Question

Arrange the following events of spermatogenesis:

i. The spermatogonia give rise to 4 primary spermatocytes (2n)

ii. The spermatogonia divide mitotically to maintain the germ cells (2n)

iii. Spermiogenesis

iv. Each primary spermatocyte gives rise to 2 secondary spermatocytes (n)

• A. iii, ii, i, iv
• B. ii, i, iv, iii
• C. iii, i, ii, iv
• D. ii, iii, i, iv

Answer 1

The correct option is B

ii, i, iv, iii

The seminiferous tubules have diploid germ cells called spermatogonia which constitute the germinal epithelium. These spermatogonia divide mitotically to maintain the germ cell layer and also undergo different stages of differentiation to eventually form spermatozoa (sperms). Some of these spermatogonia divide mitotically twice to produce 4 primary spermatocytes each. Then each of the 4 primary spermatocytes, which are still diploid, undergo meiosis to produce 2 haploid secondary spermatocytes. The primary spermatocytes periodically undergo meiosis and finally form spermatids with 23 chromosomes. Spermatids then finally undergo spermiogenesis, in which they are stripped down and remodelled to form highly specialised spermatozoa.