III CLASS - SCIENCE

Class: III Term – I Science

Ls. 1 Living and Non living things


New words:
Breathe
Minerals
Stomata
Oxygen
Gills
Sensitive
Reproduce

Questions and Answers:

Q. 1. Write the names of four living and non living things.
A. Living things:- Man, tiger, crow, spider, tree etc.
Non Living things:- Pen, chair, shoe, ball, fan etc.

Q. 2. What is a living thing? Give three examples.
A. Things that eat, breathe, move, grow, reproduce and die are called living things.
Ex: Man, rabbit, crow.

Q.3 Can living things live without food? Why?
A. No, living things cannot live without food. They need food to grow and have energy to work.

Q. 4. How do animals breathe?
A. Most of the animals breathe through their lungs. Some animals breathe through air tubes. Fishes breathe through gills.

Q. 5. How do plants breathe?
A. Plants breathe through tiny holes called stomata which are present on the leaves

Q. 6. Write four differences between living and non-living things.
A. Living things Non – Living things

1. Living things breathe in oxygen 1. They do not breathe
2. Living things grow 2. They do not grow
3. Living things reproduce 3. They do not reproduce
4. All living things die after some years 4. They do not die as they do not have
life.

Q. 7. Why do animals and human beings feel hot or cold?
A. Animals and human beings are sensitive. So, they feel hot in summer and cold in winter.

Answers for Reader exercises:-

Fill in the blanks:
1. Non-living
2. Living
3. Cannot
4. Breathe, eat, move, reproduce, die.
5. Birth
6. Oxygen (air)

Tick the true statement and cross the false ones :
1. False
2. True
3. False
4. False
5. True


Ls. 2 Natural and Man Made Things


New words:
1. Carpenter
2. Natural
3. Artificial
4. Vessels
5. Furniture
6. Vehicles

Answer the following questions :

Q. 1. Write three points about natural things.
A. Natural things are not made by man. They occur in nature.
(a) Natural things may be non-living. Ex. Sun, moon, mountains etc.
(b) Natural things may be living. Examples. Lion, Tree.

Q. 2. Write two things that man-made things can’t do.
A. (a) All man-made things are non-living. So, they cannot grow.
(b) Man-made things cannot reproduce.

Exercises (Text Book):

Tick the man made things from this list.

1. Car 2. Cycle 3. Table 4. Telephone 5. Computer

Match the following :

1. lay eggs
2. Prepares its own food
3. Stomata
4. Gills
5. Cannot make their own food

Choose the correct answer :

1. gills
2. grow
3. cannot
4. have
5. reproduce


Ls. 3 Similarities between Plants and Animals

New words :
1. similar
2. breathe
3. reproduce
4. chlorophyll
5. stomata
6. seedlings
7. minerals

Questions and Answers:

Q. 1. What are the similarities between animals and plants?
A. The similarities between animals and plants are:
i) Both need food to eat and grow.
ii) Both need water.
iii) Both can feel and breathe.
iv) Both can reproduce.
v) Both die after a period of time.

Q. 2. Can animals make their own food? How do they find food?
A. No, animals cannot make their own food. They eat plants or search other animals and eat them.

Q. 3. Why don’t plants move from place to place looking for food?
A. Plants do not move from place to place for food because they can make their own food with the help of water, chlorophyll and sunlight.

Q. 4. Define stomata.
A. Stomata are tiny holes on the surface of leaves. They are like lungs of the plants and help the plant in breathing.

Q.5. Can man live without animals and plants? What will happen to him?
A. No, man can not live without plants and animals. Without them, he would die due to lack of food. So, man depends on them for his survival.



Q. 6. What are the differences between animals and plants?
Plants
1. Plants do not move in search of food and shelter.
2. They make their own food.
3. They do not have sense organs.
4. They breathe through tiny holes called stomata in their leaves.
5. They reproduce mainly through seeds.
Animals
1. Animals move in search of food and shelter.
2. They do not make their own food.
3. They have sense organs.
4. They have breathing organs like gills, air tubes and lungs.
5. They reproduce by giving birth to young ones or by laying eggs.


7. Describe the following :
(a) Sense organs (b) Cutting
A.
(a) Sense organs : The organs by which human beings and animals can sense and feel are called sense organs.
(b) Cutting : A small branch, cut from a plant is called cutting. When the cutting is planted in the soil, it grows into a new plant.


Answers for the reader exercises:
Fill in the blanks:
1. Water and minerals
2. Sunlight
3. Seeds
4. Root, stem
5. Eggs
6. Young ones

Match the following:

a. Fish-swim-breathe through gills.
b. Birds-fly-look for food.
c. Plants-green-make their own food.

D] 3.
a. in the soil.
b. Daily
c. Seedling
d. Towards sunlight
e. Branches
f. Tree

Diagrams : Reproduction in plants – seed, seedling, small plant.




Ls. 4 Plant Life

New Words :
1. root
2. shoot
3. fibrous root
4. firmly
5. branches
6. chlorophyll
7. photosynthesis
8. fragrance
9. reproduce

Question and Answers:-

1. What is a tap root?
A. Tap root has one main root which grows below the soil. It is continuation of the stem. It has number of thin and small roots.
Ex : Neem, Mango.


2. What is a fibrous root?
A. Fibrous roots are a bunch of small roots growing from below the stem.
Ex : roots of grass.

3. Give any two functions of the stem.
A. The two functions of the stem are:
a) It helps the plant to stand upright.
b) It carries water and minerals from the roots to the different parts of the plants.

4. Give any two functions of the leaf.
A. The two functions of a leaf are:
1. It helps the plants to breathe.
2. It helps the plants to make food.

5. Why is the leaf called the ‘Kitchen of the Plant’?
A. Leaves make food for the plant by the process of photosynthesis by using
sunlight, air, water and chlorophyll. Therefore, leaves are called the ‘Kitchen of
the Plant’.


6. Write short notes on a) flowers b) fruits c) seeds.
A.
Flowers: They are of many colours, shapes and sizes. Many flowers have a lovely fragrance. Most flowers become fruits and they also help the plant to reproduce. Rose, lotus, marigold, sunflower are some common flowers.

Fruits: Fruits grow from flowers. They also come in different shapes and sizes. We eat fruits. Ex:- Mango, apple, orange, banana etc.

Seeds: Plants reproduce through seeds. Seeds hold the baby plant inside them. When a seed is planted in soil and watered regularly, it grows into a seedling with the help of sunlight. Seeds also store food for the baby plant. Most fruits have seeds.

Answers for Reader exercises:-

Fill in the blanks:

1. above
2. below
3. two
4. fibrous
5. soil
6. shoot
7. stem

True or False:

1. True 2. False 3. False 4. False 5. True 6. False

Match the following:-

1. Make the plant stand firmly in the soil.
2. Carries water and minerals to the different parts of the plants.
3. Grow from the stem above the ground.
4. Tiny holes on the leaves that help the plant to breathe.
5. Help the plant to reproduce.


Give examples:

1. Rose, Mango
2. Wheat, grass
3. Carrot, beet root
4. Potato, ginger
5. Cabbage, spinach
6. Mango, cherry
7. Watermelon, papaya
8. Orange, apple

Diagrams : Kinds of roots, Tap root, fibrous root with examples.


Ls. 5 Trees - Man’s Best Friend


New words :

1. medicine
2. fibre
3. pulp
4. rubber
5. shelter
6. herb
7. benefits

Question and Answers :

1. In how many ways do trees help us?
A. Trees help us in many ways.
1. They give us fruits and vegetables.
2. They give us fibre from which we weave cloth.
3. We get paper from plants like bamboo.
. They give us herbs from which we make medicine.
5. They give shelter to animals.
6. They give out oxygen and make the air pure for breathing.
7. They help to protect the soil from being washed away by rain.
8. They give us gum and rubber.


2. What must we do to save the trees?
A. We can do the following to save the trees.
1. Plant more trees.
2. Water the plants.
3. Do not cut trees.
4. Teach people about the value of trees.


Text book exercise:

Fill in the blanks:
1. cloth
2. rubber
3. storing water
4. oxygen
5. bamboo


Ls. 6 Animal Life

New words :
1) herbivores
2) carnivores
3) omnivores
4) incisors
5) molar
6) canine
7) slurp
8) nibble
9) gnawing
10) reproduce
11) nectar
12) stable
13)kennel
14)coop
15)domestic


Question and Answers:-

1. Name the kinds of teeth that a herbivore has.
A. A herbivore has incisors (cutting teeth) and molars (grinding teeth).

2. What does a carnivore eat?
A. A carnivore eats flesh of other animals.

3. What is the name of the group of animals that eat both animal and plant food?
A. Omnivores eat both animal and plant food.

4. What is a natural shelter?
A. Some animals do not build homes. They live on trees, in caves and where there are many trees. These are known as natural shelters.

Fill in the blanks:

hole
nests
dens
trees
domestic animals
kennels

Match the following:
cutting teeth
grinding teeth
eat both plants and animals
to chew meat and bone

Name an animal against each one of the following homes:
Monkey
Dog
Rats
Hen
Tiger
Horse



Ls. 7 Movements of Animals

New words:
1. amphibian
2. locomotion
3. locomotory organs
4. adaptation
5. mammals
6. bellies
7. reproduce
8. crawl
9. stretches

Question and Answers:

1. What is the movement of animals called?
A. The movement of animals is called locomotion.

2. Why does a frog have short fore legs but long hind legs?
A. Frogs have short fore legs and long hind legs because they help the frog to swim in water as well as to move on land.

3. State the function of the gills in fishes.
A. The gills help the fish to breathe.

4. How do reptiles reproduce?
A. Reptiles reproduce by laying eggs.

5. Write the names of four parts of a bird’s body.
A. The four parts of bird’s body are beak, wings, feathers and legs.

6. What are Mammals? Give examples.
A. Mammals are the animals that give birth to their young ones and feed them with their milk. Eg: Human being, Tiger, Cow, Kangaroo.

Answers for the Reader Exercises:

Fill in the blanks:

1. fly
2. two, six
3. beaks
4. lay
5. young ones
6. swim
7. eat
8. bellies
9. legs
10. teeth

Match the following:

1. Crawl
2. Feed young ones with milk
3. Wings
4. Amphibian

Write the names of two:

1. horse, pig
2. cockroach, butterfly
3. snake, crocodile
4. frog, toad

Science Class - III Term – 2

Ls. No. 1 Parts of Our Body

New words :

1) external parts 2) abdomen 3) trunk 4) limbs
5) skull 6) brain 7) co-ordinating 8) heart
9) rib cage 10) lungs 11) stomach 12) intestine
13) liver 14) kidneys 15) bones 16) elbow
17) wrists 18) shoulders 19) arms 20) joint
Question and Answers :

1) Name any six external parts of our body.
Ans. The six external parts of our body are
i) head ii) nose iii) waist iv) ear v) neck vi) legs

2) Name any six internal parts of our body.
Ans. The six internal parts of our body are – 1) heart 2) brain 3) lungs 4) kidneys 5) stomach 6) liver.

3] What are the functions of brain?
Ans. Brain is the control room of our body. It helps us in thinking and co-ordinating the functions of different parts of body.


4] What is the role of the kidneys? Where are they present in our body?
Ans. The kidneys help to flush out waste from our body. They are present in the abdomen on the back side.

5]W hat are joints? What do they do?
Ans. The part of the body where two bones join is known as a joint. Joints help us to move the various parts of our body.

6]How many types of limbs do we have?
Ans. We have two types of limbs, namely, upper limbs and lower limbs.

7] Describe the statements ‘all of us are different’ by giving two examples?
Ans. The statement ‘all of us are different’ is correct. Inspite of having similar body parts the colour and texture of eyes, hair and skin of different people are different. Habits and liking too differ from one another.


Diagrams : Ribcage

Ls. 2 - ORGANS AND ORGAN SYSTEMS


Question and Answers : -
1] Name the five sense organs. How do they help us?
Ans.: The five sense organs are eyes, ears, tongue, nose and skin. They help us in following ways :
1) eyes – seeing
2) ears – hearing
3) tongue – taste
4) nose – smell
5) skin – sense of touch

2] How does the brain help you in seeing things?
Ans.:
Eyes record the things around us as a picture and send it as a message to the brain.
The brain receives the message and tells us about the things that we are looking at like colour, shape, distance etc.

3] What does the skeletal system do?
Ans. :
1] Our body consists of more than 200 bones.
2] These bones form the skeletal system.
3] This system gives shape, support to the body and protect the internal organs of our body.


4] Describe the digestive system. How does it help?
Ans.
The digestive system consists of the mouth, food pipe, stomach, small intestine, large intestine and the anus.
The digestive system helps to break down the food we eat and make it useful to our body.

5] Describe the respiratory system. What does it do?
Ans. :
The respiratory system consists of the nose, the trachea and the lungs.
These organs help to breathe in fresh air and supply oxygen to all parts of the body through the blood.

6] What is the role of Circulatory system?
Ans. : The Circulatory system supplies food, oxygen and other minerals to all part of the body and takes back waste matter from various parts of the body.

Exercises : -
1. Match the following :
(a) Sight eyes
(b) Smell nose
(c) hearing ears
(d) touch skin
(e) taste tongue

New words : -
1] Sense organs
2] Trachea
3] Circulatory system
4] Nerves
5] Artery
6] Vein
7] Blood vessels
8] Heart

Ls. 3 - CARE OF OUR BODY (TERM - 2)

New words : -

1] Germs
2] Illness
3] Disinfectants

Question and Answers : -

1] Describe two good toilet habits.
Ans.
1] We should wash our hands with soap and water every time we go to the toilet.
2] We should use disinfectants to keep our toilets free from germs.

2] Describe four things you should do to take care of your health?
Ans. The four things we can do to take care of our health are :
Eat a balanced diet.
Play outdoor games / exercise well.
Drink plenty of water.
Go to bed early.

3] How can you keep the following places clean-
(1) School (2) Surroundings
Ans. ;
(1) School :
1. Do not litter the school premises with paper or food items.
2. Keep class rooms and play ground clean and tidy.

(2) Surroundings :
Do not throw / litter the streets. We should always use dustbins.
Do not spit on the roads or walls.
Do not throw plastics and other materials that may choke drains.
Do not urinate on the road side.

4] What are germs? Why should we protect ourselves from germs?
Ans. : Germs are organisms which cause many common diseases. They are very small in size. We should protect ourselves from germs as they cause diseases like cold, sore eyes, fever, cough, etc.

5] In how many ways can we keep our body healthy?
Ans. : To keep our body healthy we should :
1. Eat a balanced diet which consists of plenty of fruits and vegetables.
2. Eat at regular intervals.
3. Drink plenty of water.
4. Keep ourselves clean, tidy and free from germs.
5. Exercise and play games regularly.

6] Why should we wash our hands before we eat?
Ans.: We should wash our hands with soap and water before we take our meals to clean them off germs. This is very important as these germs are so small that we cannot see them.

True / False :

(a) False (b) False (c) True (d) False (e) True

Ls. 4. CARE OF SENSE ORGANS


New words :

Neurons
Stimulus
Infections
Contagious
Mucus
Taste buds

Questions and Answers:

1. What are sense organs?
Ans. Organs which help us to see, hear, smell, taste and feel are called sense organs.

2. What are sensory receptors?
Ans. The nerve cells or neurons are sensory receptors which pick up stimulus from the world around us and pass the information to the brain.

3. Describe some ways in which we can keep our skin healthy?
Ans. Some ways in which we can keep our skin healthy are :
1. We should take bath every day.
2. We should gently scrub our skin once a week to remove dead cells.
3. We should have a balanced diet
4. We should wear clean clothes.

4] How does exercise help to keep the skin healthy?
Ans.: Regular exercise keeps our body fit and healthy. It increases the supply of oxygen to the tissues that keep the skin healthy.

5] Describe five precautions that you should follow to take care of your ears.
Ans. The five precautions that we should take, to take care of our ears are :
1. We should not put a hard object, such as a toothpick, pencil, matchstick or a hairpin into our ears.
2. We should clean our ears regularly.
3. We should go to the doctor if we have an earache or any discharge from our ears.
4. We should clean the ears regularly with a damp cloth.


6. Describe five precautions that we should take to protect our eyes?
Ans. The following precautions to be taken to protect our eyes are:
1. We should not read while lying down.
2. We must protect our eyes from dust, smoke and poisonous gases.
3. We should take care of eye infections.
4. We should read and work only in sufficient light.
5. We should keep correct distance from the T.V. while watching it.

Objective : -

Fill in the blanks : -

(a) distance
(b) left side
(c) damp
(d) loud noises
(e) dead
(f) tight

True / False : -

(a) True
(b) True
(c) True
(d) False
(e) True


Ls. 5. CARE OF TEETH

New words : -

1. Dentine
2. enamel
3. crown
4. root
5. milk teeth
6. permanent teeth

7. Incisors
8. Canines
9. premolar

10 molar
11. Bacteria
12. Calcium



Question and Answers :-
1. What are permanent teeth?
Ans. The new set of teeth that come in place of milk teeth are called permanent teeth.

2. What are milk teeth?
Ans. The first set of teeth which appear when a child is six or seven months old are called milk teeth.

3) What are the three types of teeth? What are their functions?
A) The three types of teeth and their functions are :
i) Biting teeth (incisors)- They are used to bite food.
ii) Tearing teeth (canines)- They are used to tear off pieces of food.
iii) Grinding teeth (pre molars and molars) - They are used to chew/grind the food.

4) Why is brushing our teeth twice a day essential?
A) Brushing teeth twice a day is essential as food particles get stuck up between the teeth and start to decay if they are not removed. Germs can breed in these food particles creating a foul smell in the mouth and eventually causing tooth decay.

Diagrams : Structure of a tooth.


Ls. 6 - Food

New Words :
Cells, Tissues, Nutrients, Carbohydrate, fat, protein, vitamins, minerals, pulses, resistance, roughage, bowel-movement, temperature, Raw food, detoxifies, chronic.

Questions and answers :
1) Why do we need food?
A) We need food because :
i) It provides us with the energy to work and play.
ii) It helps to repair damaged cells and tissues.
iii) It helps to keep the body healthy.

2) Milk is a complete food. Explain.
A) Milk is a complete food as it contains all the nutrients, namely carbohydrates, fats, proteins, vitamins and minerals. Milk helps to protect our body, provides resistance against diseases and also helps to heal injuries.

3) What is roughage?
A) Roughage is the part of food that cannot be digested. It helps the digestive system to work properly and helps to remove waste from the body.

4) Explain why ‘Cooking is essential’?
A) Cooking is essential because it destroys harmful germs present in the raw food and gives taste and flavour to the food. It is easy to digest cooked food. Eating cooked food helps to increase the count of white blood cells in the body. These cells help to fight against diseases.

5) What are the advantages of eating raw food?
A) The advantages of eating raw food are :
i) Raw foods contain a lot of nutrients and proteins.
ii) The enzymes present in raw foods help in digestion.
iii) The chlorophyll present in raw food detoxifies our body.
iv) It protects us from chronic and acute diseases.

* * *


TERM – III
Class: III Sub: Science
Lesson – 1. WHAT ARE THINGS MADE OF ?

New Words:-
1. matter 3. visible 5. object
2. occupies 4. invisible 6. space

Question and answers:-
Q1. Define matter.
Ans. Any object that occupies space and has weight is called matter.

New Words:-
7. breakable 9. opaque 11. crushed
8. transparent 10. conductors 12. magazines

Question and answers:-
Q2. Define the following: -
a) opaque objects b) transparent object
a) Opaque: - Objects which do not allow light to pass through them are called opaque objects. Eg: wood, stone

b) Transparent objects: - Objects which allow light to pass through them are called transparent objects.
Eg: glass

Q3. What do we make paper from? Give two uses of paper.
Ans. We make paper from wood pulp. Wood pulp is made from small pieces of crushed wood.
Uses: - 1. Paper is used in making newspapers, magazines, card board, books etc.
2. Paper is also used for making packing boxes.

Q4. What do we make from the skin of animals? Give its uses.
Ans. We make leather from the skin of animals. Leather is used for making shoes, bags, clothes etc.

Q5. What are conductors? Give three examples.
Ans. Conductors are the objects which allow heat or electricity to pass through them.
Ex: copper wire, iron rod, aluminium vessel, silver plate.

Q6. What are non-conductors? Give three examples.
Ans. Non-conductors are the objects which do not allow heat or electricity to pass through them.
Ex: glass, plastic, wood.



Lesson – 2. MATTER

New words:
1. matter 3. occupies 5. molecules
2. universe 4. particles

Question and answers:-
Q1. What is matter?
Ans. Anything that has mass and occupies space is called matter.
New words:
1. solid 3. liquid 5. definite 7. container 9. mixture
2. gas 4. properties 6. packed 8. arrangement 10. volume

Question and answers:-
Q2. Name the three states of matter.
Ans. The three states of matter are: -
Solids, liquids and gases.

Q3. Describe two important properties of solids, liquids and gases.
Ans. Solids: - 1. In solids, molecules are firmly packed.
2. They occupy a definite shape and have weight.
Ex: pen, pencil, book.
Liquids: - 1. In liquids, molecules are loosely packed.
2. That is why they flow and take the shape of the container they are in.
Gases: - 1. In gases, molecules are very loosely and freely packed.
2. They also do not have a definite shape and volume.

New words:
1. exist 3. heated 5. evaporates 7. escapes
2. freezer 4. cooled 6. water vapour
Question and answers:-
Q1. Name the uses of any two solids, liquids and gases.
Ans. Uses of solids: -
1. Solids are hard and strong. So, we use bricks, wood, steel, glass etc. to build houses, The food we eat is also solid.

Uses of liquids: -
1. We drink milk to be strong and healthy.
2. We use water for drinking, bathing and washing.
3. Petrol, kerosene and diesel are used as fuels.

Uses of gases: -
1. We breathe in oxygen that is present in the air.
2. We use gas as a fuel in the kitchen.
3. Plants use Carbondioxide present in the air to make food.


New words: -
1. solute 3. solution 5. insoluble 7. universal solvent
2. solvent 4. soluble 6. substances 8. dissolve
9. disappear

Question and answers:-
Q5. What is a solution?
Ans. A solute and a solvent together make a solution.
i.e. solute + solvent----> solution
Eg: sugar + water ---->sugar water

Q6. What is a solvent? Give example.
Ans. The substance in which the solute dissolves is known as a solvent.
Ex: water dissolves sugar. Water is a solvent.

Q7. Give an example to show how the state of a substance can change.
Ans. The state of matter can be changed in different ways.
Ex: We can change water from one state to another.
1. When water is kept in a freezer it changes into ice. (liquid solid)
2. When ice is heated it turns to water. (solid liquid)
3. When water is heated it changes to water vapour. (Liquid gas)
4. When watervapour is cooled it becomes water again. (gas liquid)

Question and answers:-
Q8. Name some substances that do not dissolve in water.
Ans. Soil, wood, iron, etc. are the substances that do not dissolve in water.

Diagram : Arrangement of molecular in solids, liquids and gases.
* * *


Lesson – 3. Weather and Seasons
New words: -
1. weather 3. conditions 5. directly 7. lighting 9. breeze
2. atmosphere 4. factors 6. unpleasant 8. thunder

Answer the following questions:-
Q1. What is weather?
Ans. The conditions of the atmosphere in a place, on a particular time, is called weather.

Q2. Name four factors that influence weather.
Ans. The four factors that influence weather are:
Sun, clouds, wind and rain.

New words: -
1. climate 5. winter 9. temperature 13. stockings
2. season 6. conditioners 10. beverages 14. splashed
3. summer 7. puddles 11. misty
4. rainy 8. monsoon 12. mildly

Answer the following questions:-
Q3. Name the main seasons of India.
Ans. The main seasons of India are winter, summer and rainy seasons.

Q4. Which seasons do you like the most? Why?
Ans. The season I like the most is ________________________
(free response)

New words: -
1. delay 4. scientific 7. pressure
2. forecast 5. meteorology 8. instruments
3. information 6. direction 9. atmospheric pressure

Answer the following question:-
Q5. Describe how the weather affects our daily lives.
Ans. The way by which our daily lives get affected due to weather are : -
1. We try to stay indoors when it is raining. Heavy rains may even cause floods.
2. Driving in stormy weather is not safe.
3. During storms the sea becomes rough and ships cannot sail smoothly.
Fishermen are advised not to go out on the sea when there is a storm.
4. Flights and trains get delayed due to foggy, stormy and rainy weather
conditions.
5. Sudden changes in the weather may also make us fall ill causing illnesses like
fever, cough, cold etc.

Q6. What is water cycle?
Ans. The continuous and repeated change of water into water vapour and again to water is called water cycle.

B. True of False.
1. False
2. True
3. False
4. False
5. False

Matching
2, 4, 1, 5, 3.

Diagram : Water cycle.

Lesson – 4. The Sun, Moon and Stars


New words: -
1. universe 5. Ursa Major
2. constellation 6. direction
3. cloudless 7. Orion
4. Saptarishi 8. twinkling

Answer the following questions:- Apart from the textbook questions
Q1. What are constellations?
Ans. A group of stars that form a definite pattern / picture is called constellation.

Q2. Why do stars look small?
Ans. Stars look small because they are very far away from the earth.

New words: -
9. brightest 13. solar system
10. energy 14. planets
11. reflected 15. survive
12. surfaces
Answer the following question:-
Q3. What is the solar system?
Ans. The sun, the planets and their moons make up the solar system.

New words: -
16. rotation 19. appears
17. revolution 20. roughly
18. movement

Answer the following question:-
Q4. How are days and nights formed?
Ans. The Earth spins on its own axis and this movement is called rotation of the Earth. It takes 24 hours for the earth to complete one rotation. The rotation of the earth causes days and nights.

Q5. Define the words.
a) Rotation b) Revolution
Ans: a) Rotation: - The movement of the earth on its own axis is called
rotation. Rotation of the earth causes days and nights.
b) Revolution: - The movement of the earth around the sun in a fixed orbit is
called revolution. Revolution of the earth causes seasons.

New words: -
21. satellite 24. Crescent moon
22. phases 25. lunar eclipse
13. new moon

Answer the following question:-
Q6. Name the Earths’ natural satellite.
Ans. The moon is the only natural satellite of the earth.

Answers to fill ups.
1. huge star
2. heat, light and energy.
3. sun
4. earth
5. light

Matching
1. ( 2 )
2. ( 3 )
3. ( 1 )
4. ( 4 )
5. ( 5 )

Diagram : Phases of Moon.

Lesson – 5. Protecting Our Environment

New words: -
1. garbage 6. dispose
2. environment 7. recycling
3. protecting 8. materials
4. terrible 9. chemically
5. municipal corporation 10. surroundings

Answer the following question:-
Q1. Why should we protect our environment?
Ans. We should protect our environment in order to
1. Protect ourselves from various diseases.
2. To save natural resources.
3. To keep environment free from pollution.

Q2. Why should we keep dustbins covered?
Ans. Germs breed in dustbins. If we keep the dustbins covered, these germs will not spread and cause diseases. So, we should always keep dustbins covered.

Q3. Why should we plant more trees?
Ans. We should plant more trees because,
1) They help in keeping environment clean
2) They release oxygen into the air.
3) We should not cut down trees to make roads, buildings and factories.
But we must replant trees to save our environment.

Q4. What is waste segregation?
Ans. The separation of the biodegradable and non-biodegradable waste in our garbage is called waste segregation.

Q5. Define the terms
a) Biodegradable b) Non-biodegradable
a) Biodegradable: - Waste materials that decompose naturally are called biodegradable waste.
Ex: Vegetable and fruit peels.
b) Non-biodegradable: - Waste materials that cannot decompose naturally are
called non-biodegradable wastes.
Ex: Tins, plastic bags, cane, bottles.

New words: -
11. segregation 16. unleaded 21. atmosphere
12. biodegradable 17. environment 22. polluted
13. non- biodegradable 18. continuously 23. emission
14. decompose 19. materials 24. plastic
15. compressed natural gas 20. garbage 25. naturally

Answer the following question:-
Q6. Why should we reduce the use of plastic bags?
Ans. We should reduce the use of plastic bags because
1. They do not decompose naturally.
2. It is a threat to our surroundings.
3. Animals like cows often fall sick because they eat plastic bags along with
their food.
4. We should try to use cloth bags or paper bags.

Fill in the blanks.
1. non-biodegradable waste 2. eco-friendly fuels
3. biodegradable waste 4. biodegradable waste
5. smoke
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