Question

The type of egg in cockroach is called as
A. Microlecithal
B. Centrolecithal
C. Isolecithal
D. Telolecithal

Answer 1

Hint: Cockroaches belong to the phylum Arthropoda and class Insecta. They are also known as roaches. The eggs of cockroaches consist of the yolk and the albumin. Albumin is in whitish color and inside it yolk is present which is yellowish in color. In the cockroaches, yolk is majorly found concentrated in the middle of the egg cell.

Complete answer:
Eggs are mainly classified into three types depending upon the distribution of yolk namely, isolecithal or homolecithal eggs, telolecithal eggs and centrolecithal eggs.
Isolecithal or homolecithal eggs: These eggs contain a little amount of yolk that is distributed in a uniform manner throughout the cytoplasm of egg.
Telolecithal eggs: In these eggs, the yolk is distributed in a non uniform manner. It mainly concentrated around one pole which may be a vegetable pole or animal pole.
Centrolecithal eggs: Here, the yolk is found concentrated at the centre of cytoplasm of the egg cell. The examples of such eggs are insects like cockroaches.
Yolk mainly comprises proteins which play a major role in embryonic development.

So, the correct answer is option “B” , which is the type of egg in a cockroach called Centrolecithal.

Note: An egg or ovum is referred to the female gamete which is fully developed. The egg is non motile. The egg or female gamete is comparatively larger in size than the male gamete. Egg is often associated with various functions. The haploid set of chromosomes is provided to the developing embryo by the egg. Egg is also responsible for providing nourishment and food to the developing embryo. Moreover, the cytoplasm of the embryo is also obtained from the egg.