CBSE Class 4 Science Revision Worksheet

1 Answer the following questions:-

Q1 Why is fog dangerous?

Ans________________________

Q2 How can you save water? Write 3 points.

Ans________________

Q3 List four factors affecting rate of evaporation.

Ans (a)________________________ (b)____________________________________

(c)_________________________ (d) ____________________________________

Q4 Write two ways how you can conserve energy at home.

Q5 How can you keep your house ventilated?

Hard words
1. Accident
2. Injury
3. Electrical appliances
4. Bleeding
5. Fracture
6. First Aid
7. Bandage
8. Ambulance

Multiple choice questions.

Q1. A first Aid box must contain
a. A roll of cotton b. Dettol or antiseptic lotion
d. bandage c. All of these
Answer : All of these

Q2. Tick the incorrect statement
a. Always walk on footpath
b. Walk closer to the animals like donkey, horse etc
c. Cross the road only at zebra crossing
Answer : Walk closer to the animals like donkey, horse etc

Fill in the blanks
1. Never wear clothes made of___ when you are in kitchen
Answer : synthetic

2. We should walk on the___________
Answer : left side of the road

3. Never play with ________ objects.
Answer : sharp

4. Never go alone for _________.
Answer : swimming

Put (√) or (×) in the circles given below keeping safety rules in your mind
1. Using knife (√)
2. Using sharpener (×)
3. Playing with sharp tools (√)
4. Playing on the road (√)
5. Flying kite on the terrace (√)

Question answer

Q1. What is first aid?
Answer : The first help give to an injured person before reaching the doctor is called first aid .

Q2. What is the importance of first aid?
Answer : First aid is important during emergency
1. To save life
2. To prevent the condition from worsening
3. To speed up the recovery

Q3. How can we avoid accidents at home?
Answer : We can avoid accident at home in following ways
1. Do not rush up down the stairs
2. Keep your floors clean and dry
3. Put your toys and bags in their proper place
4. Do not wear synthetic clothes in the kitchen

Q4. How will you help a person who has fainted?
Answer : If the person has fainted, rest his or head lower than his or her body. This helps to increase the supply of blood to the brain

Answer in one word
1. Happening by chance
Answer : Accident

2. Physical damage or harm to human body
Answer : Injury

3. Breaking of bones
Answer : Fracture

4. A strip of clothes mostly use to cover the wounds
Answer : Bandage

5. A vehicle use to carry the sick or injured to the hospital
Answer : Ambulance

Jumble words
1. TCOOTN
Answer :Cotton

2. SSSSICOR
Answer :Scissors

3. GEAANDB
Answer : Bandage

Activity
Make your own first aid box at home and keep the things required for the first aid

Leaf-the food factory of plant

A. Hard words
Structure, leafapex xylem, phloem ,chlorophyll stomata ,photosynthesis ,glucose starch , microscope

B. Define

1.Photosynthesis:- Photosynthesis is the process by which plants make their own food using carbon dioxide, water , Chlorophyll and sunlight.
2.Stomata- small opening on the under surface of leaf which help in exchange of gases.
3.Midrib –The central thick part of the leaf.

C. Name the following
1. Green substance in the leaf                                          = Chlorophyll
2.Gas needed to make food in green plants                       = Carbon dioxide
3.Gas released by green plants during photosynthesis        = Oxygen
4.Small pores that help the leaf in exchange of gases         = Stomata
5.Food formed as a result of photosynthesis.                     = Glucose
6.Animals depend on plants for                                        = oxygen and food
7.Tubes that carry water up to the                                   = Xylem
8.An instrument that makes tiny objects look bigger         = microscope

Answer the following questions

Question.What is photosynthesis?
Answer : The process of making food by green leaves of plants in the presence of sunlight with the help of carbon dioxide nutrients and water is known as photosynthesis.

Question. Give two examples of unusual plants.
Answer : Mushroom and cactus

Question. Why are leaves green?
Answer :The leaves are green because they contain a green substance called chlorophyll.

I. Give one word answer:

1. Tiny organism that can only be seen through a microscope. ____

2. Harmful microbes. _______

3. Fungi that help in making bread. ________

4. Removal of water from any substance. ________

5. An unfortunate, unexpected and unintentional incident. __________

6. The discolouration of skin caused by pressure. __________

II. Fill in the blanks:

1. Dysentry is caused by _____.

2. _____ are plant –like organism that lack chlorophyll.

3. Viruses are always _____________ to us.

4. Wash your hands before and after _____.

5. Medicines should be kept in ______ bottles.

6. Always cross the road at __________

7. The _________ can be used to extinguish electric fire.

III. State TRUE or FALSE:

1. Young children can play with knives.

2. We should follow safety rules at all times.

3. Accidents happen due to carelessness.

4. We should throw things on others.

5. Microbes grow faster in warm and damp places.

6. Protozoa are single celled animals.

IV. Answer the following:

1. Define an accident.
____________________________________________________
 

2. What is first aid?
____________________________________________________
 

3. Why is milk boiled before use?
____________________________________________________
 

4. What first aid should be given to a person having bruise in his hands?
____________________________________________________
 

5. Write three ways to protect ourselves from harmful microbes.
____________________________________________________
 

6. Name four types of microbes and write two diseases for each.
___________________________________________________
 

I. Fill in the blanks:-

1. Three quarter of the Earths area is covered with ___________.

2. The _________ are named after the sundri tree.

II. Guess ……..Who am I ????

1. I am called the mini zoo of the world.

2. I grow on rocky shores or underwater close to the coast.

III. Give two examples of:-

1. Insectivorous plants

2. Scavengers

IV. Rewrite the following correctly:-

1. A shark is a mammal which lives in water.

2. Almond trees grow in desert regions.

V. Define the following terms:-

1. Carnivores

2. Terrestrial plants

3. Parasites

VI. Give Reasons:-

1. Vultures are becoming extinct.

2. Desert plants have small leaves.

3. Trees that grow in marshy areas grow breathing roots.

VII. Answer the following:-

1. How do fishes adapt themselves to live in water?

2. How do fixed plants grow in water?

3. Write any two uses of acacia plant.

FILL IN THE BLANKS:

1. ____________ is a non green plant.

2. The place where an organism lives is called its ________.

3. The remaining food prepared by the plants is stored in the form of ________.

4. The flat part of the leaf is called _________.

5. Egg cluster of frog is called _______.

6. ____ protects and provides water to embryo.

7. ________, __________, _________ are few examples for a group of animals called reptiles.

8. The development of animals from the embryo stage to the adult is their __________.

9. ________ cannot be digested but helps in getting rid of undigested food.

10. The region between the crown and root is called _____.

11. ______ is the largest organ in our body.

12. Bile is secreted by ______.

13. ________ breaks down the starch into simpler substances.

14. Complete the table below

Q1 –Draw a tree and draw /paste pictures of 2 arboreal animals. In the space on

the right side of the box, write the characteristics which help them to climb trees.

Q2 Name them.

a) 2 aerial animals …………………….. , ……………..

b) 2 Scavengers ……………………….. , ………………………..

c) 1 migratory bird ………………….. , …………………..

d) 2 animals that show aestivation ……………….. , ……………..

f) 2 cold blooded animals. …………….. , ………………..

Q 1 .Why do trees growing on mountains have needle like leaves?

Q2 Draw a stomata and write its functions.

Q3 Match the following.

                   A                                                                B

1. Food factory of plant                                      1. Leaf blade

2. Extra food stored as                                      2. Leaf

3. Gas required during photosynthesis             3. Starch

4. Flat surface of leaf                                        4. Carbon dioxide.

5. Root hair                                                       5. Chlorophyll

6. Green pigment in a leaf                                6.Helps to absorb water from soil

Q1. Fill in the blanks

(1) A push or a pull acting on an object is called________

(2) ____________ is the ability to do work .

(3) We get solar energy in the from of ________ and _____________.

(4) __________ force keeps us on the ground .

(5) ________________ force stops the moving object.

(6) The anis of rotation on which earth turns is _______

(7) _______ is called as mail air.

(8) __________ is a simple machine made up of wheel and a rope.

Q.2 Choose the correct answer from colume “B” and write answer in column “C”
Column A                       Column B                                 Column C
Lever                    Solar Energy                         ____________________
Sun                       Side closer to the sun           ____________________
Summer                used for moving heavy
                             objects with losseffort           ____________________
Screw                   Sun light heats up the 
                             air during this time                _____________________
Day                      used for holding objects
                            together .                              _____________________

Q.3 Give one words for the following     

(1) A gentle wind________________

(2) Energy obtained froms water _______

(3) A storm that occurs with thunder __________________

(4) Enerty obtained from urind __________________

Q.4 Define the following terms

(1) friction ____________________________________________

(2) Gravity ____________________________________________

(3) Storm ____________________________________________

(4) Simple machine

Q.5 Answer the following question -

i) What are the uses of simple machines ?
_________________________________________________________
 

ii) How are seasons formed ?
________________________________________________________
 

iii) What are dams ? Write their uses.
_________________________________________________________
 

iv) State the four ways by which the Sun causes changesa in the weather around us.
_________________________________________________________
 

V) List the four uses of force ?
________________________________________________________
 

vi) Sea breeze blows during the day. Give reasons.
_________________________________________________________
 

vii) State the usesa of -

a) Inclined Plane - _________________________________________

b) Wind Energy - _________________________________________
 

c) Wheel and axle - _________________________________________
 

Q.5 Differentiate between

i) Evaporation Condensation
_________________________________________________________
 

ii) Sea Breeze Land Breeze
_________________________________________________________
 

Q.6 Draw a digram of the Earth showing formation of day and night.

A- Give one word answer:---

1. The process of breaking down of food into simpler form. ____

2. A vegetable eaten raw. ____

3. A food item rich in starch . ______

4. A digestive liquid secreted by salivary glands. _________

5. The diet which contains all the nutrients in the right amount. ______

Answer : 1.Digestion 2- Carrot 3-rice 4- Saliva 5-Balanced diet

B- Fill in the blanks:---

1- The undigested food passes into the intestine _________.

2- _______ is the fibre present in our food.

3- ____ and ______ pour their digestive juices into small into small intestine.

4- ________ is a way of preserving food.

5- Food rich in ________ and __________ keep us fit and healthy.

6- ____________ gives us more energy than carbohydrates.

7- In the stomach ____________ are broken into a simpler form .

8- Cooking makes food __________, tasty and easily _________.

9- ____________ and _____________ are ways of cooking food.

10- Our stomach is a hollow, _____________ bag.

Answer : 1. Large intestine 2- Roughage. 3-Liver , pancreas 4- Freezing 5- vitamins ,minerals 6- Fats 7- proteins 8-soft , digestible 9- Boiling, steaming

C- Answer the following questions:-----------

1- Name three organs of your digestive system which make digestive juices.
Answer : A) Mouth, stomach ,small intestine .

2- Name three subtances that can be added to food to preserve it .
Answer : B) Sugar, syrup,salt and vinegar can be added.

D- Write the functions of the given parts of the digestive system:----

1- Mouth-_______________

2- Stomach-_____________

3- Small intestine-__________

4- Large intestine-_____________

Answer : a) Mouth - The process of digestion begins.
b) Stomach - The food is churned here.
c) small intestine – Absorbs the digested food and carry it to a all body parts
d) large intestine - The undigested food passes into it.

E- Match the following:-
Column A                                     Column B
1- Mouth                           a- undigested food passes into it
2- Large intestine             b- break food in pieces
3- Liver                             c- produce juices in mouth
4- Stomach                      d- digestion begins
5- Teeth                            e- absorb the digested food
6- Small intestine             f- churned food
7- Salivary glands           g- pour the juices in small intestine

Answer : 1-d. 2-a. 3-g. 4-f. 5-b. 6-e. 7-.c

Q1 Fill in the blanks using the correct words-

1. ------------------- is necessary to hatch the eggs. (warmth/water)

2. The----------- part of egg is rich in vitamins and minerals. (albumen/ yolk)

3. The baby bird is called the-------------. (chick/cub)

4. The series of changes after which a larva changes into an adult is known as ---------.(reproduction/metamorphosis)

5. Dolphins and whales breathe through their-----------. (skin/lungs)

Q2 Give one word for the following.

1. Yellow part of the egg. --------------

2. Animals that have hair --------------

3. White jelly-like part of egg. ----------------

4. Larva of a frog. -----------------

5. Shedding of old skin by an insect. ------------

6. Stage in the life cycle of a butterfly that ------------- changes into an adult.

7. The stage in the life cycle of insects ---------------- When they come out of an egg.

1- Fill in the blanks:--

a- The sharp and pointed teeth in our mouth are called __________.

b- A person who is 30 years old should have 32 __________ teeth.

c- In our mouth the 4 teeth at the front of each jaw are _______,called the cutting teeth.

d- A tooth with a cavity will start paining if the cavity reaches the _____.

Answer : a-canines, b-permanent, c-incisors, d-pulp,

2-Match the following:----

Column A          Column B

1- Incisors         a- tearing teeth

2- Canines         b- hardest substance

3- Premolars      c- virus

4- Molars           d- cutting teeth

5- Enamel          e- cracking teeth

6- Microbes        f- grinding teeth

Answer : 1- cutting teeth, 2- tearing teeth, 3- cracking teeth, 4- grinding teeth, 5- hardest substance, 6- virus.

3-Write true or false:----------

a- Humans have 32 milk teeth.

b- All our teeth have the same shape.

c- The surface of our teeth is harder than a bone.

d- Premolars and molars crush and grind food.

e- A microbe is as small as a grain of sand.

f- All microbes are harmful to us.

g- We use dental floss to clean between two teeth.

Answer : a- FALSE, b- FALSE, c- TRUE, d- TRUE, e- FALSE, f- FALSE. g- TRUE

1 Answer the following questions:-

Question Q1. Why is fog dangerous?
Answer: Fog is dangerous because it reduces visibility on roads, making it difficult for drivers to see other vehicles, pedestrians, and traffic signals, which frequently leads to road accidents.
In simple words: Fog acts like a thick cloud near the ground that blocks clear vision and causes accidents.

Exam Tip: Mention reduced visibility and traffic accidents as key points to secure full marks.

Question Q2. How can you save water? Write 3 points.
Answer: 1. Turn off the tap while brushing your teeth or soaping hands.
2. Fix leaking taps and pipes immediately.
3. Use a bucket of water to bathe instead of using a shower or running hose pipe.
In simple words: Save water by turning off taps when not in use, fixing leaks, and using buckets instead of hoses.

Exam Tip: Always list distinct, practical habits like turning off taps and fixing leaks.

Question Q3. List four factors affecting rate of evaporation.
Answer: (a) Temperature
(b) Wind speed
(c) Humidity (amount of moisture in the air)
(d) Surface area of the liquid
In simple words: Evaporation happens faster when it is hot, windy, dry, and when the liquid is spread over a large area.

Exam Tip: Memorize the four core environmental factors: temperature, wind, humidity, and surface area.

Question Q4. Write two ways how you can conserve energy at home.
Answer: 1. Switch off lights, fans, and electrical appliances when leaving a room.
2. Use energy-efficient LED bulbs and appliances instead of traditional incandescent bulbs.
In simple words: Save electricity by turning off unused switches and using energy-saving bulbs.

Exam Tip: Focus on everyday actions like switching off lights and using LED bulbs.

Question Q5. How can you keep your house ventilated?
Answer: We can keep our house ventilated by keeping windows and doors open to allow fresh air and sunlight to enter, and by installing exhaust fans in kitchens and bathrooms to remove stale air and odors.
In simple words: Open windows and use exhaust fans to let fresh air in and bad air out.

Exam Tip: Mention both natural ventilation (doors/windows) and mechanical ventilation (exhaust fans).

Question Q6. Why should we throw biodegradable and non-biodegradable waste separately in two dustbins?
Answer: We should throw them separately because biodegradable waste (like vegetable peels) can be easily decomposed to make compost, whereas non-biodegradable waste (like plastics) does not rot and needs to be sent for recycling. Mixing them makes waste management and recycling difficult.
In simple words: Separating waste helps in making compost from organic waste and recycling plastic and metal easily.

Exam Tip: Highlight 'composting' for biodegradable waste and 'recycling' for non-biodegradable waste.

Question Q7. Give two examples each of waste that can be recycled, reduced and reused.
Answer: 1. Recycled: Old newspapers and empty plastic bottles.
2. Reduced: Wastage of food and unnecessary use of plastic bags.
3. Reused: Glass jars for storing kitchen items and old clothes turned into cleaning rags.
In simple words: Give examples of things we process again (recycle), use less of (reduce), or use again in a different way (reuse).

Question Q8. What is energy?
Answer: Energy is defined as the capacity or ability to do work. It exists in various forms such as heat, light, electrical, and mechanical energy.
In simple words: Energy is the power that makes things work or move.

Exam Tip: Use the standard scientific definition: "capacity to do work".

Question Q9. Write three advantages and three disadvantages of renewable energy.
Answer: Advantages:
1. It is clean and produces little to no greenhouse gases or pollution.
2. It is inexhaustible and will never run out (e.g., solar, wind energy).
3. It helps lower electricity bills and reduces dependence on fossil fuels.
Disadvantages:
1. It is weather-dependent (e.g., solar panels need sunlight, wind turbines need wind).
2. Initial setup and installation costs for renewable systems are very high.
3. Energy storage and backup systems (like batteries) can be expensive and complex.
In simple words: Renewable energy is clean and endless, but it depends on weather and costs a lot to set up initially.

Exam Tip: Group your points clearly under 'Advantages' and 'Disadvantages' subheadings.

2 Colour the biodegradable substances in green and non-biodegradable substances in red.

Question 2. (a) Fruit and vegetable peels
Answer: Biodegradable substance (Colour: Green)
In simple words: Plant waste rots naturally.

Exam Tip: Plant and animal waste are always biodegradable.

Question 2. (b) Plastic bags
Answer: Non-biodegradable substance (Colour: Red)
In simple words: Plastic does not decay naturally.

Exam Tip: Plastics, glass, and metals are non-biodegradable.

Question 2. (c) Tin can
Answer: Non-biodegradable substance (Colour: Red)
In simple words: Metal cans stay in soil for hundreds of years.

Exam Tip: Metals do not decompose easily.

Question 2. (d) Cotton shirt
Answer: Biodegradable substance (Colour: Green)
In simple words: Cotton comes from plants and rots over time.

Exam Tip: Natural fibers like cotton and wool are biodegradable.

Question 2. (e) Newspaper
Answer: Biodegradable substance (Colour: Green)
In simple words: Paper is made from wood pulp, so it decomposes.

Exam Tip: Paper products are biodegradable.

Question 2. (f) Fallen leaves
Answer: Biodegradable substance (Colour: Green)
In simple words: Leaves rot and mix back into the soil.

Exam Tip: Organic garden waste is biodegradable.

Question 2. (g) Glass bottle
Answer: Non-biodegradable substance (Colour: Red)
In simple words: Glass does not break down in nature.

Exam Tip: Glass is completely non-biodegradable.

Question 3. Match the following:-
1 Air is a - (d) mixture of gases
2 Water changes into steam - (f) when it is heated
3 Polluted water is - (e) harmful to drink
4 Oxygen is required for - (a) breathing and burning
5 Water droplets on cold bottle - (c) condensation
6 Burning of fuel - (b) cause air pollution
Answer: 1 - (d), 2 - (f), 3 - (e), 4 - (a), 5 - (c), 6 - (b)
In simple words: Correctly paired environmental and scientific terms.

Exam Tip: Read both columns carefully before matching.

Question 4. You have been elected the mayor of your city. What will you do to bring down the level of air pollution in your city?
Answer: As mayor, I would take the following steps:
1. Promote public transport and encourage the use of electric vehicles.
2. Ban the burning of garbage, leaves, and crop residue.
3. Plant more trees along roadsides and in parks to absorb pollutants.
4. Set strict emission rules for factories and industrial plants.
In simple words: Reduce smoke by planting trees, using electric transport, and stopping garbage burning.

Exam Tip: Mention practical civic measures like public transport, tree plantation, and curbing factory emissions.

Question 5. Find out what 'Earth Hour' is and why it is organized. Write a few lines on it.
Answer: Earth Hour is a global environmental movement organized by the World Wide Fund for Nature (WWF). During Earth Hour, individuals, communities, and businesses turn off non-essential electric lights for one hour, usually on the last Saturday of March. It is organized to raise awareness about climate change, energy conservation, and the importance of protecting our planet.
In simple words: Earth Hour is when people turn off lights for one hour to show care for the Earth and save energy.

Exam Tip: Remember the core purpose: raising awareness for energy conservation and climate change.

Question 6. There are other places where you can find rainbow-like coloured patterns. Find out any such place/situation.
Answer: Rainbow-like colored patterns can be seen in several places:
1. In the soap bubbles when exposed to sunlight.
2. In a thin layer of oil floating on water puddles on a wet road.
3. Through water sprinklers or garden water hoses on a sunny day.
4. Using a prism or a glass CD reflecting light.
In simple words: We see rainbow colors in soap bubbles, oil films on water, and water sprays in sunlight.

Exam Tip: Soap bubbles and oil slicks are the easiest everyday examples to cite.

Question 8. Hydrogen is the lightest gas in the air. Do you know which one is the second lightest gas. Colour all the 'H' boxes in the grid given below. Which gas did you find?
Answer: Helium
In simple words: The second lightest gas after hydrogen is helium.

Exam Tip: Helium is widely known as the second lightest and noble gas used in balloons.