Answer and Explanation:
Spermatogenesis takes place in the walls of seminiferous tubules. The outer surface of the tubules is a single layer of cells forming the germinal epithelium. Its actively dividing cells are diploid and are called primordial germ cells. They undergo mitosis to form spermatogonia. The spermatogonia enlarge considerably to form the primary spermatocytes which undergo meiosis giving rise to secondary spermatocytes.
