Question

Cleidoic eggs are characteristics of
A. Mammals
B. Reptiles, birds, and insects
C. Insects only
D. Fishes

Answer 1

Hint: Cleidoic eggs are certain eggs that have an outer cover that is made out of water. The shell is porous to sunlight, and it can be flexible or calcareous (hard). Eggs provide all nutritive food required by the embryo to turn into a hatchling.

Complete answer:
Cleidoic eggs are the type of egg which reptiles and birds lay, The reproduction of mammals has progressed from laying cleidoic eggs to live birth. Cleidoic egg is often referred to as an amniotic egg because it is characteristic of amniotes, which have a protective shell that is made out of water. The shell is porous to the air and can be flexible or calcareous (hard). Eggs provide all the food that the embryo requires to turn into a hatchling. The importance of the cleidoic egg is that it makes reproduction out of, and sometimes out of, water. Eggs of insects and birds are sealed in a protective membrane to prevent the exchange of water, gases, etc. These types of eggs are found in insects, reptiles, and birds.
Hence, the correct answer is an option (B)-‘Reptiles, birds, and insects.

Note: Cleidoic egg is an ecological innovation that has facilitated the invasion of a wide variety of new environments and has contributed to one of the greatest adaptive radiations in the history of vertebrates. In contrast, the amphibians, whose reproduction is bound to water, are represented today by only a few highly specialized classes.