Question

Non- cleidoic eggs occurs in
A. Birds
B. Fish
C. Reptiles
D. Platypus

Answer 1

Non- cleidoic cells have a delicate outer covering and are laid in water. They grow and mature in water before getting fertilized. They do not have a hard coating, so they are prone to dryness, which can be prevented by laying them in water. Hence, they require water.

Complete answer:
There are different ways to classify the types of eggs and one is based on the shell and requirement of water.
-Cleidoic eggs are those which are laid outside water and they have a protective shell around them. This shell is porous to air and is made hard with calcium or flexible. It contains food stored for the embryo to develop after fertilization occurs. The significance of these eggs is that they help in reproduction out of water.
-Similarly, Non-cleidoic cells are those which require water for reproduction and are laid in water. All viviparous animals lay their eggs in water. They do not contain proper nutritive storage in the yolk.

The birds lay eggs out of water in the air, hence their eggs are of the cleidoic type.
Therefore, option (a) is incorrect.
The reptiles are also the ones who lay eggs on land, especially in the sand, so they are also cleidoic.
Therefore, option (c) is also incorrect.
Platypus is an egg-laying mammal that also lays its eggs outside water, hence option (d) is also incorrect.
Only fishes lay their eggs in water with a delicate outer covering which needs to be protected. They require water for fertilization and reproduction occurs outside the body in water.

Hence, the correct answer is option (B).

Note: Cleidoic eggs are found in aves, mammals, and reptiles. They have calcium carbonate shells that protect the embryo and prevent dryness outside water in the land. They have terrestrial adaptation.
Non-cleidoic cells are delicate with a very soft coating, hence they require to be in the water to prevent them from drying.