(a) Draw a diagrammatic sectional view of a seminiferous tubule (enlarged) of human male and label (i) Spermatogenium, (ii) Sertoli cell, (iii) Primary spermatocyte. Write the function of each labelled part.
(b) Differentiate between spermatogenesis and spermiogenesis.

Explanation

(a)
(i) Spermatogeniun : the spermatogonia (sing. Spermatogenium) present on the inside wall of seminiferous tubules multiply by mitotic division and increase in numbers. It is diploid and contains 46 chromosomes. Some of the spermatogonia are called primary spermatocyte.
(ii) Primary spermatocyte : Completes the first meiotic divisions leading to formation of two equal, haploid cells called secondary spermatocyte.
(iii) Sertoli cells : After spermiogenesis, sperm heads become embedded in the sertoli cells and are finally released from the seminiferous tubules by process called spermiation.