Maharashtra Board Class 4 EVS Chapter 1 The Life Cycle of Animals PDF Download

The Life Cycle Of Animals

Look at the puppies and their mother in the picture. Do you see some similarities?

Look at the butterfly and the caterpillar that has come out of the egg. Do you see any similarities?

A hen lays eggs. Chicks come out of those eggs.

Do kittens come out of eggs?

A kid and a fully grown goat are not very different to look at. There is not much difference between a kitten and an adult cat. These babies grow in their mother's tummy and are born from the mother's tummy too. These animals do not lay eggs.

But some animals like crows, spiders, lizards lay eggs.

Teacher's Note

Many animals in India like hens and snakes lay eggs. But dogs and cats do not lay eggs. You can see this in villages and at home.

Exam Trick

Remember: Eggs = lay eggs. No eggs = baby inside mother's body. This is the main difference to remember.

Points to Remember

Some animals lay eggs and some do not lay eggs.
Puppies grow inside their mother's body.
Chicks come out of hen's eggs.
Kittens come out of their mother's body, not from eggs.

The Growth Of Animals

A chicken is born from an egg.

Ants, butterflies, fish, frogs, snakes are all animals that lay eggs. But, we do not often see their eggs. The eggs of some very small animals are very tiny. We would hardly notice them. So, we do not come to know that these animals lay eggs. But, we know for sure that a hen lays eggs. Her eggs are big enough to be easily seen.

A hen lays eggs. Warmth is necessary for the chicks to grow inside the egg. So, after laying them, the hen sits on the eggs to keep them warm. The chicks inside slowly keep growing.

When its growth is complete, the chick breaks the eggshell and comes out.

The hen looks after its chicks till they grow a little bigger.

When a hen is hatching her eggs, she becomes aggressive for fear of their safety. She attacks anyone who tries to go near the eggs.

A new term: hatch - When a hen sits on her eggs to warm them, she is said to be 'hatching' her eggs.

Teacher's Note

In Indian villages, many people keep hens at home. You can see a hen sitting on eggs for many days. This is called hatching.

Exam Trick

Remember: Hatch = sit on eggs. Warm = important for baby to grow. Just like you need warm clothes in winter, baby chick needs warmth inside egg.

Points to Remember

A hen lays eggs in a nest.
The hen sits on eggs to keep them warm.
This sitting is called hatching.
Chicks grow inside the warm egg.
A chick breaks the shell and comes out.

Metamorphosis

There are similarities between a goat and its kid, and between a hen and her chick. However, a caterpillar and a butterfly are very different.

Thus, in some animals, the young one grows into an adult animal that looks very different from the young one. This change of form is called metamorphosis.

Metamorphosis In A Butterfly

Butterflies of various shapes and beautiful colours are a part of our environment. They live their life among plants.

As butterflies grow, they pass through four stages. These are egg, larva, pupa and adult. The adult stage is called butterfly.

The Plain Tiger butterfly is a very common one. Let us take its example to see how the growth of a butterfly takes place.

The female Plain Tiger butterfly lays an egg on the milkweed (rui) leaf. In six to eight days, the larva emerges from the egg. The larva of a butterfly is called a caterpillar.

When the caterpillar comes out of the egg it is very hungry. It begins to nibble and eat the very leaf on which it emerges from the egg. It eats very fast. So, its growth is very rapid.

A new term: moult - to shed old skin to make way for new growth.

The caterpillar of the Plain Tiger butterfly grows so rapidly in the first two or three days that it does not fit in its skin anymore. But under the old skin, a new loose skin is formed on the growing caterpillar. Then, the caterpillar sheds the old skin. That is, it moults.

Teacher's Note

You can find caterpillars on plants in your garden during monsoon. Green caterpillars eat leaves very fast and they grow quickly.

Exam Trick

Remember: Moult = remove old dress, wear new dress. Caterpillar moults four times because it grows very fast and old skin becomes too small.

Points to Remember

A caterpillar is a baby butterfly and looks very different.
Caterpillar eats leaves and grows very fast.
It moults four times, which means it sheds old skin.
Each time it moults, a new skin is ready underneath.
This change of form is called metamorphosis.

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