Question

Assertion: A mutual exchange of sperms occurs between two earthworms during mating.
Reason: Mature sperms and egg cells and nutritive fluid are deposited in cocoons produced by gland cells of clitellum.

• A. If both assertion and reason are true and reason is the correct explanation of assertion.
• B. If both assertion and reason are true but reason is not the correct explanation of assertion.
• C. If assertion is true but reason is false.
• D. If both assertion and reason are false.

Answer 1

Answer: (B)

The earthworms are bisexual or hermaphrodite or monoecious and protandrous. The self-fertilization is not possible in the earthworm because of the relative position of openings of male and female reproductive organs, hence cross fertilization takes place.
During mating, two worms attach themselves with their ventral surfaces and become opposed to each other in opposite direction to exchange packets of sperms called spermatophores. Mature sperm and egg cells and nutritive fluid are deposited in cocoons, produced by the gland cells of clitellum. The ova (eggs) are fertilized by the sperm cells within the cocoon which then slips off the worm and is deposited in or on the soil. The cocoon holds the worm embryos. After about 3 weeks, each cocoon produces two to twenty baby worms with an average of four.