Question

In telolecithal eggs, the yolk is present
A. On one side
B. On both sides
C. Towards vegetal poles
D. Throughout the egg

Answer 1

The yolk can be understood as food deposits in the eggs of animals that provide the necessary energy for the growth and developmental process of the embryo. Eggs or ova can be classified on the basis of the amount of yolk as well as the position of the yolk inside the eggs. The yolk can either be present on the animal or vegetative pole.

Complete step by step answer: In the eggs of many vertebrates, they have a large amount of yolk constituted at one particular end such as the vegetal pole. The yolk free pole is known as the animal pole, and the yolk is unequally distributed in the ooplasm, these kinds of eggs are known as telolecithal eggs. It is mostly found in birds, amphibians and fishes. This type of egg undergoes discoidal meroblastic cleavage, where the yolk is not incorporated in the cells during cell division. In telolecithal eggs, the yolk can’t be in either one of the sides, that is it cannot be in the animal pole and can be found only in the vegetal pole. When the yolk is present throughout the egg, it is known as isolecithal or homolecithal eggs. It has an even distribution throughout the ooplasm.
Thus, the correct answer is option C.

Note: The eggs can also be classified on the basis of the amount of yolk present in them into alecithal; where no yolk is present, macrolecithal; where a large amount of yolk is present, microlecithal: where a small amount of yolk is present and mesolecithal; when a moderate amount of yolk is present inside the eggs.