Question

If the earthworm releases the cocoons from the posterior end instead of the anterior end then...
A. Digestion will be affected.
B. Only one zygote will be formed in a cocoon.
C. Several zygotes will be formed in a cocoon.
D. Sperm will not reach cocoons and fertilization will not take place.

Answer 1

Hint: Earthworm is hermaphrodite in nature in earthworm both male and female reproductive systems are present in one same organism.

Complete answer: 1. The reproductive organs of the earthworm are located in the 9th to 15th segment of the earthworm.
2. Earthworm is a long tubular organism that is divided into several scales on the epidermis which are visible from the outside.
3. Cocoons are the female gametophyte that is obtained from the egg after the secretion of the viscous liquid fluid from the clitellum which initiates cocoons formation.
4. During mating, the sperm is directly injected into the cocoons for the formation of a new individual.
5. During mating for the exchange of the sperm two earthworms lined up one over the other so sperm can be exchange easily and the process of fertilization takes place smoothly.
6. During mating they lie one above the other but in opposite directions, the head of the one earthworm lies on the tail of the another.
7. In that situation if cocoons are released from the posterior end instead of the anterior end then the sperm does not come in contact with the eggs and the process of fertilization will not take place and zygote will not form.
8. Hence sperm will not reach the cocoons and the fertilization will not take place.

So option D is correct.

Note: Earthworm has both sexual and asexual mode of reproduction. Some of the earthworms are reproducing asexual by the process of regeneration.