(A) Think and tell :
1) It takes 20-22 days for a chick to emerge from a hen's egg. Would the young ones of other birds also take the same umber of days to hatch ?
Ans. Every bird has its own unique time to hatch. Even if a hen's egg hatches in 20 - 22 days, different birds take different number of days to hatch out .eg The number of days to hatch in different birds is as follows :
(1) Crow : 16 to 17 days
(2) Sparrow : 1 to 14 days
(3) Pigeon : 17 to 19 days
(4) Peacock : 27 to 29 days,
The least period for hatching is 11 days while the maximum number of days for hatching eggs is 64 days as in penguin. out.
2) You must have seen dragon flies hover over grass. Which stage of their life cycle is this-the egg, larva, pupa or adult?
Ans. Dragon fly is an adult stage.
3) When you take a bunch of a leafy vegetable to sort it, you may find holes of different sizes in the leaves. Some leaves may have been nibbled at the edges. What do you think is the reason for that?
Ans. Some insects lay their eggs on the leaves of vegetable. These eggs grow into caterpillars. These caterpillars nibble at the leaves. Due to this, there are holes on the leaves and nibbled edges. Some types of snails also nibble at leaves as this is their favourite food.
4) When you take some peapods to shell, you sometimes see tiny green living things inside the pod. Which of the four stages of the life cycle of an insect are they?
Ans. The tiny green living things which are seen inside the peapods are larvae or caterpillars of some insect. They feed upon the peas and later become adult insects.
(B)Answer in brief.
1) Why must the hen sit on her eggs?
Ans: The chicks grow inside the eggs. They need warmth for the growth. Therefore, mother hen sits on the eggs to give warmth This warmth helps the chick to grow and hatch. Therefore, hen must sit on her eggs.
2) Why does a hen become aggressive when she is hatching her eggs?
Ans. Hen is alert and she fears for the safety of her eggs. So in order to protect the eggs from intruders, she becomes aggressive when she is hatching her eggs.
3) Which are the four stages of the life cycle of a butterfly?
Ans. Egg, larva or caterpillar, pupa and adult are the four stages of the life cycle of a butterfly.
4) What changes take place inside the chrysalis of the Plain Tiger butterfly?
Ans. Plain Tiger butterfly pupa stops feeding completely and shows following changes in the body :
(1) Its legs grow longer.
(2) It develops attractive wings.
(3) The body grows completely and pupa turns into an adult butterfly.
(C) True or false?
1) A lamb emerges from an egg. (False)
2) We cannot easily see the eggs of an ant because they are very True tiny.( True )
3) When the caterpillar emerges from the egg, it is not very hungry. (False)
(D) Fill in the blanks.
1) The female butterfly lays __eggs__ on the leaves of a plant.
2) The larva of a butterfly is called a ___caterpillar___.
