class 4 general science notes unit:2 the animal world

Class 4 – General Science Notes

UNIT:2 – THE ANIMAL WORLD

Q1. Fill in the blanks.

i. Animals need water, energy and oxygen to survive.

ii. Energy helps repair damageto the body.

iii. A food chain is the path by which energy passes from one living thing to

another.

iv. Carnivoresare animals that only eat meat.

v. A frog goes through five stages in its life cycle.

Q2. Answer these questions.

i. Why is energy important for animal’s survival?

Ans. Animals need energy to carry out all the body processes required to

maintain life. Without energy, an animal is unable to move, to digest its

food, to reproduce, to grow or even to breathe.

ii. Why are green plants called producers?

Ans. Green plants are called producers because they produce their own food by

the process of photosynthesis.

iii. Why is animal reproduction important?

Ans. Reproduction is important for animals because of the following reasons:

a) It helps to maintain the number of individuals of a species.

b) It helps in the survival of the species and prevents their extinction.

c) If living things did not have the ability to reproduce, there would be no

living things on Earth.

iv What is adaptation?

Ans. Adaptation:

Adaptation refers to change in structure, function or behaviour by which a specie

or an individual improves its chances of survival in a specific environment.

v. Write names of different parts of the food chain.

Ans. The names of different parts of the food chain are:

i. Producer

ii. Primary consumer

iii. Secondary consumer

iv. Tertiary consumer

vi. What is meant by metamorphosis?

Ans. Metamorphosis is a process by which an animal changes its appearance and

Body structure during the different stages of its life cycle.

WORKBOOK PAGES (6,7,8)

UNIT: 6 – MATTER AND MATERIALS

Q1. Fill in the blanks.

i. Solids, liquids and gases are three states of matter.

ii. Particles in a solid are packed tightly together and can’t move.

iii. A liquid can flow and take up the shape ofa container.

iv. The molecular formula for the water is H2O.

v. A mixture is a combination of two or more different materials.

Q2. Answer these questions.

i. What is the difference between an atom and a molecule?

Ans. Atom:

Atoms are tiny particles. All matter is made up of atoms.

Molecule:

A molecule is a particle made up of two or more atoms.

ii. Draw three diagrams showing how particles are packed within.

i. a solid

ii. a liquid

iii. a gas

Ans:

iii. Differentiate between a solution and a suspension.

Ans. Solution:

A solution is a mixture in which the solid material dissolves in the

liquid. They do not separate from each other if they are left to stand.

Suspension:

A suspension is a mixture in which the materials separate from

each other if they are left to stand.

iv. How can matter be change from one state to another?

Ans. Matter can change from one state to another if heated or cooled.

If ice (a solid) is heated, it changes to water (a liquid). If water is heated, it

changes to steam (a gas). On the other hand, when this steam cools down, it

changes to liquid and when this liquid cool, it changes to solid. The particles

of ice, water, and steam are identical, but arranged differently.

WORKBOOK PAGES (24,25)

UNIT: 10 – THE SOLAR SYSTEM

Q1. Fill in the blanks.

i. The shape of the Earth is called a sphere.

ii. Each of the planets rotates or spins on its own axis.

iii. The Earth is a planet.

iv. Most of nebulae contain a lot of hydrogen gas in them.

v. Earth and our solar system exist in a galaxy known as Milky Way.

Q2. Answer these questions.

i. What is the axis of the Earth?

Ans. The axis is an imaginary line passing through the North and

South Poles. The Earth is constantly spinning on its axis.

ii. How long does it take the Earth to orbit the Sun?

Ans. The Earth takes 365 days, 48 minutes, and 46 seconds to orbit the Sun.

iii. What is space?

Ans. Space is the area in which planets, stars, moons, and other heavenly

bodies exist.

iv. How many planets are there in our solar system? Name them.

Ans. There are eight planets in our solar system. Their names are:

i. Mercury

ii. Venus

iii. Earth

iv. Mars

v. Jupiter

vi. Saturn

vii. Uranus

viii. Neptune

WORKBOOK PAGE (38)

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