Question

Explain the process of spermatogenesis in humans.

Answer 1

The process of formation of sperms is called spermatogenesis. It occurs in the male gonads testis. Testes are made up of many seminiferous tubules lined by germinal epithelium. Cells of this layer divide to form spermatozoa in the following steps:

(1) Multiplication Phase: At maturity, the primordial germ cells divide by mitosis to produce a large number of spermatogonia. Type A spermatogonia is the stem cells which divide to form spermatogonia. Type B spermatogonia are the precursors of sperms.

(2) Growth Phase: Type B spermatogonium actively grows to a primary spermatocyte. It obtains nourishment from the nursing cells.

(3) Maturation Phase: Each primary spermatocyte undergoes two maturation divisions. The first maturation division is reductional and forms two haploid daughter cells called secondary spermatocytes. Both secondary spermatocytes then undergo second maturation division to form four haploid spermatids.

(4) Spermiogenesis: It is the process of transformation of spermatid to a spermatozoan. The spermatozoa are then known as sperms. The four spermatid becomes the head of the sperm, the Golgi apparatus, containing proteolytic enzymes, becomes the acrosome cap.