Question

Insect egg is
a. Homolecithal
b. Telolecithal
c. Centrolecithal
d. Alecithal

Answer 1

Hint In isolecithal, the yolk is present in small concentration, whereas in telolecithal, there is an uneven distribution of the yolk in the cytoplasm, in the case of centrolecithal all the distribution of the egg is at the center of the egg, and in the alecithal, the amount of the yolk is very less or there is no yolk.

Complete answer:

Centrolecithal eggs are the type of eggs in which all the distribution of the egg is at the center of the egg which is surrounded by the cytoplasm. It is the type of characteristics of the insects.

The second option is the telolecithal which is the wrong answer because, in telolecithal, there is an uneven distribution of the yolk in the cytoplasm, which is mostly seen in the case of birds, reptiles, etc but not in insects hence this option is not true.

The first option in the question is isolecithal, in which the yolk is present in small concentration and it is being distributed all over the cytoplasm in uniform condition.
This is mostly seen in the case of sea urchins, tunicates, etc but not seen in insects hence this option is also not true.

The last option is alecithal which is also not the correct option, as in alecithal, the amount of the yolk is very less or there is no yolk, hence it is mostly seen in the case of oviparous, hence this is not found in insects, so this option is also not correct.

Hence, the correct answer to this question is the third option that is (c) centrolecithal.

Note:
- During the occurrence of cytokinesis, the centrolecithal zygotes have to undergo cleavage that is meroblastic. Where the cleavage plane mostly extends to the yolk accumulated and is kind of superficial. Eggs are mainly the first stage present in the life cycle of most of the insects.
- Insects can lay their eggs singly or in clusters or can also lay them in a specialized structure called ootheca. Insects eggs are seen to be very small. Insects egg can be in the risk of desiccation or drying out if the female does not lay their eggs in the wrong place.