Question

Schematically represent and explain the events of spermatogenesis in humans.

Answer 1

a. In a testis at puberty, spermatogonia produce sperms by the process of spermatogenesis.
b. The spermatogonia multiply by mitotic division and increase in numbers.
c. Each spermatogonium is diploid and contains 46 chromosomes.
d. Some of the spermatogonia called primary spermatocytes periodically undergo meiosis.
e. A primary spermatocyte completes the first meiotic division (reduction division) leading to formation of two equal haploid cells called secondary spermatocytes having only 23 chromosomes each.
f. The secondary spermatocytes undergo the second meiotic division to produce four equal, haploid spermatids.
g. The spermatids are transformed into spermatozoa (sperms) by the process, called spermiogenesis.