Question

Animal eggs with rich yolk content are called
a. Microlecithal
b. Homolecithal
c. Telolecithal
d. Alecithal

Answer 1

Hint: The yolk is the nutrient-bearing portion of the egg among animals producing eggs whose primary function is to supply food for the embryo 's development.

Complete answer:
- When the egg contains a small or negligible amount of yolk it is said to be microlecithal.
- The very small amount of yolk present is equally distributed in the ooplasm in Homolecithal eggs. Usually, this condition is observed in eggs with very little yolk content.
- The distribution of yolk in eggs containing moderate or large quantities of yolk is not uniform. More towards the vegetal pole, lt is concentrated. Such a type of egg, in which the yolk is concentrated towards one pole, is called telolecithal egg.
- When no yolk is present in the shell, it is considered an alecithal shell.
- So here we can conclude that telolecithal egg is which has rich yolk content among the given options.

Hence, the correct answer is option (C).

Additional information:
Yolks are often rich in vitamins, minerals, lipids and proteins as stored food. Protein functions partly as a food in its own right, and partly to regulate the storage and availability of other nutrients. For instance, the amount of yolk in an egg cell in some species influences the developmental processes that follow fertilisation.

The yolk is not protoplasm-like living cell material, but mainly passive material, i.e. deutoplasm. During oogenesis, food materials and associated control structures are supplied. Any of the substance is stored more or less in the manner in which it is supplied by the maternal body, partly as processed in the egg by dedicated non-germ tissues, while part of the biosynthetic processing takes place in the oocyte itself in its final form.

Note: Some types of eggs do not contain yolk, for example because they are laid in circumstances where there is adequate food supply (such as in the body of a parasitoid host) or because the embryo grows in the body of the parent that provides the food, normally via a placenta.