Question

Cleidoic eggs are characteristic of

• A. fishes and amphibians
• B. birds and reptiles
• C. amphibians and reptiles
• D. birds and mammals

Answer 1

The correct option is B

birds and reptiles

The correct option is B.

Explanation of the correct option:

1. Cleidoic eggs are laid outside of water and contain a protective shell.
2. The shell can be flexible or calcareous, and it is air-permeable (hard).
3. All of the nutrition an embryo requires to grow into a hatchling is present in the eggs.
4. The cleidoic egg is significant because it allows reproduction outside of water, which is often the case.
5. Birds and Reptiles lay eggs to birth to their young ones.
6. The eggs they lay have hard protective covering around the embryo which protects the embryo from the environment.
7. This kind of covering of eggs is known as Cleidoic eggs which is a characteristic of Birds and Reptiles.

Explanation of the incorrect options:

Option A :

1. Fishes and amphibians lay their eggs directly inside water and don't require any protection from the outside environment.
2. Fish can reproduce by laying eggs or by giving birth to live offspring.
3. Amphibians reproduce by producing eggs without a hard shell or soft skin.
4. The majority of females deposit their eggs in the water, and the young, known as larvae or tadpoles, dwell there, using their gills to breathe and foraging for food like fish.
5. So this option is incorrect.

Option C :

1. Amphibians lay their eggs in water so don't need much protection.
2. Reptiles lay their eggs outside water, and on land so require protection from the outside environment.
3. So this option is incorrect.

Option D :

1. Cleidoic eggs are defined as having a thick, rigid outer shell made of calcium carbonate.
2. Birds, insects, reptiles, and mammals that lay eggs have cleidoic eggs, which are an adaption for the land.
3. Birds lay eggs on land so require protection from the outside environment but Mammals don't lay eggs.
4. So this option is incorrect.

Final answer: Cleidoic eggs are characteristic of birds and reptiles.