Question

What is the function of the seminal vesicles in an earthworm?

Answer 1

Hint: The earthworms belong to the phylum Annelida. Their body surface is divided into distinct segments. They are mainly terrestrial organisms and are mostly found in soil.

Complete answer:
Earthworms are invertebrates. Most of the species are parthenogenetic, where the embryo develops without fertilization. Their life span varies from 4-8 years under protective conditions. Each earthworm carries both male and female sex organs. Thus they are known as hermaphrodites. Reproduction in earthworms is mostly sexual. The male reproductive organ matures earlier than a female one. Thus cross-fertilization is more common in earthworms. The male reproductive organ of earthworm includes a pair of testis sac and two pairs of testes in the 10th and 11th segments. The testis sacs are linked with two pairs of seminal vesicles, which are large white sacs. The seminal vesicles are present in the male reproductive organ, following the testis sacs. Each pair of seminal vesicles is present on the 11th and 12th segments respectively. It receives spermatogonia from the testis sacs. Further, spermatogonia mature and develop into spermatozoa. Seminal vesicles also provide nourishment to the sperms.

Note:
-Self-fertilization is absent in earthworms.
-Earthworms play a great role in increasing the fertility of soil. Thus they are also known as 'Farmer's friend'.
-They are used to prepare 'compost' all over the world.
-Earthworms can also regenerate the segments again after losing it once.