Question

Why a calcite shell is present in hen's egg and absent in frog,s egg

Answer 1

Answer:

A calcite shell is present in hen's egg and absent in frog's egg. There are several reasons for this like protection, fertilization, etc.

Explanation:

An egg is the result of the fertilization of an egg cell. It is an organic vessel that contains a zygote in which the development of an embryo takes place. Eggshell is the outer covering of an egg, which is commonly made up of calcium carbonate. Most of the bird's eggshells are hard and made up of calcium carbonate while in frogs they don't have an eggshell. There could be several reasons for this, and some of them are,

• even though the frog's eggs lack an eggshell, they have a jelly-like covering of glycoprotein that helps to float on water, holds the eggs together and prevents them from sinking, and also protects from other animals.

• Since the eggs of frogs are not fertilized when laying, if the hard calcite shells were present, it would be difficult for the eggs to get fertilized.

• Eggs of hens are fertilized internally and laying on land with the zygote inside the egg, so it needs more protection as they are very vulnerable to the surroundings.