NCERT Solutions Curiosity Chapter 10 .5.2 — In-text Questions

Book page 20110 Updated on2026-09-05

Q1.

How are these eggs of a frog different from the other eggs that you may have seen?

Answer

Compare frog eggs with the hen's eggs you see in the kitchen.

Feature	Frog eggs (spawn)	Hen's egg
Covering	A soft, transparent jelly, no shell at all	A hard, brittle calcium shell
Number	Hundreds, stuck together in one white jelly-like cluster called spawn	Laid one at a time
Size and colour	Very small, each a dark dot inside a clear ball	Large, white or brown
Where they are laid	Floating on the water surface near the edge of a pond, often attached to plants growing in or around the water	On land, in a nest
Care by the parent	None — the eggs are left to develop on their own	The hen sits on them and keeps them warm
Can you see inside?	Yes — the developing embryo is visible through the jelly	No — the shell is opaque

Why frog eggs need no shell: a shell protects an egg laid in air from drying up. A frog's eggs are already in water, so they cannot dry out. The jelly instead does three other jobs — it holds the eggs together, it makes the cluster slippery and unpleasant for many predators, and it swells with water to cushion the eggs. But since so many eggs are still eaten, the frog lays hundreds so that at least a few survive.

Q2.

Which stage has the shortest duration?

Answer

The egg stage is the shortest. Read the timings printed in Fig. 10.8:

Stage	When it is reached	Roughly how long it lasts
Stage IA — Spawn	Day 1	2–3 days (the shortest)
Stage IB — Embryo	Day 3–4	about 4–6 days
Stage IIA — Tadpole with tail	Day 7–10	about 7 weeks
Stage IIB — Tadpole with legs	8–10 weeks	about 2–3 weeks
Stage III — Froglet	12 weeks	about 2 weeks
Stage IV — Adult frog	14 weeks	the rest of its life

Day 1 → Day 3–4 = only about 3 days as an egg

Why the egg stage is hurried: an egg cannot swim, hide or feed. It is completely helpless and is eaten by fish, insects and birds. The sooner it hatches into a tadpole that can at least swim away, the better its chances.

Q3.

Is there a change in the habitat during the various stages in the life cycle of a frog?

Answer

Yes — and this is one of the most striking things about a frog. It begins life entirely in water and ends up able to live both in water and on land.

Stage	Habitat	Body features that suit it
Egg / embryo	Water only	Soft jelly coat that cannot dry out
Tadpole with tail	Water only	Long tail for swimming; no legs
Tadpole with hind legs	Water only	Tail still there, hind legs beginning to form
Froglet	Mostly water, but begins to spend some time on land	Four legs, tail growing shorter
Adult frog	Both water and land	No tail; strong hind legs for jumping and landing

Why the change is possible at all: the body is rebuilt in step with the move. The tail, which is useless on land, is gradually absorbed; the legs, useless to a swimmer with no room to kick, grow only when they will be needed. This is the same idea you saw in the mosquito — young and adult live in different places and are built differently for them.

Q4.

How do the special features support that stage?

Answer

Every feature at every stage is there for a reason. Match them up.

Stage	Special feature	How it helps
Spawn	Hundreds of eggs in one jelly mass	Many are eaten, so laying a large number ensures some survive; the jelly holds them together and cushions them
Tadpole (early)	A long tail, no legs	Tails help them swim in water — the only place they can live and feed
Tadpole (later)	Hind legs appear while the tail is still present	The animal can start pushing itself along the pond bed while it can still swim well
Froglet	Four legs, tail shrinking; it still lives in water but begins to spend some time on land	A safe halfway stage — it can practise moving on land yet return to water at once
Adult frog	Tail lost completely; legs become strong to help them jump and land	Strong hops let it catch insects on land and escape predators in one leap back into the pond

As the book describes it: tadpoles develop legs but still have tails; they grow gradually and start looking like little frogs called froglets; they continue to grow and lose their tails completely; and they become fully developed adult frogs who live both in water and on land.

Did you know? The tail is not simply thrown away. Its material is absorbed back into the body and used up while the froglet is changing — which is why a froglet can manage for a while without eating much.

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