

The upper part of the stem has a terminal bud and it is covered by many scaly leaves, the inner fleshy leaves store food as seen in Garlic and Onion

VIII. Higher Order Questions :

Question 1.
Ginger is considered to be a stem, not a root. Why?
Answer:
Ginger has the following characteristics of a stem.

1. It has scale leaves
2. It has nodes and Intemodes
3. It has axillary buds and a terminal bud.
   Therefore Ginger is considered to be a stem but is is a modified underground stem which stores food.

Question 2.
What will happen if pollen grain of rose gets deposited on stigma of lily flower? Will pollen germination takes place? Why?
Answer:
No pollen of rose will get wasted and will not germinate on the stigma of lily flower. This is because pollen of a flower is compatible (match) only with stigma of a flower of the same species.

IX. Assertion and Reasoning types of Question :

Question 1.
Assertion : Pollination and fertilization in flowers, produces fruits and seeds. Reasoning :After fertilization the ovary becomes fruit and ovule becomes seed.
(a) Assertion is correct, Reasoning is incorrect
(b) Assertion is incorrect, Reasoning is correct
(c) Assertion is correct, Reasoning is correct
(d) Assertion is incorrect, Reasoning is incorrect
Answer:
(c) Assertion is correct, Reasoning is correct.

Question 2.
Assertion : The example of conical root is carrot.
Reasoning : It is an adventitious root modification.
(a) Assertion is incorrect, Reasoning is correct.
(b) Assertion is incorrect, Reasoning is incorrect
(c) Assertion is correct, Reasoning is correct
(d) Assertion is correct, Reasoning is incorrect
Answer:
(a) Assertion is incorrect, Reasoning is correct.

X. Picture Based question.

Question 1.
Observe the picture and draw the labels.
Parts of a Flower
Label the parts below :

Answer:

1. Stigma
2. Pistil
3. Filament
4. Ovule
5. Sepal
6. Stamen

Question 2.
Identify the four plants shown in the following Name the different modification in each of them.

	Name	Modification
1.	Garlic
2.	Turnip
3.	Rose plant

Answer:

	Name	Modification
1.	Garlic	Underground stem modification
2.	Turnip	Top Root modified for storage (Top shaped)
3.	Rose plant	Stem used for vegetative propagation / Asexual Reproduction by cutting
4.	Maize	Stilt Roots (Adventitious roots produced from the node for mechanical support).

Samacheer Kalvi 7th Science Reproductive and Modification In Plants Intext Activities

Activity 1

Using the information from the above complete the following table:

SI.No.	Name of the flower	Complete / incomplete	Unisexual / bisexual	If unisexual male or female
1.	Hibiscus	Complete	Bisexual	Both male & female present is same flower
2­	Pumpkin	Incomplete	Unisexual	Male in separate single flower & female in separate single flower
3.	Rose	Complete	Bisexual	Both male & female present is same flower
4.	Coconut	Incomplete	Unisexual	Male in separate single flower & female in separate single flower
5.	Jasmine	Complete	Bisexual	Both male & female present is same flower

Samacheer Kalvi 7th Science Reproductive And Modification Additional Questions

I. Choose the appropriate answer.

Question 1.
___________ do not produce spores.
(a) Algae
(b) Fungi
(c) Datura
(d) Ferns
Answer:
(c) Datura

Question 2.
___________ have the smallest seeds in the plant kingdom.
(a) Coconut
(b) Orchids
(c) Onion
(d) Pumpkin
Answer:
(b) Orchids

Question 3.
Breathing Roots are seen in ___________
(a) Tarpa
(b) Avicennia
(c) Eicchomia
(d) pisum
Answer:
(b) Avicennia

Question 4.
___________ is a parasite.
(a) Cuscuta
(b) Hibiscus
(c) yeast
(d) Spirogyra
Answer:
(a) Cuscuta

Question 5.
In ___________ sepal is seen on the fruit after fertilization
(a) Brinjal
(b) Pumpkin
(c) Onion
(d) Garlic
Answer:
(a) Brinjal

II. Fill in the Blanks.

1. The tissue seen in epiphytic roots is called _________
2. Cactus is a example for _________
3. Ginger and _________ are examples of Rhizome.
4. In Gloriosa _________ is modified into a tendil leaf tip.
5. Spirogyra reproduces by _________

Answer:

1. Velamen
2. Phylloclade
3. Turmeric
4. leaf tip
5. fragmentation

III. True or False – if false give the correct statement.

Question 1.
In cactus stem is modified into spines.
Answer:
(False) In cactus, leaf is modified into spines

Question 2.
Ovules fall off after fertilization.
Answer:
(False) Style and stigma fall off after fertilization.

Question 3.
In Nepenthes, leaf is modified into a flask shaped structure.
Answer:
True

Question 4.
Tuber is an enlarged underground root.
Answer:
(False) Tuber is an enlarged underground stem.

Question 5.
Scaly leaves are seen in onion.
Answer:
True

IV. Match the following :

Question 1.

Vanda	(a)	Climber
Pea	(b)	epiphyte
Eicchomia	(c)	offset
wild strawberry	(d)	Runner stolon

Answer:

1. b
2. a
3. c
4. d

Question 2.

Pollen	(a)	anther
Ovule	(b)	protection
stamen	(c)	Powdery
Sepal	(d)	Seed

Answer:

1. c
2. d
3. a
4. b

V. Assertion and Reason types of Question.

(a) Assertion is correct, Reason is incorrect
(b) Assertion is incorrect, Reason is correct
(c) Assertion is correct, Reason is correct
(d) Assertion is incorrect, Reason is incorrect

Assertion : In potato shoot arises from eyes.
Reason : Eyes represent the buds.
(c) Assertion is correct, Reasoning is correct.

Assertion : In Banyan prop roots grow horizontally from the tree.
Reason : They give additional support to the tree.
(b) Assertion is incorrect, Reasoning is correct.

Assertion : Corm is a condensed form of Bulb.
Reason : It has dry and fleshy scale leaves.
(d) Assertion is incorrect, Reasoning is incorrect.

VI. Find the odd one out.

Question 1.
Pollen, anther, ovule, filament Ovule
Reason : It is a part of Gynoecium whereas others are parts of Androecium.

Question 2.
Corm, Bulb, Rhizome, sucker
Answer:
Sucker
Reason : It is a sub aerial stem modification whereas others are underground stem modification.

Question 3.
Haustoria, Velamen, Prop Roots, Phylloda.
Answer:
Phylloda
Reason : It is a leaf modification whereas others are root modifications.

VII. Complete the table

Question 1.

Underground stem	_____(1)_____	Ginger
_____(2)_____	Runner	_____(3)_____
Leaf modification	_____(4)_____	Acacia
Root modification	sucking Roots	_____(5)_____

Answer:

1. Rhizome
2. Sub aerial stem
3. Centella
4. phylloda
5. Cuscuta.

Question 2.

Caly x	_____(1)_____	_____(2)_____
_____(3)_____	petal	attract insects
Androecium	_____(4)_____	Male reproductive part
_____(5)_____	_____(6)_____	Female reproductive part.

Answer:

1. sepal
2. protection
3. corolla
4. stamen
5. Gynoecium
6. Ovary, style, stigma.

VIII.Very short answers:

Question 1.
Name the whorls of a flower
Answer:
Calyx, corolla, Androecium and Gynoecium.

Question 2.
What is an inflorescence?
Answer:
A group of flowers is called an inflorescence, e.g sunflower.

Question 3.
What is fertilization.
Answer:
Male gamete fuses with the female gamete to form zygote. This process is known as fertilization.

Question 4.
Name the sub aerial modifications of stem.
Answer:
Runner, stolum, sucker, offset.

Question 5.
Name the underground stem modifications.
Answer:
Rhizome, Corm, Tuber, Bulb.

Question 6.
What are sucking Roots?
Answer:

1. Sucking roots (or) Haustoria are found in parasite plants.
2. These roots penetrate the tissues of host plant and suck nutrients from then, e.g cuscuta.

Question 7.
Differentiate Phyllode and Phylloclade.
Answer:

Phyllode	Phylloclade
Petioles are modified to form leaf like structure, e.g. Acacia.	stem is modified to form leaf like structure, e.g. Cactus.

Question 8.
What are breathing Roots or Pneumatophores?
Answer:

1. Mangrove plants roots which are seen above the ground for the purpose of gaseous exchange.
2. These roots are erect, peg like structures with numerous pores through which air circulates.
3. These roots are called breathing roots, or pneumatophores. e.g Avicennia.

IX. Short answers.

Question 1.
List the post fertilization changes in a flower.
Answer:

1. Calyx sometimes persist with fruit
2. Petals wither / fall off
3. Androecium fall off
4. Pistil remain and develops into a fruit
5. Style and stigma fall off
6. Ovary enlarges to store food materials and develops into a fruit.
7. Ovules present inside the ovary develops into seeds.

Question 2.
Write a note an roots modified for mechanical support.
Answer:
Many Plants require additional support. Such plants develop roots on their aerial parts to provide mechanical support. These roots grow downward and act as supportive organs. There are three types of modified roots for support.

1. Prop roots : Roots are modified to provide mechanical support as seen in Banyan tree. These roots grow vertically from horizontal branches of a tree.
2. Stilt roots : In sugarcane, and maize adventitious roots arise from the nodes in cluster at the base of the stem. These roots are called stilt roots which gives additional support.
3. Climbing roots : In betel and black pepper, nodes or intermodes bear roots which help in climbing.

Question 3.
How do Epiphytic roots differ from Sucking roots?
Answer:

Epiphytic roots	Sucking roots
Vanda is an epiphytic plant, which grows on trees. The velamen tissue present in the epiphytic root, absorbs moisture, to perform photosynthesis.	Cuscuta a parasite plant, climb the trees and other vegetation and use the haustorial roots Sucking roots to penetrate the tissue of the host plant and suck nutrients from them. They are usually found in parasitic plants that depend on the host plants for nutrients.

Question 4.
Write a note on phylloclade.
Answer:

1. Plants growing in deserts try to store water. If the surface area is large, more water is lost by evaporation.
2. In plants like cactus, the stem is thick and becomes flat like leaves to do photosynthesis.
3. The leaves are reduced to small spines with less surface area. This kind of modification is called phylloclade. e.g. cactus.

Question 5.
What are traps or Insectivorous plants?
Answer:

1. These plants grow in nitrogen deficient places. In Nepenthes, the leaves are modified into a flask like structure, which is used to attract insects and other tiny animals.
2. The inner wall of the leaf secretes digestive enzymes that help to digest the insects and extract the nitrogen needed for the plant. E.g: Nepenthes.

Question 6.
Differentiate self pollination and cross pollination.
Answer:

S.no	Self pollination	Cross pollination
1.	Pollen grains are transferred from the anther to the stigma of the same flower or to another flower of the same plant.	Pollen grains are transferred from the anther of one flower to the stigma of another flower of the same kind or different plant.
2.	Plants do not need to produce pollen grains in a large quantity for self pollination	Plants need to produce pollen grains in larger quantities to increase the chance of pollination.
3.	It does not produce changes in the characteristics of new plants.	Cross pollination does introduce variations in characteristics of new plants.

Question 7.
Identify the plant and the modification seen in it
.
Answer:
Chrysanthemum
Modification : Sucker (sub aerial stem modification).

X. Answer in detail

Question 1.
Write a note an sub aerial modifications of the stem.
Answer:
Sub- aerial Modifications : Stem of some plants remains sub- aerial which grow horizontally on the surface of the soil for the purpose of reproduction. There are four types.

1. Runner: The stem grows laterally on the surface of the soil, breaks up to produce roots where it touches the ground to give rise to new plants. Eg: Centelk (Vallarai).
2. Stolon: Stolon is a slender branch of the stem that grows upwards to some distance and then bends towards the ground. Upon touching the ground, it gives rise to a new plant. Eg. Wild strawberry.
3. Sucker Sucker is a short and weak lateral branch that grows diagonally upwards and directly gives rise to a new shoot. Eg. Chrysanthemum.
4. Offset: An offset is a short and thick branch that arises from the axial part of a leaf. It has thick intemodes. It produces a tuft of leaves and cluster of small roots below. Eg: Eichhornia.

Question 2.
Draw a diagram to show the life cycle of a plant.
Answer:

XI. Higher Order Questions : (HOTS)

Question 1.
Parasitic plants lack leaves.
Answer:
Parasites are plants which live on other living plants and derive nutrients from them. They are non-green and do not photosynthesize. They have sucking roots to absorb the nutrients directly from the host tissue. Thus they lack leaves.

Students can Download Tamil Chapter 2.5 ஒரெழுத்து ஒருமொழி, பகுபதம், பகாப்பதம் Questions and Answers, Summary, Notes Pdf, Samacheer Kalvi 7th Tamil Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 7th Tamil Solutions Term 2 Chapter 2.5 ஒரெழுத்து ஒருமொழி, பகுபதம், பகாப்பதம்

மதிப்பீடு

சரியான விடையைத் தேர்ந்தெடுத்து எழுதுக.

Question 1.
நன்னூலின்படி தமிழிலுள்ள ஓரெழுத்து ஒரு மொழிகளின் எண்ணிக்கை …………..
அ) 40
ஆ) 42
இ) 44
ஈ) 46
Answer:
ஆ) 42

Question 2.
எழுதினான்’ என்பது ………………..
அ) பெயர்ப் பகுபதம்
ஆ) வினைப் பகுபதம் இ) பெயர்ப் பகாப்பதம்
ஈ) வினைப் பகாப்பதம்
Answer:
ஆ) வினைப் பகுபதம்

Question 3:
பெயர்ப்ப குபதம் ……………… வகைப்படும்.
அ) நான்கு
ஆ) ஐந்து
இ) ஆறு
ஈ) ஏழு
Answer:
இ) ஆறு

Question 4.
காலத்தைக் காட்டும் பகுபத உறுப்பு ……………….
அ) பகுதி
ஆ) விகுதி
இ) இடைநிலை
ஈ) சந்தி
Answer:
இ) இடைநிலை

பொருத்துக

1. பெயர்ப் பகுபதம் – வாழ்ந்தான்
2. வினைப் பகுபதம் – மன்
3. இடைப் பகாப்பதம் – நனி
4. உரிப் பகாப்பதம் – பெரியார்
Answers:
1. பெயர்ப் பகுபதம் – பெரியார்
2. வினைப் பகுபதம் – வாழ்ந்தான்
3. இடைப் பகாப்பதம் – மன்
4. உரிப் பகாப்பதம் – நனி

சரியான பகுபத உறுப்பை எழுதுக

1. போவாள் – போ + வ் + ஆள்
போ – பகுதி
வ் – எதிர்கால இடைநிலை
ஆள் – படர்க்கைப் பெண்பால் வினைமுற்று விகுதி

2. நடக்கின்றான் – நட + க் + கின்று + ஆன்
நட – பகுதி
க் – சந்தி
கின்று – நிகழ்கால இடைநிலை
ஆன் – படர்க்கை ஆண்பால் வினைமுற்று விகுதி

பின்வரும் சொற்களைப் பிரித்துப் பகுபத உறுப்புகளை எழுதுக

1. பார்த்தான் – பார் + த் + த் + ஆன்
பார் – பகுதி
த் – சந்தி
த் – இறந்தகால இடைநிலை
ஆன்- படர்க்கை ஆண்பால் வினைமுற்று விகுதி

2. பாடுவார் – பாடு + வ் + ஆர்
பாடு – பகுதி
வ் – எதிர்கால இடைநிலை
ஆர் – படர்க்கைப் பலர்பால் வினைமுற்று விகுதி

குறுவினா

Question 1.
ஓரெழுத்து ஒருமொழி என்றால் என்ன?
Answer:
(i) ஓரெழுத்து தனித்து நின்று பொருள் தரும் சொல்லாக அமைவதே ஓரெழுத்து ஒரு மொழி ஆகும்.
(ii) எ.கா. (தீ, நீ, வா, போ).

Question 2.
பதத்தின் இரு வகைகள் யாவை?
Answer:
பதம் இரண்டு வகைப்படும். அவை, பகுபதம், பகாப்பதம்.

Question 3.
பகுபத உறுப்புகள் எத்தனை வகைப்படும்?
Answer:
அவை யாவை? பகுபத உறுப்புகள் ஆறு வகைப்படும். அவை, பகுதி, விகுதி, இடைநிலை, சந்தி, சாரியை, விகாரம்.

சிறுவினா

Question 1.
விகுதி எவற்றைக் காட்டும்?
Answer:
சொல்லின் இறுதியில் நிற்கும் உறுப்பே விகுதி ஆகும். இது திணை, பால், எண், இடம்,
முற்று, எச்சம் போன்றவற்றைக் காட்டும். (எ.கா.) படித்தான் = ஆன் – விகுதி

Question 2.
விகாரம் என்பது யாது? எடுத்துக்காட்டுடன் விளக்குக.
Answer:
பகுதி, விகுதி, சந்தி, இடைநிலை இவற்றில் ஏற்படும் மாற்றமே விகாரம் எனப்படும்.
(எ. கா.) வந்தான் = வா – பகுதி வா ‘வ’ எனக் குறுகியது விகாரம்.

Question 3.
பெயர்ப்பகுபதம் எத்தனை வகைப்படும்? அவை யாவை?
Answer:
பெயர்ப் பகுபதம் ஆறு வகைப்படும். அவை
(i) பொருள் – பொன்னன் (பொன் + அன்)
(ii) இடம் – நாடன் (நாடு + அன்)
(iii) காலம் சித்திரையான் (சித்திரை + ஆன்)
(iv) சினை கண்ண ன் (கண் + அன்)
(v) பண்பு இனியன் (இனிமை + அன்)
(vi) தொழில் – உழவன் (உழவு + அன்)

கற்பவை கற்றபின்

Question 1.
பாடப்பகுதியில் இடம்பெற்ற சொற்களில் பகுபதம், பகாப்பதம் ஆகியவற்றைக் கண்டறிந்து தனித்தனியே தொகுக்க.
Answer:
பகுபதம்
பெயர்ப்பகுபதம் :
பொருள் – பொன்னன் (பொன் + அன்)
இடம் – நாடன் (நாடு + அன்)
காலம் – சித்திரையான் (சித்திரை + ஆன்)
சினை – கண்ண ன் (கண் + அன் )
பண்பு – இனியன் (இனிமை + அன்)
தொழில் – உழவன் (உழவு + அன்)
வினைப்பகுபதம் : உண்கின்றான் – உண் + கின்று + ஆன்

பகாப்பதம் :
பெயர்ப் பகாப்பதம் – நிலம், நீர், நெருப்பு, காற்று
வினைப் பகாப்பதம் – நட, வா, படி, வாழ்.
இடைப் பகாப்பதம் – மன், கொல், தில், போல்
உரிப் பகாப்பதம் – உறு, தவ, நனி, கழி.

Question 2.
உங்கள் வகுப்பு மாணவ – மாணவிகளின் பெயர்களைப் பகுபதம், பகாப்பதம் என வகைப்படுத்துக.
Answer:
மாணவர்கள் தாங்களாகவே செய்ய வேண்டியவை.

கூடுதல் வினாக்கள்

நிரப்புக.

Question 1.
தே என்பதன் பொருள் ………….. எனப்படும்.
Answer:
கடவுள்

Question 2.
நன்னூல் என்னும் இலக்கண நூலை எழுதியர் ………….
Answer:
பவணந்தி முனிவர்

ஓரெழுத்து ஒரு மொழிகளும் அவற்றின் பொருளும்

மொழியை ஆள்வோம்

கேட்க.

Question 1.
சிறந்த கல்வியாளர்களின் சொற்பொழிவுகளை இணையத்தில் கேட்டு மகிழ்க.
Answer:
மாணவர்கள் தாங்களாகவே செய்ய வேண்டியவை

கீழ்க்காணும் தலைப்பில் இரண்டு நிமிடம் பேசுக

Question 1.
கல்வியின் சிறப்பு
Answer:
அனைவருக்கும் வணக்கம்!
நான் கல்வியின் சிறப்பு என்ற தலைப்பில் பேசவிருக்கிறேன். இன்றைய உலகின் தே இன்றியமையாத ஒன்றாகத் திகழ்வது யாதெனில் கல்வியே ஆகும். அனைவருக்கும் பகுத்தறிவு தேவைப்படுகிறது. அவர்களுக்குப் பகுத்தறியும் சக்தியைக் கொடுப்பதே கல்வியின் சிறப்பாகும்.

கல்வியின் சிறப்பு என்றாலே கல்வி கற்றவன் எங்குச் சென்றாலும் சிறப்பிக்கப்படுபவன் – என்பதே நினைவுக்கு வரும். அவனுக்கு எல்லா நாட்டினரும் உறவினர்கள் ஆவார்கள். எல்லா நாடும் சொந்த நாடாகும். கல்வி கற்கவில்லையெனில் வாழ்நாள் முழுவதும் அனைவராலும் அவமதிக்கப்படுவான். இதனையே வள்ளுவர்.

“யாதானும் நாடாமல் ஊர்ஆமால் என்னொருவன் சாந்துணையும் கல்லாத வாறு. என்று கூறுகிறார்.
அதுமட்டுமா? கற்றவரைக் கண்ணுடையார்’ என்றும் கல்லாதவரை முகத்தில் இரண்டு புண்ணுடையவர் என்றும் இடித்துரைக்கிறார் வள்ளுவர்.

கற்றோர்க்கு அணிகலன் கல்வியே; கற்றோரே கண்ணுடையவர்; கற்றாரே தேவர் எனப் போற்றப்படத்தக்கவர்; கற்றோரே மேலானவர் என்பதை அனைவரும் உணர வேண்டும்.
“கல்வி வந்தது எனில் கடைத்தேறிற்று உலகே!” என்று புரட்சிக்கவி கூறுகின்றார். கல்வியால் எல்லா வளங்களும் கிடைக்கும் என்பதே இதன் பொருளாகும்.

கல்வி உடையவர் எல்லா மக்களிடமும், நன்றாக பழகிக் கொள்வதோடு மட்டுமல்லாமல் அவர்களுடன் மகிழ்ச்சியாக சேர்ந்து வாழ்வதையே விரும்புவர்.

மனிதன் வாழ்நாள் முழுவதும் கற்றுக் கொண்டே இருக்க வேண்டும். கற்க மறுப்பவன் வாழ மறுப்பவன் ஆகின்றான். கல்வி என்னும் விளக்கால் வாழ்க்கையில் எதிர்ப்படும் இருள்களையெல்லாம் நீக்க முடியும். கல்வி போல மனப்பயத்தைப் போக்கும் மருந்து வேறொன்றுமில்லை. கல்வித் துணை வறுமையில் கை கொடுக்கும். கல்வியின் பயனே மனித வாழ்வின் பெரும்பேறாகும்.

கல்வி, தொழிலுக்கு வழி காட்டும். கல்வி என்பது வாழ்வதற்கு உதவும் கருவியாகும். வாழ்க்கையின் வெற்றிக்குக் கல்வி மிகவும் இன்றியமையாததாகிறது. வாழ்க்கையை நெறிப்படுத்தவும் மேம்படுத்தவும் கல்வி பயன்படுகிறது. கல்வி கற்ற பண்பு, நீதி, நேர்மை இவைகள் அனைத்தும் ஒருங்கே அமைந்து காணப்படும்.

கல்வியினால் மட்டுமே உலக அறிவினை வளர்த்துக் கொள்ள முடியும். உலகை முழுமையாகப் படிக்கவும் முடியும். கல்வி மனிதனுக்கு ஓர் உன்னதமான தேவையாகும்”
“கற்கை நன்றே! கற்றை நன்றே! பிச்சைப் புகினும் கற்கை நன்றே!” என்ற கூற்றினை மனதில் நிறுத்தி அள்ள அள்ளக் குறையாதக் கல்வியை அள்ளிப் பருகுவோம்.
கல்வி என்பது பலமே !
கற்றல் என்பது சுகமே!

Question 2.
குழந்தைத் தொழிலாளர் முறை ஒழிப்பு
Answer:
ஒரு குழந்தை கூலிக்காக வேலை பார்ப்பது மிகவும் தவறு. இளமைக் காலம் கல்வி கற்பதற்கே. குழந்தைத் தொழிலாளர்கள் இல்லாத நிலை உருவாக வேண்டும்.
பள்ளி செல்லாத குழந்தைகள், குழந்தைத் தொழிலாளர் ஆகிறார்கள். இது ஒரு பக்கம் இருக்க; வேலைவாய்ப்புக்காக இடம்பெயர்ந்து மாநிலம் விட்டு மாநிலம், மாவட்டம் விட்டு மாவட்டம் என்று செல்கின்றனர். இவ்விரண்டு நிலைகளில் ஒரு சிலர் தங்கள் பெற்றோருடன் சேர்ந்து வேலை செய்வார்கள் அல்லது தனியாகச் செல்வார்கள்.

மூன்றாவது நிலையில் உள்ளவர்கள் மிகவும் பரிதாபத்துக்குரியவர்கள். கொத்தடிமை முறையில் வேலைக்குச் செல்கிறார்கள். பெற்றோர் வாங்கிய கடனை ஈடுகட்டுவதற்காக பிள்ளைகள் வேலைக்குச் செல்கிறார்கள்.

குழந்தைத் தொழிலாளர்கள் உடல் ரீதியாகப் பாதிக்கப்படுகிறார்கள். உளவியல் ரீதியான பாதிப்பு, உணர்வு மற்றும் சமூக ரீதியான பாதிப்பு ஏற்படுகிறது.

கொடிய வறுமை, ஊட்டச்சத்துக் குறைவு, கல்வியறிவு பெற முடியாத நிலை, உடல் நலனைப் பாதிக்கக் கூடிய ஆபத்தான சூழல், காற்றோட்டம் இல்லாத குறுகிய அறை போன்றவை குழந்தைகளின் உடல் நலனைப் பெரிதும் பாதிப்பதால் ஆஸ்துமா, காசநோய் போன்ற நோய்கள் தாக்குகிறது. இதனைத் தடுக்க வேண்டும்.

குழந்தைகளுக்குத் தொடக்கக் கல்வி கட்டாயம் ஆக்கப்பட வேண்டும். பள்ளி மற்றும் கல்லூரிகளில் குழந்தைத் தொழிலாளர் ஒழிப்பு பற்றிய விழிப்புணர்வு முகாம்களை நடத்தலாம்.

சொல்லக் கேட்டு எழுதுக

1. இளமைப் பருவத்திலேயே கல்வி கற்க வேண்டும்.
2. கல்வியே அழியாத செல்வம்.
3. கல்வி இல்லாத நாடு விளக்கு இல்லாத வீடு.
4. பள்ளித்தலம் அனைத்தும் கோயில் செய்குவோம்.
5. நூல்களை ஆராய்ந்து ஆழ்ந்து படிக்க வேண்டும்.

கீழ்க்காணும் சொற்களை அறுவகைப் பெயர்களாக வகைப்படுத்துக

நல்லூர், வடை, கேட்டல், முகம், அன்னம், செம்மை, காலை, வருதல், தோகை, பாரதிதாசன், பள்ளி, இறக்கை, பெரியது, சோலை, ஐந்து மணி, விளையாட்டு, புதன்

Answer:

அறிந்து பயன்படுத்துவோம்

மூவிடம் :

இடம் மூன்று வகைப்படும். அவை 1. தன்மை, 2. முன்னிலை, 3. படர்க்கை
தன்னைக் குறிப்பது தன்மை.
(எ.கா.) நான், நாம், நாங்கள், என், எம், எங்கள்.
முன்னால் இருப்பவரைக் குறிப்பது முன்னிலை.
(எ.கா.) நீ , நீங்கள், நீர், நீவிர், உன், உங்கள்.
தன்னையும், முன்னால் இருப்பவரையும் அல்லாமல் மூன்றாமவரைக் குறிப்பது – படர்க்கை .
(எ.கா.) அவன், அவள், அவர், அவர்கள், அது, அவை, இவன், இவள், இவை.

சரியான சொல்லைக் கொண்டு நிரப்புக

(அது, நீ, அவர்கள், அவைகள், அவை, நாம், உன்)

Question 1.
……… பெயர் என்ன ?
Answer:
உன்

Question 2.
ஏழாம் வகுப்பு மாணவர்கள்.
Answer:
நாம்

Question 3.
………….. எப்படி ஓடும்?
Answer:
அது

Question 4.
………………என்ன செய்து கொண்டிருக்கிறாய்?
Answer:
நீ

Question 5.
…. வந்து கொண்டு இருக்கிறார்கள்.
Answer:
அவர்கள்

பின்வரும் தொடர்களில் மூவிடப் பெயர்களை அடிக்கோடிடுக. அவற்றை வகைப்படுத்துக.

1. எங்கள் வீட்டு நாய்க்குட்டி ஓடியது.
2. இவர்தான் உங்கள் ஆசிரியர்.
3. நீர் கூறுவது எனக்குப் புரியவில்லை
4. எனக்கு, அது வந்ததா என்று தெரியவில்லை , நீயே கூறு.
5. உங்களோடு நானும் உணவு உண்ணலாமா?

Answer:

கடிதம் எழுதுக

உங்கள் பகுதியில் நூலகம் ஒன்று அமைத்துத் தர வேண்டி நூலக ஆணையருக்குக் கடிதம் எழுதுக.
Answer:
அனுப்புநர் :
ஊர்ப் பொதுமக்கள்,
மறைமலை நகர்,
காஞ்சிபுரம் மாவட்டம்

பெறுநர் :
நூலக ஆணையர்,
பொதுநூலகத் துறை,
சென்னை – 600 002.

மதிப்பிற்குரிய ஐயா,
பொருள் : நூலகம் அமைத்துத் தர வேண்டுதல் தொடர்பாக

எங்கள் ஊர் மறைமலைநகர். இங்கு இரண்டாயிரம் பேருக்கு மேல் வாழ்கிறோம். பள்ளி மாணவர்கள், கல்லூரி மாணவர்கள், போட்டித் தேர்வுக்குப் படிக்கும் இளைஞர்கள், அன்றாடச் செய்தியை அறிந்து கொள்ளும் ஆர்வலர், பணி ஓய்வு பெற்றவர்கள் எனப் பலரும் உள்ளனர்.

அவரவர்களுக்குத் தேவையான நூல்கள், செய்தித்தாள்கள், இதழ்கள் போன்றவை இங்குக் கிடைப்பதற்கரிதாக உள்ளது. இவர்கள் அனைவரும் பயன்பெறும் வகையில் நூலகம் ஒன்றை எங்கள் ஊரில் அமைத்துத்தர ஆவன செய்யுமாறு கேட்டுக் கொள்கிறோம்.

நன்றி!
இடம் : மறைமலை நகர்,
தேதி : 5-2-2020

இப்படிக்கு ,
தங்கள் உண்மையுள்ள,
ஊர்ப் பொதுமக்கள்

மொழியோடு விளையாடு

கீழே உள்ள குறிப்புகளைப் பயன்படுத்திக் கட்டத்தில் எழுத்துகளை நிரப்புக.
1. காலையில் பள்ளி மணி……………………
2. திரைப்படங்களில் விலங்குகள் ……………………… காட்சி குழந்ை தகளுக்குப் பிடிக்கும்.
3. கதிரவன் காலையில் கிழக்கே ………………
4. நாள்தோறும் செய்தித்தாள் ………………. வழக்கம் இருக்க வேண்டும்.

Answer:

1. காலையில் பள்ளி மணி அடிக்கும்.
2. திரைப்படங்களில் விலங்குகள் நடிக்கும் காட்சி குழந்ை தகளுக்குப் பிடிக்கும்.
3. கதிரவன் காலையில் கிழக்கே உதிக்கும்.
4. நாள்தோறும் செய்தித்தாள் படிக்கும் வழக்கம் இருக்க வேண்டும்.

ஓர் எழுத்துச் சொற்களால் நிரப்புக

Question 1.
…………………… புல்லை மேயும்.
Answer:
ஆ

Question 2.
……………………… சுடும்.
Answer:
தீ

Question 3.
……………….. பேசும்.
Answer:
நா

Question 4.
…………………… பறக்கும்.
Answer:
ஈ

Question 5.
…………….. மணம் வீசும்
Answer:
பூ

பின்வரும் எழுத்துகளுக்குப் பொருள் எழுதுக

(எ.கா.) தா – கொடு

Answer:

1. தீ – நெருப்பு
2. பா – பாடல்
3. தை – தை மாதம்
4. வை – புல், வைக்கோல்
5. மை – அஞ்சனம்

பின்வரும் சொற்களை இருபொருள் தருமாறு தொடரில் அமைத்து எழுதுக

(ஆறு, விளக்கு, படி, சொல், கல், மாலை, இடி)
(எ.கா.) ஆறு – ஈ ஆறு கால்களை உடையது.
தஞ்சாவூரில் காவிரி ஆறு பாய்கிறது.

விளக்கு : இலக்கணப் பாடத்தை விளக்கிக் கூறு.
அறியாமை என்னும் இருளைப் போக்குவது கல்வி என்னும் விளக்கு.

படி : காலையில் தினமும் படி.
மாடிப்படி ஏறி வா.

சொல் : சொற்கள் சேர்ந்தால் பாமாலை.
பெரியோர் சொல் கேட்டு சிறியோர் நடக்க வேண்டும்.

கல் : கற்களால் ஆனது கோபுரம்.
இளமையில் கல்.

மாலை : நேற்று மாலை பூங்காவிற்குச் சென்றேன்.
பூ மாலை நல்ல மணம் வீசியது.

இடி இடிக்கும் சப்தம் கேட்டது.
தவறுகளைக் கண்டால் இடித்துரைத்தல் வேண்டும்.

நிற்க அதற்குத் தக

என் பொறுப்புகள்

1. பாடப்புத்தகங்கள் மட்டுமன்றிப் பிற புத்தகங்களையும் படிப்பேன்.
2. பெற்றோர், ஆசிரியர், மூத்தோர் இவர்களை எப்போதும் மதித்து நடப்பேன்.

கலைச்சொல் அறிவோம்

Students can Download Science Chapter 2 Force and Motion Questions and Answers, Notes Pdf, Samacheer Kalvi 7th Science Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 7th Science Solutions Term 1 Chapter 2 Force and Motion

Samacheer Kalvi 7th Science Force and Motion Textual Evaluation

I. Choose the appropriate answer :

Force And Motion Class 7 Question 1.
A particle is moving in a circular path of radius r. The displacement after half a circle would be
(a) Zero
(b) R
(c) 2r
(d) r/2
Answer:
(c) 2r

Force And Motion Class 7 Book Back Questions And Answers Question 2.
From the given v-t graph it can be inferred that the object is

(a) in uniform motion Time
(b) at rest
(c) in non uniform motion
(d) moving with uniform acceleration
Answer:
(d) moving with uniform acceleration

Force And Motion Class 7 Questions And Answers Question 3.
Which of the following figures represent uniform motion of a moving object correctly?

Answer:

Force And Motion 7th Standard Question 4.
Suppose a boy is enjoying a ride on a merry go round which is moving with a constant speed of 10 m/s. It implies that the boy is.
(a) at rest
(b) moving with no acceleration
(c) in accelerated motion
(d) moving with uniform velocity
Answer:
(c) in accelerated motion

7th Standard Science Force And Motion Question Answer Question 5.
What is one way you might increase the stability of an object?
(a) lower the centre of gravity
(b) raise the centre of gravity
(c) increase the height of the object
(d) shorten the base of the object
Answer:
(a) lower the centre of gravity

II. Fill in the blanks :

1. The shortest distance between the two places is _______
2. The rate of change of velocity is _______
3. If the velocity of an object increases with respect to time, then the object is said to be in _______ acceleration.
4. The slope of the speed-time graph gives _______
5. In _______ equilibrium its centre of gravity remains at the same height when it is displacement

Answer:

1. displacement
2. acceleration
3. positive
4. velocity
5. neutral

III. Match the following :

1.	Displacement	(a)	Knot
2.	Light travels through vacuum	(b)	Geometric centre
3.	Speed of ship	(c)	Metre
4.	Centre of gravity of the geometrical shaped object	(d)	Larger base area
5.	Stability	(e)	Uniform velocity

Answer:

1. c
2. e
3. a
4. d
5. b

IV. Analogy :

7th Science Force And Motion Question 1.
velocity : metre/ second :: acceleration : _______
Answer:
metre/second²

7th Standard Science Force And Motion Question 2.
length of scale : metre : : speed of aeroplane : _______
Answer:
knot

Samacheer Kalvi Guru 7th Science Question 3.
displacement / time : velocity : : speed / time : _______
Answer:
acceleration

V. Give very short answer :

Samacheer Kalvi 7th Science Books Answers Question 1.
All objects having uniform speed need not have uniform velocity. Describe with the help of examples.
Answer:
An object moving in uniform circular motion is moving around the perimeter of the circle with a constant speed. While the speed of object is constant, its velocity is changing, Ex: Merry-go-round, roller coaster, planets orbiting the sun.

Samacheer Kalvi 7th Books Science Question 2.
“She moves at a constant speed in a constant direction”. Rephrase the same sentence in fewer words using concepts related to motion.
Answer:
She moves in a straight line with constant velocity.

Samacheer Kalvi 7th Science Book Question 3.
Correct your friend who says “The acceleration gives the idea of how fast the position changes”.
Answer:
There are two possible answers:
Velocity gives an idea of how fast the position changes, or Acceleration gives an idea of how fast the velocity changes.

VI. Give Short Answer :

Samacheer Kalvi 7th Science Question 1.
Show the shape of the distance – time graph for the motion in the following cases.
a. A bus moving with a constant speed
b. A car parked on a road side.
Answer:
(a) A bus moving with constant speed.

(b) A car parked on road side

Science Samacheer Kalvi 7th Books Question 2.
Distinguish between speed and velocity.
Answer:

Samacheer Kalvi 7th Standard Science Question 3.
What do you mean by constant acceleration?
Answer:
A body is said to have constant acceleration, if it travels is a straight line and its velocity increases or decreases by equal magnitude in equal intervals of time.
Ex: the motion of a freely falling body.

Samacheer Kalvi 7th Science Book Answers Question 4.
What is centre of gravity ?
Answer:
The centre of gravity of an object is the point through which the entire weight of the object appears to act.

VII. Answer in detail.

Samacheer Kalvi 7th Science Book Back Answers Question 1.
Explain the types of stability with suitable examples.
Answer:
Stability is a measure of the body’s ability to maintain its original position.
The three types of stability are

1. Stable equilibrium
2. Unstable equilibrium
3. Neutral equilibrium

Stable Equilibrium:
The frustum can be tilted through quite a big angle without toppling.

Its centre of gravity is raised when it is displaced. The vertical line through its centre of gravity still falls within its base. So it can return to its originalposition.

Unstable Equilibrium:
The frustum will topple with the slightest tilting. Its centre of gravity is lowered when it is displaced.

The vertical line through its centre of gravity falls outside its base.

Neutral Equilibrium:

1. It causes frustum to topple.
2. The frustum will roll about but does not topple.
3. Its centre of gravity remains at the same height when it is displaced.
4. The body will stay in any position to which it has been displaced.

Samacheer Kalvi 7th Standard Science Book Question 2.
Write about the experiment to find the centre of gravity of the irregularly shaped plate.
Answer:

1. Make three holes in the lamina.
2. Suspend the lamina from the optical pin through one of the holes
   
3. Suspend the plumb line from the pin and mark the position of the plumb line on the lamina’
4. Draw lines on the lamina representing the positions of the plumb line.
5. Repeat the above steps for the holes.
6. Label the intersection of the three lines as X, the position of the center of gravity of the lamina.

VIII. Numerical problems:

Samacheer Kalvi Science 7th Standard Question 1.
Geetha takes 15 minutes from her house to reach her school on a bicycle. If the bicycle lias a speed of 2 m/s, calculate the distance between her house and the school.
Answer:
Given : time taken = 15 minutes [1 min = 60 sec]
= 15 x 60 = 900 sec
Speed – 2 m/s
Distance = ?
Formula : Distance = Speed x time = 2 x 900
Distance between her house and the school = 1,800 m

Samacheer Kalvi 7th Science Books Question 2.
A car started from rest and travelling with velocity of 20 m /s in 10 s. What is its acceleration?
Answer:
Given :
Initial velocity of the car (u) = 0 m/s
Final velocity of the car (v) = 20 m/s
time taken = 10s
Acceleration = ?
Formula: Acceleration = \(\frac { 20 – 0 }{ 10 }\) = \(\frac { 20 }{ 10 }\)
Acceleration of the car = 2 m/s2

Samacheer Kalvi 7th Science Solution Question 3.
A bus can accelerate with an acceleration 1 m/s2. Find the minimum time for the bus to reach the speed of 100 km/s from 50 km/s.
Given :
Acceleration of the bus (a) = 1 m/s2
Initial velocity (u) = 50 km/s = 50 x 103 m/s
Final velocity (v) = 100 km/s = 100 x 103 m/s
time (t) = ?

IX. Fill in the boxes:

S.No.	First Move	Second Move	Distance (m)	Displacement
1.	Move 4 meters east	Move 2 meters west	6	2 m east
2.	Move 4 meters north	Move 2 meters south
3.	Move 2 meters east	Move 4 meters west
4.	Move 5 meters east	Move 5 meters west
5..	Move 5 meters south	Move 2 meters north
6.	Move 10 meters west	Move 3 meters east

Answer:

S.No.	First Move	Second Move	Distance (m)	Displacement
1.	Move 4 meters east	Move 2 meters west	6 m	2 m east
2.	Move 4 meters north	Move 2 meters south	6 m	2 m north
3.	Move 2 meters east	Move 4 meters west	6 m	2 m west
4.	Move 5 meters east	Move 5 meters west	10 m	0 (same place)
5..	Move 5 meters south	Move 2 meters north	7 m	3 m south
6.	Move 10 meters west	Move 3 meters east	13 m	7 m west

Samacheer Kalvi 7th Science Force and Motion Intext Activities

Activity

7th Samacheer Kalvi Science Question 1.
As shown in the above picture, Kavitha can reach her school in two ways. Can you tell, by choosing which path she could reach the school early.

Road A
Road B
Answer:
By choosing road A kavitha could reach the school early as the distance is less compared to road B.

Samacheer Kalvi 7th Science Answers Question 2.
Look at the nearby picture

In which path the leaf will reach the ground first?
Answer:
The leaf will reach the ground first by path – A, as it reaches the ground in straight line.

Question 3.
Uma and Priya are friends studying in the same school. After school hours, they go to the nearby playground, play games and return back home. One day Uma told that she would reach the playground after visiting her grandmother’s house. The path in which they took reached the playground is shown here.

Take a twine and measure the length of the two paths (A & B). Which is the longest path among the two?
Answer:
Path A is the longest among the two. as it is not a straight line.

Question 4.
The path in which a rabbit ran is shown in figure. Find the distance and displacement of it in the two figures. Let us consider that each square is in an unit of one square meter. The rabbit starts from point A and reaches the point B.

When will the distance and displacement be equal. Explain. But the starting and finishing points should be different. _______
Answer:
Distance : 17
Distance: 24
Displacement: 3
Displacement: 1
When the rabbit moves in a straight line from A to B, the distance and displacement will be equal.

Question 5.
Here we can consider the starting point as A and while the object moves from A to B the displacement is considered to be positive and from B to A it is negative.
Answer the following questions:
Subha goes to the nearby playground from her home.

Question 1.
What is the distance she travelled?
Answer:
400 m

Question 2.
What is her displacement?
Answer:
100 m

Question 3.
The distance travelled by an object is 15 km and its displacement is 15 km. What do you infer from this?
Answer:
The object moves in a straight line in one direction without turning back.

Question 4.
The distance of a person is 30 km and his displacement is 0 km. What do you infer from this?
Answer:
The distance of a person = 30 km Displacement = 0 km.

Question 5.
The person returns to the same position where he has started.
Answer:
(i.e.) The initial and the final position is same.

Question 6.
Answer the following questions:
(i) Calculate the velocity of a car travelling with a uniform velocity covering 100 m distance in 4 seconds.
Answer:

(ii) Usain Bolt covers 100 m distance in 9.58 seconds. Calculate his speed. Who will be the winner if Usain Bolt comepetes with a Cheetah running at a speed of 30 m/s

(iii) You are walking along east covering a distance of 4 m, then 2 m towards south, then 4 m towards west and at last 2 m towards north. You cover the total distance in 21 seconds, what is your average speed and average velocity?
Total distance covered = 12 m
Total time taken =21 seconds

\(\frac { 12m }{ 21 }\) = 0.571 m/s
Average velocity = 0 m/s
Average velocity is zero because the starting point and the finishing point is same
∴Displacement is zero so, average velocity is also

Question 7.
(a) Change in speed
(b) Change in direction
(c) Change in both speed and direction

The distance travelled by train	Initial velocity (u) m/s	Final velocity (v) m/s	Change in velocity (v – u) m/s	Time taken (t) s	Acceleration = change in velocity / time a = (v – u) /1 m/s2
A-B	0	6	6	10	0.6
B-C
C-D
D-E
E-F

The velocity at different times of a train departing direction is given in the figure. Analyse this and complete the table .

Answer:

The distance travelled by train	Initial velocity (u) m/s	Final velocity (v) m/s	Change in velocity (v – u) m/s	Time taken (t) s	Acceleration = change in velocity / time a = (v – u) /t m/s2
A-B	0	6	6	10	0.6
B-C	6	14	14-6 = 8	10	0.8
C-D	14	14	14-14 = 0	10	0
D-E	14	6	6- 14 =-8	10	-0.8
E-F	6	2	2 – 6 = -4	10	-0.4

Analysis:
When the train covers the distance A to B and B to C, it is accelerated motion.
When it covers the distance C-D, there is no acceleration (i.e) uniform velocity.
When it covers the distance D to E and E to F it has negative acceleration or deceleration or retardation, (i.e.) Its velocity decreases with respect to time.

Question 8.
My name is cheetah. I can run at a great speed. Do you know what my speed is? 25 m/s to 30 m/s. My speed changes from 0 to 20 m/s in 2 second. See how good my acceleration is !
From the above information, can you calculate the acceleration of the cheetah?
Answer:

Question 9.

When the velocity of the object is increasing by 20 m/s the acceleration is 20 m/s2
When the velocity of the object is decreasing by 20 m/s the deceleration is 20 m/s2.
Answer:
When the velocity of the object is decreasing by 20m/s the deceleration is 20 m/s2.

The velocity of the object is decreasing by 20m/s in one second.

Question 10.
Imagine and write a story on your own for the given graph?

Answer:
Raghul and his father starting from home to the school by car. At the school gate, he stopped the car to drop Raghul. After 2 minutes he went back to home to pick up his mother. Then they both started to go to their work. On the way, they are waiting for the signal.

Samacheer Kalvi 7th Science Force and Motion Additional Questions

I. Choose the correct answer.

Question 1.
Distance travelled by a body in a given time
(a) is always positive
(b) can be zero or positive
(c) is always negative
(d) either (a) or (c)
Answer:
(b) can be zero or positive

Question 2.
Which of the following is correct
(a) magnitude of displacement may be greater than distance.
(b) Distance is always greater than or equal to the magnitude of displacement.
(c) Distance is always greater than the magnitude of displacement.
(d) Both are scalar quantities.
Answer:
(b) Distance is always greater than or equal to the magnitude of displacement

Question 3.
Average speed of a moving object is equal to the magnitude of its average velocity when it travels.
(a) in a straight line without turning back
(b) in a circle
(c) back and forth
(d) in a zig-zag path
Answer:
(a) in a straight line without turning back

Question 4.
A car is moving along a straight road with uniform velocity which is the correct representation

Answer:

Question 5.
The slope of a velocity-time graph gives
(a) velocity
(b) distance
(c) displacement
(d) acceleration
Answer:
(d) acceleration

Question 6.
Velocity-time graph of an object is given below the object has
(a) uniform velocity
(b) uniform retardation
(c) uniform speed
(d) variable retardation
Answer:

(b) uniform retardation

Question 7.
Which one of the following graphs is showing an object is stationary?

Answer:

Question 8.
If the velocity of a body does not a changes , then its acceleration is ________
(a) Infinity
(b) unity
(c) Zero
(d) between zero and unity
Answer:
(c) Zero

II. Fill in the Blanks.

1. The SI unit of displacement is _______
2. The SI unit of speed is _______
3. _______ is the length of actual path covered by a body.
4. _______ is the distance trtavelled by a body per unit time
5. Distance is a _______quantity.
6. The displacement is zero when the initial and final positions are _______
7. Speed is always positive or zero but never be _______
8. When the velocity of a body increases with time, its acceleration is _______
9. The acceleration of a body moving with uniform velocity is _______
10. A car increases its speed from 20 km/h to 50km/h in 10 seconds. Its acceleration is _______

Answer:

1. metre (m)
2. m/s
3. Distance
4. speed
5. scalar
6. same
7. negative
8. positive
9. zero
10. 0.83 m/s2

III. Match the following :

	Column I		Column II
a.	Uniform motion.	(i)	Body having uniform acceleration
b.	Non-uniform motion.	(ii)	Body at rest.
c.	The velocity-time graph is a circle.	(iii)	Unequal distance covered in equal interval of time.
d.	Straight line parallel to time axis in position-time graph.	(iv)	Equal distances covered in equal intervals of time.
e.	Straight line inclined to 45° with time axis is velocity-time graph.	(v)	Not possible.

Answer:

1. iv
2. iii
3. v
4. i
5. ii

Very short Answers:

Question 1.
Give one example where the displacement is zero but the distance travelled is not zero.
Answer:
When an object travels is a circular path (ie. the initial and positions are same).

Question 2.
Is displacement a scalar quantity?
Answer:
No, displacement is a vector quantity as it depends on direction.

Question 3.
Give some examples for vector quantity.
Answer:
Displacement, velocity, force.

Question 4.
Give some examples for scalar quantity.
Answer:
Mass, distance, speed, temperature.

Question 5.
Give one example for uniform acceleration.
Answer:
The motion of a freely falling object.

Question 6.
Give one example for non-uniform acceleration.
Answer:
The motion of a car on a crowded road.

Question 7.
Give an example for retardation or declaration.
Answer:
When a person applies brake on a moving car, its velocity decreases with time.

Question 8.
What are three types of stability of an object?
Answer:

1. Stable equilibrium
2. Unstable equilibrium
3. Neutral equilibrium

Question 9.
Mention any two conditions for stability of a body?
Answer:

1. Increase the area of its base.
2. Lower its centre of gravity.

V. Give Short Answer.

Question 1.
A body moves is a circle of radius ‘2R’ what is the distance covered and displacement of the body after 2 complete rounds?
Answer:
Distance covered after 2 complete rounds
= 2 x circumference of a circle
Distance =2 × 2 π(2R) = 4π(2R)

After 2 complete rounds, the body comes back to its initial position,
so, displacement = 0

Question 2.
What are the uses of graphical study of motion?
Answer:

1. By simply looking at the graph, one can tell whether motion is uniform or not.
2. It is useful for comparing the motions of two moving bodies.

Question 3.
Draw distance-time graphs for the following

1. a stationary body
2. a body moving with variable velocity

Answer:

Question 4.
Draw centre of gravity of the following regular shaped objects.

Answer:

Question 5.
Mention the real life applications of centre of gravity.
Answer:

1. Luggage compartment of a tour bus is located at the bottom and not on the roof.
2. Racing cars are built low and broad for stability.
3. Table lamps and fans are designed with large heavy bases to make them stable

Question 6.
Explain the concept which is used in the continuous movement of Thanjavur doll?
Answer:
The centre of gravity and the total weight of the doll is concentrated at its bottom most point, generating a dance-like continuous movement with slow oscillations.

Question 7.
Write note on the following :

1. Nautical mile
2. knot.

Answer:

1. Nautical mile is the unit for measuring the distance in the field of aviation and sea transportation. One nautical mile is 1.852 km.
2. The unit for measuring the speed of aeroplanes and ships is knot. One knot is the speed taken to travel one nautical mile in hour.

Question 8.
Saranya jogs from one end A to the other end B of a straight road of length 320m in 2min 40 seconds. Then she turns back and jogs 100m to point C in 1 min. what is her average velocity in jogging.
Answer:
Total displacement = 320m
From A to C displacement = 320 -100 = 220m
Time taken = 3 min 40 sec
= 180+40=220

Question 9.
A train starting from a railway station and moving with uniform acceleration attains a speed of 40 km/h in 10 minutes. Find its acceleration?
Answer:
Initial velocity (u) = Okm/h
Final velocity (v) = 40 km/h
Time (t) = 10 min = \(\frac { 10 }{ 60h }\) = \(\frac { 1 }{ 6h }\)
Acceleration (a) = \(\frac { v – u }{ t }\)
\(\frac { 40 – 0 }{ 1 }\) = 40 × 6
= 240 km/h

Question 10.
Define speed Mention its formula and unit.
Answer:
Speed is the rate of change of distance .
Formula : Speed = distance /time
Unit is meter/second (m/s)

Question 11.
Define velocity Mention its formula and unit.
Answer:
Velocity is the rate of change in displacement.
Formula : Velocity (v) = displacement / time
SI unit of velocity is meter / second (m/s).

Question 12.
What is uniform velocity? Give one example.
Answer:
A body has uniform velocity, if it covers equal displacement in the same direction in equal intervals of time. Eg. light travels through vacuum.

Question 13.
What is non-uniform velocity? Give example.
Answer:
If either speed or direction changes, then the velocity is non uniform. Eg. a train starting and moving out of the station.

Question 14.
Define acceleration. Mention its formula and unit.
Answer:
Acceleration is the rate of change in velocity.
Formula : Acceleration = change in velocity / time SI unit of acceleration is m/s2

Question 15.
Define the following:

1. positive acceleration
2. negative acceleration.

Answer:

(i) Positive acceleration:
If the velocity of an object increases with respect to time, then the object is said to be in positive acceleration or just acceleration.

(ii) Negative acceleration or deceleration or retardation:
If the velocity of an object decreases with respect to time, then the object is said to be in negative acceleration or deceleration or retardation.

VI. Long Answer
Question 1.
Write the differences between distance and displacement
Answer:

	Distance	Displacement
1.	The total length of a path taken by an object to reach one place from the other is called distance.	The shortest distance from the initial to the final position of an object.
2.	Distance between two gives points may be same or different paths chosen.	Displacement between two given points is always same
3.	It is a scalar quantity	It is a vector quantity
4.	Distance covered is always positive or zero.	Displacement covered may be positive, negative or zero

Question 2.
Draw velocity-time graph for the following data:

Answer:

Question 3.
Bus travelling at uniform speed of m/s

Answer:

Question 4.
Bus travelling at uniform acceleration

Answer:

Question 5.
Bus travelling at uniform deceleration

Answer:

Question 6.
Bus travelling with increasing acceleration (non – uniform acceleration)

Answer:

Students can Download Tamil Chapter 3.3 பேசும் ஓவியங்கள் Questions and Answers, Summary, Notes Pdf, Samacheer Kalvi 7th Tamil Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 7th Tamil Solutions Term 2 Chapter 3.3 பேசும் ஓவியங்கள்

மதிப்பீடு

சரியான விடையைத் தேர்ந்தெடுத்து எழுதுக.

Question 1.
குகை ஓவியங்களில் வண்ண ம் தீட்டப் பயன்பட்ட பொருள்களில் ஒன்று ………….
அ) மண்துகள்
ஆ) நீர் வண்ணம்
இ) எண்ணெய் வண்ணம்
ஈ) கரிக்கோல்
Answer:
அ) மண்துகள்

Question 2.
நகைச்சுவை உணர்வு வெளிப்படுமாறு வரையப்படும் ஓவியம் …
அ) குகை ஓவியம்
ஆ) சுவர் ஓவியம்
இ) கண்ணாடி ஓவியம்
ஈ) கேலிச்சித்திரம்
Answer:
ஈ) கேலிச்சித்திரம்

Question 3.
‘கோட்டோவியம்’ என்னும் சொல்லைப் பிரித்து எழுதக் கிடைப்பது ………………..
அ) கோடு + ஓவியம்
ஆ) கோட்டு + ஓவியம்
இ) கோட் + டோவியம்
ஈ) கோடி + ஓவியம்
Answer:
அ) கோடு + ஓவியம்

Question 4.
‘செப்பேடு’ என்னும் சொல்லைப் பிரித்து எழுதக் கிடைப்பது …………
அ) செப்பு + ஈடு
ஆ) செப்பு + ஓடு
இ) செப்பு + ஏடு
ஈ) செப்பு + யேடு
Answer:
இ) செப்பு + ஏடு

Question 5.
எழுத்து + ஆணி என்பதனைச் சேர்த்தெழுதக் கிடைக்கும் சொல் ………………
அ) எழுத்து ஆணி
ஆ) எழுத்தாணி
இ) எழுத்துதாணி
ஈ) எழுதாணி
Answer:
ஆ) எழுத்தாணி

கோடிட்ட இடங்களை நிரப்புக

Question 1.
கருத்துப் படங்களை அறிமுகப்படுத்தியவர் ……………..
Answer:
பாரதியார்

Question 2.
கலம்காரி ஓவியம் என்று அழைக்கப்படுவது ……………………
Answer:
துணி ஓவியம்

Question 3.
மன்னர்களின் ஆணைகளையும் அரசு ஆவணங்களையும் ……………… மீது பொறித்துப் பாதுகாத்தனர்.
Answer:
செப்பேடுகளின்

குறுவினா

Question 1.
ஓவியங்களின் வகைகள் யாவை?
Answer:
ஓவியங்களின் வகைகள் : குகை ஓவியம், சுவர் ஓவியம், துணி ஓவியம், ஓலைச்சுவடி ஓவியம், செப்பேட்டு ஓவியம், தந்த ஓவியம், கண்ணாடி ஓவியம், தாள் ஓவியம், கருத்துப்படம் ஓவியம், நவீன ஓவியம்.

Question 2.
குகை ஓவியங்களில் இருந்து நாம் அறியும் செய்திகள் யாவை?
Answer:
பழங்கால மனிதர்கள் குகைகளில் வாழ்ந்தனர். அவர்கள் செய்திகளைப் பிறருக்குத் தெரிவிக்கவே குகை ஓவியங்களை வரையத் தொடங்கினர்.

Question 3.
தாள் ஒவியங்களை எவற்றைக் கொண்டு வரைவர்?
Answer:
கரிக்கோல், நீர்வண்ணம், எண்ணெய் வண்ணம் முதலியனவற்றைக் கொண்டு தாள் ஓவியங்கள் வரையப்படுகின்றன.

Question 4.
சுவர் ஓவியங்கள் காணப்படும் இடங்களைக் கூறுக.
Answer:
அரண்மனைகள், மண்டபங்கள், கோயில்கள் போன்றவற்றின் சுவர்களிலும் மேற்கூரைகளிலும் சுவர் ஓவியங்களைக் காணலாம்.

Question 5.
செப்பேட்டு ஓவியங்களில் காணப்படும் காட்சிகள் யாவை?
Answer:

• நீர்நிலைகள்
• செடி கொடிகள்
• பறவைகள்
• விலங்குகள்
• குறியீடுகள்

சிறுவினா

Question 1.
கேலி சித்திரம் என்றால் என்ன?
Answer:

• அரசியல் கருத்துகளை எளிமையான படங்களைக் கொண்டு விளக்க உருவாக்கப்பட்டதே கருத்துப்பட ஓவியம் ஆகும்.
• கருத்துப்பட ஓவியங்களின் மற்றொரு வடிவமே கேலிச்சித்திரம் எனப்படும்.
• தமிழ்நாட்டில் முதன் முதலாக கருத்துப்படங்களை வெளியிட்டவர் பாரதியார். ஆங்கிலேயர் ஆட்சியின் குறைகளை இந்தியா என்னும் இதழில் கேலிச்சித்திரங்களின் மூலம் வெளியிட்டார். இப்பொழுது பெரும்பாலான இதழ்களில் இவை இடம் பெறுகின்றன.
• மனித உருவங்களை விந்தையான தோற்றங்களில் நகைச்சுவை உணர்வு
  தோன்றும்படி வரைவதே கேலிச்சித்திரம் ஆகும்.

Question 2.
ஓலைச்சுவடி ஓவியங்கள் குறித்து நீங்கள் அறிந்து கொண்டவற்றை எழுதுக.
Answer:

• ஓலைச்சுவடிகள் மீது எழுத்தாணிகளைக் கொண்டு கோட்டோவியமாகவும், வண்ணப் பூச்சு ஓவியமாகவும் ஓலைச்சுவடி ஓவியங்கள் வரையப்பட்டன.
• இதிகாசம் மற்றும் புராணக் காட்சிகளாகவே இத்தகைய ஓவியங்கள் இடம் பெற்றிருக்கும்.
• தஞ்சாவூர் சரசுவதி மகால் நூலகத்தில் ஓலைச்சுவடி ஓவியங்கள் பாதுகாத்து வைக்கப்பட்டுள்ளன.
• தற்காலத்தில் ஓலைச்சுவடி ஓவியங்களைக் காண்பது அரிது.

சிந்தனை வினா

Question 1.
தந்த ஓவியங்கள் கேரளாவில் அதிகம் காணப்படுவது ஏன்?
Answer:
கேரளா இயற்கையன்னையின் உறைவிடமாக உள்ளது. தொடர்ச்சியான மலைகள், அழகான நீர்நிலைகள் எனக் கொஞ்சும் இயற்கை அமைப்பு. இதனால் இம்மாநிலத்தில் வனவிலங்குகள் பெருகியுள்ளன. யானைகளும் அதிகமாக இரு வனத்துறையினரால் யானைகள் பாதுகாக்கப்படுகின்றன. யானைகள் வாழ்வ சூழல் இருப்பதால் அதிக அளவில் யானைகள் இங்கு இருக்கின்றன. அதனால் தந்தத்தால் ஆன ஓவியங்கள் அதிகம் காணப்படுகின்றன.

கற்பவை கற்றபின்

Question 1.
உமக்குப் பிடித்த காட்சியை வரைந்து வண்ணம் தீட்டுக.
Answer:
மாணவர்கள் தாங்களாகவே செய்ய வேண்டியவை.

Question 2.
பருவ இதழ்களில் வெளிவந்த பலவகை ஓவியங்களைச் சேகரித்துப் படத்தொகுப்பு உருவாக்குக.
Answer:
மாணவர்கள் தாங்களாகவே செய்ய வேண்டியவை.

கூடுதல் வினாக்கள்

நீரப்புக.

Question 1.
…………. சுவர் ஓவியங்களை ஏராளமாகக் காண முடியும்.
Answer:
தஞ்சைப் பெரிய கோயிலில்

Question 2.
சீவகசிந்தாமணிக் காப்பியத்தில் ………………… என்னும் தலைவி யானையைக் கண்டு அஞ்சிய காட்சியைச் சீவகன் துணியில் வரைந்ததாகக் கூறப்பட்டுள்ளது.
Answer:
குணமாலை

Question 3.
ஐரோப்பியக் கலை நுணுக்கத்துடன் இந்தியக் கதை மரபுகளை இணைத்து ஓவியங்களில் புதுமைகளைப் புகுத்தியவர் ………………….
Answer:
இராஜா இரவிவர்மா

Question 4.
நாட்காட்டி ஓவியம் வரையும் முறையின் முன்னோடிகளுள் ஒருவராகக் கருதப்படுபவர்
Answer:
கொண்டையராஜு

Question 5.
நாட்காட்டி ஓவியங்களைப் …………….. என்றும் அழைப்பர்.
Answer:
பசார் பெயிண்டிங்

விடையளி :

Question 1.
ஓவியம் வரைபவரின் வேறு பெயர்களை எழுதுக.
Answer:
கண்ணுள் வினைஞர், ஓவியப் புலவர், ஓவமாக்கள், கிளவி வல்லோன், சித்திரக்காரர், வித்தகர்.

Question 2.
ஓவியம் வேறு பெயர்கள் யாவை?
Answer:
ஓவு, ஓவியம், ஓவம், சித்திரம், படம், படாம், வட்டிகைச்செய்தி.

Question 3.
ஓவியக் கூடம் வேறு பெயர்கள் யாவை?
Answer:
எழுதெழில் அம்பலம், எழுத்துநிலை மண்டபம், சித்திர அம்பலம், சித்திரக்கூடம், சித்திரமாடம், சித்திர மண்டபம், சித்திர சபை.

Question 4.
தந்த ஓவியம் பற்றி எழுதுக.
Answer:
வயது முதிர்ந்து இறந்த யானையின் தந்தங்களின் மீது பலவகை நீர் வண்ணங்களைப் பயன்படுத்தி அழகான ஓவியங்களாக வரைவார்கள். தந்த ஓவியர்களைக் கேரள மாநிலத்தில் அதிகமாகக் காணமுடியும்.

Question 5.
கண்ணாடி ஓவியம் பற்றி எழுதுக.
Answer:
அழகிய வண்ண ஓவியங்கள் வரைய கண்ணாடிகளைப் பயன்படுத்துகின்றனர். கண்ணாடி ஓவியங்களை உருவாக்கும் ஓவியர்கள் தஞ்சாவூரில் மிகுதியாக உள்ளனர்.

Students can Download Science Chapter 1 Light Questions and Answers, Notes Pdf, Samacheer Kalvi 7th Science Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 7th Science Solutions Term 3 Chapter 1 Light

Samacheer Kalvi 7th Science Light Textual Evaluation

I. Choose the correct option:

Light That Hits A Mirror Gets Question 1.
Light travels only in a ______ .It is because of this property that.
(a) curved line, shadows
(b) straight line, shadows
(c) straight line, reflection
(d) curved line and then straight line, shadows
Answer:
(b) straight line, shadows

Light That Hits A Mirror Gets Answer Question 2.
Light that hits a mirror gets ______
(a) Transmitted
(b) Reflected
(c) Absorbed
(d) Refracted
Answer:
(b) Reflected

Samacheer Kalvi Guru 7th Science Question 3.
______ surface reflects the light well
(a) Water
(b) Compact disc
(c) Mirror
(d) Stone
Answer:
(c) Mirror

Samacheer Kalvi 7th Science Guide Question 4.
Light is a form of ____
(a) matter
(b) energy
(c) medium
(d) partical
Answer:
(b) energy

Light Samacheer Kalvi Question 5.
You can see your image in polished floors, but not in wooden table because ______
(a) regular reflection takes place in wooden table and irregular reflection in polished floor
(b) regular reflection takes place in polished floor and irregular reflection in wooden table
(c) regular reflection takes place in both polished floor and wooden table
(d) irregular reflection takes place in both polished floor and wooden table
Answer:
(b) regular reflection takes place in polished floor and irregular reflection in wooden table

Samacheer Kalvi 7th Science Books Answers Question 6.
Choose the translucent substance from the following
(a) glass
(b) wood
(c) water
(d) Clouds
Answer:
(d) clouds

Samacheer Kalvi 7th Science Question 7.
Reflection occurs , when the light
(a) about to reach a surface
(b) approaches a surface
(c) passes through a surface
(d) None Of these
Answer:
(b) approaches a surface

7th Science Term 3 Question 8.
Which of the following is the best reflector
(a) plastic plate
(b) plane mirror
(c) wall
(d) paper
Answer:
(b) plane mirror

Samacheer Kalvi 7th Science Answers Question 9.
Sivarajan placed a meter stick in the playground at 7.00 am in the morning. How will the shadow of the stick at noon look in comparison to the one in the morning
(a) There will be no shadow
(b) The shadow will be longer and on the opposite side as the sun
(c) The shadow will be shorter and on the same side as the sun
(d) The shadow will be shorter
Answer:
(d) The shadow will be shorter

Samacheer Kalvi 7th Science Book Back Answers Question 10.
The image formed by a pinhole camera is inverted because,
(a) light travels in straight lines
(b) light rays become laterally inverted as they pass through a pinhole camera
(c) light rays pass through the pinhole
(d) light rays get reflected
Answer:
(a) light travels in straight lines

7th Science Samacheer Kalvi Question 11.
Which of the following facts explain how shadows are formed?
(a) Light travels in straight lines
(b) Opaque bodies do not allow light to pass through them
(c) Reflection occurs at a smooth surfaces like mirrors
(d) Lateral inversion happens
(a) both A and B
(b) both A and D
(c) both B and C
(d) only A
Answer:
(a) both A and B

II. Fill in the blanks:

1. A plane mirror produces a _________ image
2. A _________ reflection helps us to see the objects.
3. The light ray gets _________ when it falls on any polisher surface
4. Sunlight is a blend of _________ colours
5. The splitting of white light into seven colours is called _________
6. The moon _________ sun light.
7. The sunlight can be split into its constituent colours using _________
8. Reflection of light from rough surface is called _________ reflection

Answer:

1. virtual and erect
2. regular
3. reflected
4. seven
5. dispersion
6. reflects
7. prism
8. irregular

III. Say TRUE or FALSE.

Samacheer Kalvi 7th Science Book Question 1.
The image of right hand in a plane mirror looks like a left hand.
Answer:
True

7th Standard Term 3 Science Question 2.
Rainbow is formed by dispersion of which light by water drops.
Answer:
True

Light Chapter Of Class 7 Pdf Question 3.
The image formed by the plane mirror is laterally inverted, hence the image seen through the periscope is also laterally inverted
Answer:
False
Correct statement: The image formed by the plane mirror is laterally inverted, hence the image seen through the periscope is This is because in periscope, image is reflected by two mirrors.

Question 4.
We see planets because they reflect light from the sun
Answer:
True

Question 5.
We see a book because it reflects the light that falls on its surface
Answer:
True

Question 6.
The image formed in a pinhole camera is always inverted
Answer:
True

Question 7.
The image formed in a pinhole camera is always the satne size as the object
Answer:
False

Question 8.
The image formed in a plane mirror is upside down
Answer:
False
Correct statement: The image formed in a plane mirror is erect.

Question 9.
A plane mirror is opaque Ans.
Answer:
True

Question 10.
A shadow is formed on the same side of the object as the source of light.
Answer:
False
Correct statement: A shadow is formed on the side of the object as the source of light.

Question 11.
We are able to see things around us with the help of regular reflection
Answer:
True

Question 12.
After passing through a prism, white light splits into a band of seven colours
Answer:
True

IV. Match the following

1.	Rectilinear propagation	Primary source of light
2.	Rectilinear propagation	Non-luminous object
3.	Plane Mirror Fire fly	Periscope
4.	The Moon	Pinhole camera
5.	Wide light source	Spectrum of light
6.	Regular reflection	luminous object
7.	The sun	Penumbra
8.	Band of seven colors	Glossy surface

Answer:

1.	Rectilinear propagation	Pinhole camera
2.	Rectilinear propagation	Periscope
3.	Plane Mirror Fire fly	luminous object
4.	The Moon	Non-luminous object
5.	Wide light source	Penumbra
6.	Regular reflection	Glossy surface
7.	The sun	Primary source of light
8.	Band of seven colors	Spectrum of light

V. Answer the following questions in short:

Question 1.
With the help of a diagram, state the laws of reflection
Answer:
Laws of reflection:

1. The angle of incidence is always equal to the angle of reflection li =l*
2. The incident ray, the reflected ray and the normal at the point of incidence lie on the same plane.

Question 2.
Figure shows a pencil placed above a mirror

a) Draw its image formed by the mirror
b) Show how light rays from the object are reflected at the mirror to form the image for the eye.
Answer:

Question 3.
A person is looking at the image of a tree in a mirror placed 3.5 m in front of him. Given that the tree is at 0.5 m behind his eyes. Find the distance between the image of the tree and his eyes. What are needed to see an object?
Answer:

Distance between the person and the mirror = 3.5 m
Distance between the person and tree (object) = 0.5 m
The image formed in the mirror = 4 m
The distance between the image of the tree and his eyes = 4 + 3.5 = 7.5

Question 4.
What are luminous objects?
Answer:
All objects which emit light energy by themselves are called luminous objects. Ex.: Sun, electric bulb.

Question 5.
Is thr moon a luminous object?
Answer:
No, the moon is non-luminous. The reason is that moon does not produce its own light. Instead, it reflects the light of the sun falling on it.

Question 6.
What are the three types of materials based on the absorption of light?
Answer:

1. Transparent Material
2. Translucent Material
3. Opaque Material

Question 7.
What are the parts of shadow?
Answer:

1. Umbra
2. Penumbra

Question 8.
What are the properties of shadow?
Answer:
Properties of shadow:

1. All objects do not form shadows. Only opaque objects form shadows.
2. Shadows will be formed in the opposite side of light source.
3. It cannot be determined the characteristics of an object by its shadow.
4. The shadow will be always darker, whatever may be the color of light rays.
5. Light source, opaque object are shadow all are in a straight line.
6. The size of shadow depends upon the distance between light source and object and the distance between object and the screen.

Question 9.
What is plane mirror?
Answer:
A plane mirror is a mirror with a flat reflective surface. A plane mirror makes an image of objects in front of it.

Question 10.
What is prism?
Answer:
A prism is an object made up of a transparent material, like glass or plastic that has at least two flat surfaces that form an acute angle (less than 90°).

Question 11.
What do you mean by visible light?
Answer:
Visible light is a spectrum of a number of waves with different wavelength range from 400nm to 700nm (lnm = 10″9 meter) each wave has a definite wavelength represents a particular colour.

Question 12.
Write the items given here in the correct column (Stars, brick walls, plants, mirror, planets, electric light bulb, candle)

Sources of Light	Objects that reflect light

Answer:

Sources of Light	Objects that reflect light
Stars	Brick walls
Electric light bulb	Plants
Candle	Mirror
	Planets

Question 13.
A boy of height lm 45 cm is standing in front of a long mirror at a distance of 2 m. From this information, fill up the following sentences:
a) The distance between the boy and his image is ______
b) The height of the image is ______
c) When the boy moves 1 m forward, the distance between her and her image is ______
Answer:
(a) The distance between the boy and his image is 4m
(b) The height of the image is same.
(c) When the boy moves 1 m forward, the distance between her and her image is 2m.

Question 14.
Draw a diagram of a pinhole camera showing the rays of light passing between the Object and its image
Answer:

Question 15.
Why is the writing on the front of an ambulance back to front as shown in the picture

Answer:

1. This is due to lateral inversion.
2. The phenomenon due to which the left side of an object appears to be right side of the object in its image in a reflecting medium (mirror).
3. So that drivers see the word the right way around in their rear-view mirror.

Question 16.
Explain with examples, why some capital letters look the same in a mirror but others are reversed.
Answer:
Any letter that has a bilateral symmetry will have its mirror image the same as that of the object.
Example:

Question 17.
Two plane mirrors M1 and M2 are placed perpendicular with each other, as shown in figure. The ray AB makes an angle 39° with the plane mirror M , then

1. The reflected rays are _________, ____________
2. The incident rays are _________, ____________
3. What is the angle of incident corresponding to the ray BC?
4. What is the angle of reflection corresponding to the ray CD

Answer:

1. BC, CD
2. AB, BC
3. \(\lfloor i\) = 39°
4. \(\lfloor r\) = 39°

Question 18.
Raj an was playing with the mirror images of a clock. He looked at the clock in his roomIt was showing 1:40. Draw the position of the hands on the real clock and on its mirror reflection .Write below the picture what time each picture

Answer:

Question 19.
What is reflection of light?
Answer:
The bouncing back of light from a reflecting surface of an object is called as reflection of light

Question 20.
If a ray of light is falling on a plane mirror at an angle of 50° is formed, what will be the angle of reflection?
Answer:

Angle of incidence \(\lfloor i\) = 90° – 50°
\(\lfloor i\) = 40°
According to laws of reflection,
\(\lfloor i\) = \(\lfloor k\)
Angle of incidence = Angle of reflection
\(\lfloor i\) = 40°
∴ \(\lfloor r\) – 40°
Angle of reflection \(\lfloor r\) = 40°

Question 21.
What do you mean by lateral inversion?
Answer:
The phenomenon due to which left hand side of object appears as right hand side and vice versa is called lateral inversion.

Question 22.
How do you obtain a spectrum of light?
Answer:
When white light is made to fall on the surface of a prism, it disperses and we obtain a spectrum of light.

Question 23.
Why do we see white color in Newton’s disc, when we rotate it very fast?
Answer:
When the disc turned quickly, the retina receives the sensation of the spectrum simultaneously and disc appears white.

Question 24
What is a shadow? What things are necessary for the formation of a shadow?
Answer:

1. Shadows are formed because light travels in straight lines.
2. Shadow is always against, opposite side of light source.
3. Shadow is formed by opaque objects that stop high from propagating.
4. Things necessary for the formation of shadow: source of light,opaque object

VI. Answer the following questions in detail:

Question 1.
What are regular and irregular reflection? Explain with the help of diagrams
Answer:
(i) Regular reflection When a parallel beam of light on striking some smooth and polished surface is reflected as a parallel beam of light, such a reflection is called regular reflection.

(ii) Irregular reflection : When a parallel beam of light, on striking some rough surface, is reflected in different directions, then such a reflection is called irregular or diffused reflection.

Question 2.
What are the difference between luminous and non-luminous objects? Give two examples of each.
Answer:

	Luminous objects	Non-luminous objects
1.	All objects which emit light energy by themselves are called luminous objects.	All objects which do not emit light energy of their own, but reflect the light energy falling on them and hence, become visible are called non- luminous object.
2.	Ex.: Sun, stars, torch light, burning candle etc.	Ex.: Metals, trees, houses, stones, moon etc.

Question 3.
Write about two everyday situations that tell you that light travels in a straight line.
Answer:

1. Formation of shadow: Shadows are formed when some light rays continue its travel in straight lines while other rays are stopped by an object.
2. When there is a small hole in a room, light travels only in a straight line.

Question 4.
Differentiate between a reflection and a shadow
Answer:

Reflection	Shadow
When light falls on a surface, the direction of ray is changed. This change in direction is known as reflection of light.	Shadow is an image formed by obstruction of light.
Eg.: You see your reflection in a pool of water or mirror.	Eg.: If you place your hand in front of a candle, you will see the image of the hand on the wall. This image will show only the outline of the object placed in front of the light source.

Question 5.
What are the characteristics of an image formed in a plane mirror?
Answer:

1. Image formed in a plane mirror is upright.
2. Image formed in a plane mirror is virtual The image is of the same size as the object
3. The distance of the image from the plane mirror is equal to the distance of the object from the mirror.
4. Image is laterally inverted.

Question 6.
Describe the picture

Answer:

1. When the tube is bent, we cannot see the source of light
2. When the tube is held straight we can see the flame. The two pictures verify that light travels in straight lines. This is known as rectilinear propagation of light.

Question 7.
Define the following terms
a. Incident ray
b. Reflected ray
c. Normal
d. Angle of incidence
Answer:
(a) Incident tavi The ray of light that falls on the surface of the reflection materials.
(b) Reflected ray: The ray of light that comes from the point when the incident ray falls on the reflection material.
(c) Normal: The perpendicular line drawn from, the point of incidence to the plane of reflecting surface is called normal.
(d) Angl e of incidence The angle formed between the incident ray PO and the normal ‘ON’ is angle of incidence.

Question 8.
Compare the images formed by plane mirror with that by pinhole camera
Answer:
Difference between the images formed in Pinhole camera and Plane mirror:

Image formed by Pin hole camera	Images formed in Plane mirror
The image is real.	The image is virtual
The image may not be equal to the size of the object	The image is equal to the size of the object
The image is inverted	The image is erect

Samacheer Kalvi 7th Science Light Intext Activities

Activity – 4

Let’s categorize transparent material, translucent material and opaque material among f the given materials
(Clear plastic ruler, cellophane paper, some water in a glass jar, tissue paper, drinking glass, beaker, tap water, kerosene, coconut oil, note paper, card board, milk, diluted milk, aluminum foil, thick colored plastic lid, rough glass piece, measuring glass with water, wooden piece) Place all the materials given above in the dark room. Focus a torch light on one side of each material. Inspect the light coming out at the other side of each material and then classify the materials in the table.

S.No	Transparent Material	Translucent Material	Opaque Material
1.	Clear plastic ruler	Kerosene	Card board
2.	Drinking glass	Milk	Wooden piece
3.	Beaker	diluted milk	aluminium foil
4.	Tap water	rough glass piece	thick coloured plastic lid.
5.	Measuring glass with water	tissue paper
6.	Cell phone paper	Note paper

Activity – 6

Surfaces	Property of Image (Clearer / blurred)
Glass	Blurred
Metal Sheet	Blurred
Aluminum foil	Clearer
Whitepaper	Clearer

Activity – 7

There are eight letters in the word EINSTEIN

1. Write the word in front of a plane mirror shown in diagram
2. Write down how these letters appear in the mirror
3. How many of these letters appear to be different, when the word is reflected?
4. Write down the letters that appear to be the same.

Answer:
(i)

(ii)

(iii) 3 letters (E,N,S)
(iv) I,T

Activity – 10
You need Gelatin papers of Red, Blue and Yellow. Fold each gelatin paper three times and look different colour objects listed below through each folded paper. Observe what colour each object has. Write your observations in the table.

Object	Original colour of object	Colour through Red gelatin paper	Colour through Blue gelatin paper	Colour through Yellow gelatin paper
Blue sky	Blue
Orange flower	Orange
Yellow banana	Yellow
leaves	Green
Brown trouser	Brown
White shirt	White	Red	Blue	Yellow
Black board	Black

Samacheer Kalvi 7th Science Light Additional Questions

I. Choose the correct answer.

Question 1.
Which of the following is a natural source of light?
(a) Electric lamp
(b) Electric filament
(c) Torch light
(d) Sunlight
Answer:
(d) Sunlight

Question 2.
Light shows ________
(a) curvilinear propagation
(b) random propagation
(c) rectilinear propagation
(d) none of these
Answer
(c) rectilinear propagation

Question 3.
Rectilinear propagation is ________
(a) mode of travelling in straight lines
(b) mode of travelling in curved lines
(c) ability to bend around obstacles
(d) displaying the phenomenon of diffraction
Answer
(a) made of travelling in straight lines

Question 4.
Plane mirrors are arranged parallel to each other to get ________
(a) a single image
(b) two images
(c) a large number of reflected image
(d) no image
Answer:
(d) two images

Question 5.
Which of the following is not luminous object?
(a) Sun
(b) Moon
(c) Candle
(d) Bulb
Answer
(b) Moon

Question 6.
White light is composed of ________
(a) seven colours
(b) five colours
(c) three colours
(d) only one colours
Answer:
(a) seven colours

Question 7.
The image which can be obtained on screen is called ________
(a) erect
(b) real
(c) virtual
(d) inverted
Answer:
(b) real

Question 8.
If we mix lights of the colours of the rainbow we will get .
(a) pink light
(b) brown light
(c) colourless light
(d) black light
Answer:
(c) colourless light

Question 9.
Which one of the following is involved for the formation of rainbow in the sky?
(a) Expansion of light
(b) Expansion of heat by the Sun
(c) Distance between the Earth and the Moon
(d) Dispersion of light
Answer:
(d) Dispersion of light

Question 10.
A virtual image is
(a) always real
(b) always uncapturable on a screen
(c) always inverted
(d) always caught on a screen
Answer:
(b) always uncapturable on a screen

II. Fill in the Blanks.

1. Objects which are able to emit light are known as ______
2. Passing electricity through certain gases at a very low pressure can produce ______
3. ______ is a simple device which helps us to understand about the rectilinear propagation of light.
4. The light falling on the mirror is called ______ as and the light reflected is called
5. The angle formed between the reflected ray and the normal is ______
6. Light travels ______ km per second in air or vacuum.
7. Materials that allow light to pass through completely are known as ______ material.
8. Materials that allow light to pass through partially are called ______ materials.
9. Materials that are not able to allow light to pass through it are called ______ materials.
10. ______ is always against, opposite side of light source.
11. The ______ is the darkest part of a shadow.
12. The lighter shade of shadow is the ______
13. Only ______ objects forms shadows.
14. ______ eclipse occurs, when the moon arrives between the sun and the Earth.
15. ______ cables are able to carry more signals than traditional copper cable telephone lines.
16. The images that are obtained on a screen are called ______ and that which cannot be obtained on a screen is ______
17. When all colours of visible light strikes the retina of our eye at the same time, our brain perceives ______
18. ______ colour is scattered the least by air molecules.
19. ______ is the method of creating colour by mixing various proportion of two or three distinct colours of light.
20. ______ Magenta, Cyan and yellow are called colours.

Answer:

1. light sources
2. Light
3. Pin-hole camera
4. incident ray, reflected ray
5. angle of reflection
6. 3 lakh
7. transparent
8. translucent
9. opaque
10. Shadow
11. umbra
12. penumbra
13. opaque
14. Solar
15. Fibre optic
16. real image, virtual image
17. white
18. Red
19. Synthesis
20. secondary

III. True or False – If false give the correct statement.

Question 1.
Angle of incidence is greater than the angle of reflection.
Answer:
False
Correct statement: Angle of incidence is o the angle of reflection.

Question 2.
The image formed by a plane mirror is real.
Answer:
False.
Correct statement: The image formed by a plane mirror is virt ual and erect.

Question 3.
Diffused reflection gives a sharp image.
Answer:
False.
Correct statement: reflection gives a sharp image.

Question 4.
The image formed by a plane mirror is always that far behind the mirror as far the object lies in front of it.
True.
You can see a rainbow only when your back is towards the sun.
True.

Question 5.
You can see a rainbow only when your back is towards the sun.
Answer:
True.

Question 6.
The image of symmetrical letters like A, H, I, M, R, K, T, U are not affected by lateral inversion.
Answer:
Correct statement: The image of symmetrical letters like A, H, I, M, T, U are not affected by lateral inversion.

Question 7.
Plane mirrors are used as looking glass, to reflect light on objects and in periscopes.
Answer:
True

Question 8.
We can not get white light when we mix seven colours.
False
Correct statement: We can get white light when we mix seven colours.

Question 9.
Materials that allow light to pass through completely are known as transparent material
Answer:
True

Question 10.
Solar and lunar eclipses are occuring due to the property of light known as the rectilinear propagation of light.
Answer:
True

IV. Match the following :

Question 1.

1.	Rubber	(a)	Erect
2.	Greased paper	(b)	Inverted
3,	Real image	(c)	Opaque medium
4.	Virtual image	(d)	Translucent medium

Answer:

1. c
2. d
3. b
4. a

Question 2.

1.	Real image	(a)	Diffuse reflection
2.	Virtual image	(b)	An optical device which produces reflection
3.	Mirror	(c)	Cannot be taken on screen
4.	A type of light scattering	(d)	Can be taken on screen

Answer:

1. d
2. c
3. b
4. a

V. Assertion and Reason.

Mark the correct choice as
(a) Both A and R are true and R is the correct explanation of assertion.
(b) Both A and R are true but R is not the correct explanation of assertion.
(c) A is true but R is false.
(d) A is false but R is true.

Question 1.
Assertion (A) : A plane mirror produces virtual, erect image for any position of the object.
Reason (R) : Lateral inversion is an important property of image formed by a plane mirror.
Answer:
(b) Both A and R are true but R is not the correct explanation of assertion.
Correct reason: It is because of the property of image formed in a plane mirror.

Question 2.
Assertion (A) : When an object is placed between two plane mirrors; then all the images
found are of unequal intensity.
Reason (R) : In case of plane parallel mirrors, only two images are possible.
Answer:
(c) A is true but R is false
Correct reason: In case of plane parallel mirrors, infinite images are formed.

Question 3.
Assertion (A) : Virtual object can’t be seen by human eye.
Reason (R) : Virtual image is formed by converging rays.
Answer:
(c) A is true but R is false
Correct reason: Virtual image is formed by diverging rays.

Question 4.
Assertion (A) : A ray incident along normal to the mirror retraces its path.
Reason (R) : In reflection, angle of incidence is always equal to angle of reflection.
Answer:
(a) Both A and R are true and R is the correct explanation of assertion

VI. Very short Answers:

Question 1.
What is the composition of sunlight?
Answer:
Sunlight is a mixture of seven colours.

Question 2.
How does light travel?
Answer:
Light travels along a straight line.

Question 3.
What kind of surface reflects light?
Answer:
Smooth and shiny surface reflects light.

Question 4.
Name the triangular piece of glass that splits white light into different colours.
Answer:
Prism.

Question 5.
What is reflection of light?
Answer:
When light falls on smooth surface like mirror then it changes its direction, it is called reflection.

Question 6.
State the size of the image formed by a plane mirror?
Answer:
The size of image formed by a plane mirror is same as that of the object infront of the mirror.

Question 7.
What is Newton’s disc?
Answer:
Newton Disc is a card board disc with seven equal sectors colored red, yellow, orange, green, blue, indigo and violet. When the disc turned quickly, the retina receives the sensation of the spectrum simultaneously and disc appears white.

Question 8.
What is an eclipse?
Answer:
An eclipse is an incident, when any astronomical object is partially or fully obscured due to the placement of another astronomical object in the presence of light.

Question 9.
What is light?
Answer:
Light is type of energy, that helps us to see all the things around us.

VII. Short Answer.

Question 1.
What is natural sources of light? Give example.
Answer:
Sources which emit light naturally are known as natural sources of light. The Sun is the primary and the major source of natural light.

Question 2.
Mention the properties of light.
Answer:
Light has some fundamental properties as mentioned below.

• Rectilinear propagation of light
• Reflection
• Speed
• Interaction of light with matter.

1. Types of material according to permeability.
2. Formation of shadows.
3. Plane mirror and images.
4. Spectrum.

Question 3.
State laws of reflection.
Answer:
Laws of reflection:

1. The angle of incidence is always equal to the angle of reflection. \(\lfloor i\) = \(\lfloor r\)
2.  The incident ray, the reflected ray and the normal at the point of incidence lie on the same plane.

Question 4.
Define transparent materials. Give example.
Answer:

1. Materials that allow light to pass through completely are known as transparent material.
2. Example: Eye glasses, clear drinking glass, clear water, face glasses used in buses.

Question 5.
Define opaque material. Give example.
Answer:

1. Materials that are not able to allow light to pass through, are called opaque material.
2. Example: Wall, thick card board, stone, etc.

Question 6.
What is lunar eclipse?
Answer:

1. Lunar eclipse occurs, when the Earth (E) comes between the Sun (S) and the Moon (M).
2. The Earth prevents light coming from the Sun and makes shadow on the Moon. This is lunar eclipse.

Question 7.
Why danger lights in vehicles are red in colour?
Answer:

1. Red color is scattered the least by air molecules.
2. Red color has the highest wavelength of all the other colors. So red color is able to travel the longest distance through air, fog.

Question 8.
What is meant by synthesis of colour?

1. Synthesis of colour is the method of creating colour by mixing various proportion of two (or) three distinct colours of light. .
2. These distinct colours are Red, Green and Blue called as primary colours.

Question 9.
When lighting a bulbs in a dark room, light spreads the whole room quickly. Give reason.
Answer:

1. When lighting a bulb in a dark room, light spreads the whole room quickly.
2. This is because the light travels very fast.
3. Light travels three lakh kilometers per second in air or vacuum.
4. In theory, nothing can travel faster than light.

VIII. Long Answer:

Question 1.
Write the difference between real image and virtual image.
Answer:

	Real image	Virtual image
1.	It can be taken on a screen.	It cannot be taken on a screen.
2.	The rays of light, after reflection	The rays of light, after reflection appear to
3.	It is always inverted	It is always erect but laterally inverted

Question 2.
Explain the importance of optical fiber.
Answer:

1. Optical fiber is a device that works on the principle of total internal reflection by which light signals (huge data) can be transmitted from one place to another place with a negligible loss of energy in a very short time.
2. It consists of a cable having one or more thin flexible fibers with a glass core through which light signals can be sent.
3. Optical fiber can be twisted and bent easily.
4. When a light a ray of light is incident at one end of the core of optical fiber, it suffers total internal reflection at the many places inside the fiber and emerges at the other end with negligible loss of energy.
5. The data or information in the form of pulses of light, can be sent through bundles of optical fibers.
6. Optical fibers have become very important in high-speed communications, such as cable TV and high-speed broadband services.Fiber optic cables are able to carry more signals than traditional copper cable telephone lines.

Question 3.
With help of a diagram, write a note on : a. Solar eclipse, b. Lunar eclipse.
Answer:
(a) Solar eclipse

Solar eclipse occurs, when the Moon arrives between the Sun (S) and the Earth(E). The shadow of the Moon appears on the Earth at A as shown in picture. Hence, those who are at the region A are unable to see the Sun instantly. This is solar eclipse. But, those who are at the region B and C are able to see the sun partially.
(b) Lunar eclipse

Lunar eclipse: Lunar eclipse occurs, when the Earth (E) comes between the Sun (S) and the Moon (M). The Earth prevents light coming from the Sun and makes shadow on the Moon. This is lunar eclipse

IX. Problems for practice:

Question 1.
Calculate the number of images formed by plane mirrors kept at an angle of 10° to each others.
Solution:
Number of image n = \(\frac { 360° }{ θ}\) – 1 = \(\frac { 360° }{ 10°}\) – 1
= 36 – 1
= 35 images

Question 2.
A ray of light fall on a plane surface at an angle of incidence 9° and reflection occurs. Calculate the angle of reflection in degree.
Solution:
By first law of reflection, angle of incidence is always equal to angle of reflection.
\(\lfloor i\) = \(\lfloor r\) . Here, angle of incidence is 9°. So angle of reflection must be equal to 9°.

Question 3.
A plane mirror forms a virtual image. The distance between Maria and her image in a plane mirror is 10 m. How much distance should she move in order to get the distance of 5 m between herself and her image?
Solution:

The distance between Maria and her image in a plane mirror = 10 m

So, she shouuld move a distance of 2.5 m toward the plane mirror

X. Higher order thinking skill (HOTS) :

Question 1.
Why are we able to see the tap water in a glass even though it is colourless?
Answer:
Top water reflects the light into our eyes. As long as an object reflects light into our eyes, we can see it.

Question 2.
Imagine that parallel rays are incident on an irregular surface. Are the rays reflected from this surface parallel to each other?
Answer:
No, the reflected rays from irregular surface are in different directions.

Question 3.
Ram planned an activity to observe an object through pipes as shown in figure, so that he could see objects which he could not directly see.

(a) Mention how many mirrors should he use to see the objects.
(b) If any of the mirrors is removed, will he be able to see the objects?
(c) Indicate the positions of the mirrors in the figure.
Answer:
(a) Number of mirrors = 3
(b) He will not be able to see the objects if any of the mirror is removed, since he will not get the rays after removal of mirror.

Students can Download Tamil Chapter 1.2 கவின்மிகு கப்பல் Questions and Answers, Summary, Notes Pdf, Samacheer Kalvi 7th Tamil Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 7th Tamil Solutions Term 2 Chapter 1.2 கவின்மிகு கப்பல்

மதிப்பீடு

சரியான விடையைத் தேர்ந்தெடுத்து எழுதுக.

Question 1.
இயற்கை வங்கூழ் ஆட்ட – அடிக்கோடிட்ட சொல்லின் பொருள்
அ) நிலம்
ஆ) நீர்
இ) காற்று
ஈ) நெருப்பு
Answer:
இ) காற்று

Question 2.
மக்கள் ………………….. ஏறி வெளிநாடுகளுக்குச் சென்றனர்.
அ) கடலில்
ஆ) காற்றில்
இ) கழனியில்
ஈ) வங்கத்தில்
Answer:
ஈ) வங்கத்தில்

Question 3.
புலால் நாற்றம் உடையதாக அகநானூறு கூறுவது ……………….
அ) காற்று
ஆ) நாவாய்
இ) கடல்
ஈ) மணல்
Answer:
இ) கடல்

Question 4.
‘பெருங்கடல்’ என்னும் சொல்லைப் பிரித்து எழுதக் கிடைப்பது
அ) பெரு + கடல்
ஆ) பெருமை + கடல்
இ) பெரிய + கடல்
ஈ) பெருங் + கடல்
Answer:
ஆ) பெருமை + கடல்]

Question 5.
இன்று + ஆகி என்பதனைச் சேர்த்தெழுதக் கிடைக்கும் சொல் …….
அ) இன்று ஆகி
ஆ) இன்றி ஆகி
இ) இன்றாகி
ஈ) இன்றா ஆகி
Answer:
இ) இன்றாகி

Question 6.
எதுகை இடம்பெறாத இணை ………..
அ) இரவு – இயற்கை
ஆ) வங்கம் – சங்கம்
இ) உலகு – புலவு
ஈ) அசைவு – இசைவு
Answer:
அ) இரவு – இயற்கை

பொருத்துக

1. வங்கம் – பகல்
2. நீகான் – கப்பல்
3. எல் – கலங்கரை விளக்கம்
4. மாட ஒள்ளெரி – நாவாய் ஓட்டுபவன்
Answer:
1. வங்க ம் – கப்பல்
2. நீகான் – நாவாய் ஓட்டுபவன்
3. எல் – பகல்
4. மாட ஒள்ளெரி – கலங்கரை விளக்கம்

குறுவினா

Question 1.
நாவாயின் தோற்றம் எவ்வாறு இருந்ததாக அகநானூறு கூறுகிறது?
Answer:
நாவாயின் தோற்றம் : உலகம் புடைபெயர்ந்தது போன்ற அழகு பொருந்திய தோற்றத்தை உடையது நாவாய் என்று அகநானூறு நாவாயின் தோற்றத்தைப் பற்றி கூறுகிறது.

Question 2.
நாவாய் ஓட்டிகளுக்குக் காற்று எவ்வாறு துணை செய்கிறது?
Answer:
இரவும் பகலும் ஓரிடத்தும் தங்காமல் வீசுகின்ற காற்றானது நாவாயை அசைத்துச் செலுத்தி நாவாய் ஓட்டிகளுக்கு உறுதுணையாக நிற்கிறது.

சிறுவினா

கடலில் கப்பல் செல்லும் காட்சியை அகநானூறு எவ்வாறு விளக்குகிறது?
Answer:

• உலகம் புடைபெயர்ந்தது போன்ற அழகு பொருந்திய தோற்றத்தை உடையது நாவாய்.
•  அந்த நாவாய் புலால் நாற்றமுடைய அலைவீசும் பெரிய கடலின் நீரைப் பிளந்து கொண்டு செல்லும்.
• இரவும் பகலும் ஓரிடத்தும் தங்காமல் வீசுகின்ற கடற்காற்றானது நாவாயை அசைத்துச் செலுத்த பெரிதும் துணை புரிகின்றது.
• உயர்ந்த கரையை உடைய மணல் நிறைந்த துறைமுகத்தில் கலங்கரை விளக்கத்தின் ஒளியால் திசை அறிந்து நாவாய் ஓட்டுபவன் நாவாயைச் செலுத்துவான் என்று அகநானூறு கடலில் கப்பல் செல்லும் காட்சியை விளக்குகிறது.

சிந்தனை வினா

தரைவழிப் பயணம், கடல்வழிப் பயணம் ஆகியவற்றுள் நீங்கள் விரும்புவது எது? ஏன்?
Answer:

• நான் விரும்பும் பயணம் கடல்வழிப் பயணம்.
• ஏனென்றால் கடலில் செல்லும் போது கடலில் வீசும் இதமான காற்று உடலை வருடிச் செல்லும். மேலும் கீழுமாக தாவிச் செல்லும் அலைகள் காண்பதற்கு கவினுற அமைந்திருக்கும்.
• கடலில் வாழும் பல்வகை மீன்கள் கடல் நீரில் நீந்திச் செல்லும் காட்சி பார்ப்பதற்கு மிக அழகாக இருக்கும்.
• இரவு நேரத்தில் கப்பலிலிருந்து ஆகாயத்தைப் பார்க்கும் போது பல்வகை விண்மீன்கள் மற்றும் நிலவு நம்முடனே பயணிப்பது போன்ற தோற்றம் நம்மை மகிழ்ச்சியில் ஆழ்த்தும்.

கற்பவை கற்றபின்

Question 1.
கடலில் கிடைக்கும் பொருள்களின் பெயர்களைத் தொகுக்க.
Answer:
கடலில் கிடைக்கும் பொருட்களின் பெயர்கள் :

• பல்வகை மீன்கள், சிப்பிகள், சங்குகள், நண்டுகள் கடலின் மூலம் கிடைக்கின்றன.
• சுண்ணாம்பு. மணல், சரளை போன்ற பொருட்கள் மற்றும் கடல் அடிவாரத்தில் கரைந்துள்ள கனிமங்கள்.
• கச்சா எண்ணெய் மற்றும் எரிவாயு.
• கடல் நீரில் இருந்து உப்பு கிடைக்கிறது.
• கடல்வாழ், உயிரினங்களில் முத்துக்களை உற்பத்தி செய்யும் திறனுடைய யூனியோ, க்வாட்ருலா என்ற பெயருடைய சிப்பிகள் உள்ளன.
• ஆழ்கடலில் எடுக்கப்படும் முத்து உயர் ரகமாகும். முத்தை அணிந்தால் முத்து உடலில் பட்டு கரையும். அப்போது உடல் சூடு நீங்கும் என மருத்துவர்கள் குறிப்பிடுகின்றனர்.

Question 2.
கடற்பயணம் பற்றிய சிறுகதை ஒன்றை அறிந்து வந்து வகுப்பறையில் பகிர்க.
Answer:
மாணவர்கள் தாங்களாகவே செய்ய வேண்டியவை.

கூடுதல் வினாக்கள்

சொல்லும் பொருளும் :

1. உரு – அழகு
2. வங்கம் – கப்பல்
3. போழ – பிளக்க
4. எல் – பகல்
5. வங்கூழ் – காற்று
6. கோடு உயர் – கரை உயர்ந்த
7. நீகான் – நாவாய் ஓட்டுபவன்
8. மாட ஒள்ளெரி – கலங்கரை விளக்கம்

சரியான விடையைத் தேர்ந்தெடுத்து எழுதுக.

Question 1.
‘உரு’ என்பதன் பொருள் …..
அ) நாவாய் ஓட்டுபவன்
ஆ) கப்பல்
இ) கரை உயர்ந்த
ஈ) அழகு
Answer:
:ஈ) அழகு

Question 2.
‘போழ’ என்பதன் பொருள் …………………
அ) பிளக்க
ஆ) காற்று
இ) கப்பல்
ஈ) கலங்கரை விளக்கம்
Answer:
அ) பிளக்க

Question 3.
‘வங்கூழ்’ என்பதன் பொருள் ……………….
அ) காற்று
ஆ) அழகு
இ) பிளக்க
ஈ) பகல்
Answer:
அ) காற்று

Question 4.
‘நீகான்’ என்னும் சொல்லுக்கு …………………………. என்பது பொருள்.
அ) நாவாய் ஓட்டுபவன்
ஆ) கலங்கரை விளக்கம்
இ) பகல்
ஈ) கப்பல்
Answer:
அ) நாவாய் ஓட்டுபவன்

Question 5.
‘வங்கம்’ என்பதன் பொருள் ……………….
அ) கப்பல்
ஆ) பகல்
இ) அழகு
ஈ) காற்று
Answer:
அ) கப்பல்

Question 6.
கோடு உயர் என்பதன் பொருள் ……………..
அ) கரை உயர்ந்த
ஆ) கப்பல்
இ) காற்று
ஈ) பிளக்க
Answer:
அ) கரை உயர்ந்த

Question 7.
மாட ஒள்ளெரி என்பதன் பொருள் ………………
அ) கலங்கரை விளக்கம்
ஆ) பிளக்க
இ) கரை உயர்ந்த
ஈ) காற்று
Answer:
அ) கலங்கரை விளக்கம்

விடையளி:

Question 1.
அகநானூறு எட்டுத்தொகை நூல்களுள் ஒன்றா?
Answer:
ஆம். இது எட்டுத் தொகை நூல்களுள் ஒன்று.

Question 2.
எட்டுத் தொகை நூல்களை வரிசைப்படுத்துக:
Answer:
நற்றிணை, குறுந்தொகை, ஐங்குறுநூறு, பதிற்றுப்பத்து, பரிபாடல், கலித்தொகை, அகநானூறு, புறநானூறு.

Question 3.
மருதன் இளநாகனார் குறிப்பு வரைக.
Answer:

• மருதன் இளநாகனார் சங்ககாலப் புலவர்களுள் ஒருவர்.
• கலித்தொகையின் மருதத்திணையில் உள்ள முப்பத்தைந்து பாடல்களையும் பாடியவர்.
• மருதத்திணை பாடுவதில் வல்லவர் என்பதால் மருதன் இளநாகனார் என அழைக்கப்படுகிறார்.

பாடலின் பொருள்

உலகம் புடைபெயர்ந்தது போன்ற அழகு பொருந்திய தோற்றத்தை உடையது நாவாய். அது புலால் நாற்றமுடைய அலைவீசும் பெரிய கடலின் நீரைப் பிளந்து கொண்டு செல்லும். இரவும் பகலும் ஓரிடத்தும் தங்காமல் வீசுகின்ற காற்றானது நாவாயை அசைத்துச் செல்லும். உயர்ந்த கரையை உடைய மணல் நிறைந்த துறைமுகத்தில் கலங்கரை விளக்கத்தின் ஒளியால் திசை அறிந்து நாவாய் ஓட்டுபவன் நாவாயைச் செலுத்துவான்.

You can Download Samacheer Kalvi 7th Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 7th Science Solutions Term 2 Chapter 4 Cell Biology

Samacheer Kalvi 7th Science Cell Biology Textual Evaluation

I. Choose the correct answers:

Cell Biology 7th Standard Question 1.
Basis unit of life.
(a) Cell
(b) Protoplasm
(c) Cellulose
(d) Nucleus
Answer:
(a) Cell

7th Science Cell Biology Question 2.
the outer most layer of an animal cell. Who am I?
(a)Cell wall
(b) Nucleus
(c)Cell membrane
(d) Nuclear membrane
Answer:
(c) Cell membrane

Samacheer Kalvi 7th Biology Guide Question 3.
Which part of the cell is called the brain of the cell?
(a) Lysosome
(c) Mitochondria
(b) Ribosome
(d) Nucleus.
Answer:
d) Nucleus

Science Cell Biology Question 4.
________ helps in cell division.
(a) Endoplasmic reticulum
(b) Golgi complex
(c) Centriole
(d) Nucleus
Answer:
(c) Centriole

Samacheer Kalvi Guru Science 7th Question 5.
Suitable term for the various components of cell is _________
(a) Tissue
(b) Nucleus
(c) Cell
(d) Cell organelle
Answer:
(d) Cell organelle

Fill in the blanks:

1. The jelly like substance present in the cell is called _______.
2. I convert the Sun’s energy into food for the plant. Who am I?_________.
3. Mature Red blood cell do not contain a ________.
4. Unicellular organisms can only be seen under a ________.
5. Cytoplasm plus nucleoplasm is equal to ________.

Answer:

1. cytoplasm
2. chloroplast
3. Nucleus
4. Microscope
5. Protoplasma

III. True or False – If False give the correction answer

7th Biology Guide Question 1.
Animal cells have a cell wall.
Answer:
False, Plant cells have a cell wall.

Question 2.
Salmonella is a unicellular bacteria.
Answer:
True

Question 3.
Cell membrane is fully permeable.
Answer:
False, Cell membrane is selectively permeable.

Question 4.
Only plant cells have chloroplasts.
Answer:
True.

Question 5.
Human stomach is an organ.
Answer:
True.

Question 6.
Ribosomes are small organelles with a membrane.
Answer:
False. Ribosomes are small organelles without a membrane.

IV. Match the following:

Question 1.

1. Transporting channel – Nucleus
2. Suicidal bag – Endoplasmic reticulum
3. Control room – Lysosome
4. Power house – Chloroplast
5. Food producer – Mitochondria

Answer:

1. Transporting channel – Endoplasmic reticulum
2. Suicidal bag – Lysosome
3. Control room – Nucleus
4. Power house – Mitochondria
5. Food producer – Chloroplast

V. Analogy:

Question 1.
Bacteria : microorganism :: mango tree :________
Answer:
Macroorganism.

Question 2.
Adipose : tissue :: eye :_________
Answer:
Organ

Question 3.
Cell wall: plant cell:: centriole :_________
Answer:
Animal cell.

Question 4.
Chloroplast: photosynthesis :: mitochondria :________
Answer:
Respiration.

VI. Choose Use connect alternative from the following :

Question 1.
Assertion (A) : Tissue is a group of dissimilar cells.
Reason (R) : Muscle is made up of Muscle cell.
(a) Both A and R are true
(b) Both A and R are false
(c) A is true but R is false
(d) A is false but R is true
Answer:
(a) Both A and R are true

Question 2.
Assertion (A) :Majority of cells cannot be seen directly with naked eye because.
Reason (R) :Cells are microscopic.
(a) Both A and R are true
(b) Both A and R are false
(c) A is true but R is false.
(d) A is false but R is true.
Answer:
(a) Both A and R are true

VII. Very short answer:

Question 1.
What are the functions of cell wall in plant cell?
Answer:
Protection, maintains shape of cell and acts as protective framework.

Question 2.
Which organelle uses energy from sunlight to make starch?
Answer:
Chloroplast uses energy from sunlight to make starch.

Question 3.
What are the main things in a nucleus?
Answer:
Nuclear envelope, Nucleolus, chromatin body.

Question 4.
What does cell membrane do?
Answer:
It acts as boundary of cell and protects it.

Question 5.
Why lysosomes are known as scavengers of the cell?
Answer:
The lysosomes are the main digestive compartments of a cell and digest damaged cell parts. Hence they are called scavengers of the cell.

Question 6.
Teacher said “A virus is not an organism” Do you agree with this statement or
not? Explain Why?
Answer:
True I agree with the statement. A virus acts as a living organism within the body of a host and behaves like a non-living thing outside. It lacks cell wall, cell membrane, cytoplasm and organelles. Hence it is not a organism.

VII. Give short answer :

Question 1.
Why the cell is very important for us?
Answer:

1. Cell is the basic structural and functions unit of life.
2. It is the building unit of living organism.
3. A group of cells form a tissue which forms the organ and organ systems.
4. This helps a living organism to do its functions. Hence cell is very important for us.

Distinguish between the following pairs

• Smooth ER and Rough ER
• Cell wall and cell membrane
• Chloroplast and mitochondria

Answer:
Smooth ER (Endoplasmic Reticulum)

1. It is smooth due to absence of Ribosomes.
2. It helps in transport of steroids and lipids.

Rough ER (Endoplasmic Reticulum)

1. It is’rough due to presence of Ribosomes.
2. It helps in protein synthesis

Cell wall

1. It is seen only in plant cells.
2. It is made of cellulose.

Cell membrane

1. It is seen in plant and animal cells.
2. It is made of proteins and lipids.

Chloroplast

1. It is a organelle seen only in plant cells (green plants)
2. It helps in synthesis and storage of starch.

Mitochondria

1. It is a organelle seen in plant and animal cells.
2. It is the centre of respiration in a cell and produces energy.

Question 3.
Write correct sequence from cell to organism?
Answer:
Cell —> Tissue —> Organ —> Organ system —> Organism.

Question 4.
Write a short note on nucleus.
Answer:

1. Nucleus is seen in the cytoplasm of plant and Animal cells.
2. It is surrounded by nuclear envelope.
3. It has one or two nucleoli and chromatin body.
4. The chromatin body stores genetic information.

Functions of Nucleus:

1. It controls all the processes and chemical reactions that take place inside the cell.
2. Inheritance of character from one generation to another.

Question 5.
Classify the following terms into cells, tissues, organs and write in the tabular column given below:
Neuron, Lungs, Xylem, brain, adipose, Leaf, RBC, WBC, hand, muscle, heart, ovum, squamous, phloem, cartilage.
Answer:

Cell	Tissue	Organ
Neuron	Xylem	Lungs
RBC	Adipose	Brain
WBC	Muscle	Leaf
Ovum	Squamous	Hand
	Phloem	Heart
	Cartilage

Question 6.
On the lines given below, write about what you have learned from the activities done in this lesson.
Let me tell you about some of the important things I’ve learned about cells. First, I’ll start with… .
First, I’ll start with___________________________.
Answer:

1. Cell is the basic unit of an organisms.
2. Based on number of cells organisms can be classified as unicellular and multicellular organisms.
3. The cells form tissues, Tissues form organs, Organ system help an organism to function.
4. The cell wall is seen only in plant cells.
5. Cell membrane is seen only in plant cells.
6. Cell membrane is seen in all cells.
7. The organelles of the cell like chloroplast, Mitochondria, Ribosomes, Endoplasmic Reticulum, Golgi bodies etc help to perform cell functions.
8. Nucleus is the controlling centre of a cell.

IX. Given long answer:
Question 1.
Write about any three organelles in detail.
Answer:
The three organelles are as follows
Chloroplasts:

1. They are green organelles seen in plant cells only.
2. They can prepare food using sun is energy and photosynthesize since they contain the pigment chlorophyll.
3. They absorb the radiant energy of the sun and convert it to chemical energy to be used by plants and animals.

Golgi Complex:

1. They are cell organelles which consist of membrane bound sacs stacked on top of one another and have associated secretory vesicles.
2. Golgi complex helps in production of secretory substances, packaging and secretion.

Mitochondria:

1. It is a oral double membrane bounded organelle.
2. Aerobic respiration occurs in mitochondria and energy is released. Hence mitochondria is called as power house of the cell
3. The energy produced is used for metabolic activities of the cell.

Question 2.
In a situation, how to explain, while your friend ask what is this, never seen before ?

Answer:

1. This is a animal cell.
2. It is the basic unit of an animal body.
3. Animal cell is covered by a cell membrane and lacks cell wall.
4. It has organelles like mitochondia, Golgi apparatus, Ribosomes, etc..
5. It differs from plant cells since it lacks chloroplast.
6. It has centrioles which are not seen in plant cells.
7. Nucleus is the controlling centre of the cell.

Question 3.
Compare the plant cell and the animal cell and complete the illustration given below
Answer:

X. Higher ordear Thinking question :
Virus is called Acellular. Why?
Answer:

1. Virus is made up of a outer protein coat and a nucleic acid.
2. It lacks cell wall, cell membrane, organelles and cytoplasm.
3. Therefore a virus is described as a cellular.

Samacheer Kalvi 7th Science Cell Biology Intext Activities

Activity – 1

Question 1.
Do you remember the lesson studied in previous class, how will you find whether an object is living or non – living? Write it down. An object is living or non-living?
Answer:
Living things: Living things use energy. They move or change shape.
Eg: Humans, insects, plants, animals etc.
Non-living things:
Do not move by themselves, grow or reproduce.
Eg: Rocks, car, pencils etc.

Question 2.
Form a team and work together to write down some of the functions of life, which you can remember.
Answer:
Reproduction, response to stimuli, Growth, movement, excretion

Question 3.
Do you think that an individual cell is living? Explain your answer.
Answer:
Cells are living things. Cells are found in plants, animals and Bactria.

Question 4.
Write about various organelles of a cell which you know.
Answer:
Vacuole, lysosome, endoplasmic reticulum, Golgi appartus, mitochondria, chloroplast.

Activity – 2
Find out major organs that are part of the circulatory system of a human body and list out their functions.
Answer:

Organs

1. Heart (Cardiovascular)
2. Lungs (Pulmonary)
3. Blood vessels – Arteries
4. Blood vessels – Veins

Functions

1. Pumps oxygenated and deoxygenated blood on different sides.
2. In oxygen from incoming air enters the blood and carbon-di-oxide, a waste gas from the metabolism, leaves the blood.
3. Carry blood away from the heart.
4. Carry blood back to the heart.

Activity – 3
Study the pictures given and write the differences between cells that you observe in the given table
Answer:

Activity – 4
Summarise what you have learnt Now you’ve studied the internal structure of a cell. Let us summerise what we have learnt so far Complete this table by filling the main function of each of the cell structures.

Cell Structure

1. Cell membrane
2. Cell wall
3. Cytoplasm
4. Mitochondria
5. Vacuole
6. Chloroplast
7. Endoplasmic reticulum

Function(s)

1. Boundary of an animal cell.
2. Supporter and protector.
3. Giving a ceil its shape.
4. Energy releaser.
5. Support the organelle.
6. Food producers.
7. Synthesis protein lipids, steroids and transport them

Samacheer Kalvi 7th Science Cell Biology Additional Question :

Choose the correct answer.

Question 1.
________ is the largest organelle
(a) Chloroplast
(b) Mitochondria
(c) Nucleus
(d) Golgi apparatus
Answer:
(c) Nucleus

Question 2.
The ______cells are spindle shaped.
(a) muscle
(b) nervous
(c) RBC
(d) epithelial
Answer:
(a) muscle

Question 3.
The________ plays a role in change of colour and taste of fruits.
(a) nucleus
(b) Golgi bodies
(c) lysosome
(d) chloroplast
Answer:
(b) Golgi bodies

Question 4.
________lacks a nucleus.
(a) Nerve cell
(b) Muscle cell
(c) RBC
(d) Brain cell
Answer:
(c) RBC

Question 5.
Starch is stored in _______
(a) chloroplast
(b) leucoplast
(c) chromoplast
(d) Golgi apparatus
Answer:
(b) leucoplast

II. Fill in the blanks.

1. Plastids containing coloured pigments are called ________
2. cells have the ability to multiply and develop into different types of cells.
3. ________are seen only in animal cells.
4. An organelle seen in bacteria and cell of higher organisms is ______
5. Cell wall is made up of ________

Answer:

1. Chromoplasts
2. stem
3. centrioles
4. Ribosome
5. cellulose

III. True or false – if false, give the correct statement.
Question 1.
Leucoplast store steroids.
Answer:
False, Leucoplasts store starch.

Question 2.
Bacteria is a animal cell.
Answer:
False, Bacteria is a plant cell.

Question 3.
Amoeba contains chloroplants.
Answer:
False, Amoeba does not contain chloroplasts.

Question 4.
Mitochondria can help to photosynthesize.
Answer:
False, Mitochondria can help to produce energy

Question 5.
The cytoplasm consists of 90% water.
Answer:
True

Question 6.
The body of a nerve cell is branched.
Answer:
True.

IV. Match the following:

Question 1.

Answer:
(c)
(d)
(b)
(a)

V. Analogy:

Question 1.
Golgi: secretion :: Endoplasmic reticulum: _________
Answer:
Transport.

Question 2.
Plant tissue : Xylem :: Animal tissue : _________
Answer:
Epithelium.

Question 3.
Plant organ : stem :: Animal organ : _________
Answer:
Stomach.

VI. Assertion and Reason.
Mark the correct choice as
(a) Both A and R are true.
(b) Both A and R are false
(c) A is true but R is false.
(d) A is false but R is true

Question 1.
Assertion (A) : Stem cells can form different types of cells.
Reason (R) : They are found in plants and animals.
Answer:
(c) A is true but R is false

Question 2.
Assertion (A): The cell wall has pores.
Reason (R) : Each cell is connected to its neighbouring cell.
Answer:
(a) Both A and R are true

VII. Very short Answers:

Question 1.
Define a tissue.
Answer:
Tissue is a group of cells organized for a specific function.

Question 2.
What is Plasmodesmata?
Answer:
Each plant cell is interconnected with its neighboring cells through openings called Plasmodesmata.

Question 3.
What is ATP?
Answer:
ATP stands for Adenosineri Phosphate and is the energy currency of a cell.

Question 4.
What is unique about embryonic stem cells?
Answer:
They can develop into any type of cell in the body. Such as blood cell, nerve cell etc.

Question 5.
Name the types of plastids.
Answer:
Chloroplasts, chromoplasts and leucoplasts.

Question 6.
Name a cell which lacks a nucleus.
Answer:
Red blood cell.

VII. Short Answer.

Question 1.
Why are lysosomes called as ‘suicidal bags of the cell’?
Answer:
Lysosoms can lyse (destroy) a cell by producing enzymes. Hence they are known as suicidal bags of the cell.

Question 2.
What is endoplasmic reticulum?
Answer:
It is an inter membranous network made up of flat or tubular sacs within the cytoplasm. Endoplasmic reticulum is of two types. They are rough endoplasmic reticulum and smooth endoplasmic reticulum

Question 3.
List the functions of Nucleus.
Answer:

1. It controls all the processes and chemical reactions that take place inside the cell.
2. Inheritance of character from one generation to another.

Question 4.
Why is mitochandia known as power house of the cell?
Answer:
Aerobic respiratory reactions take place within the mitochondrion to release energy. So it is known as “The Power House’” of the cell.

Question 5.
What is a vacuole?
Question:
It is a membrane bound bag like structure filled within organic and organic molecules along with water and found in plant cells to support the organelles. Animal cell has very small vacuoles.

VIII. Long Answer

Question 1.
List the functions of cell wall.
Answer:

1. Cell wall provides a frame work for support and stability.
2. It allows the plant to remain rigid and upright.
3. It helps to maintain the shape of the plant cell.
4. It has openings called plasmodesmata through which neighboring cells are interconnected.
5. It acts as a protective covering for the cell.

Question 2.
Draw a plant cell and label the parts.
Answer:

Question 3.
List the differences between Plant cell and Animal cell.
Answer:

Plant cell

1. It has cell wall.
2. It has plastids such as chloroplasts, chromoplasts etc.
3. Centrioles are not seen.
4. It has a large vacuole.
5. It is larger in size.

Animal Cell

1. Cell wall is absent.
2. Plastids are absent.
3. It has centrioles which help in cell division.
4. Vacuoles are small or absent.
5. It is smaller in size.

IX. Hots:

Question 1.
Bacterial cells can prepare food. Do you agree?
Answer:
Yes, some bacterial cells have chlorophyll pigments and can prepare food.

Question 2.
Stem cells are used by doctors to treat diseases. Do you agree with this statement?
Answer:
Yes. Stem cells can divide and form any other cell type and hence can be used to cure several diseases like spinal cord injury.