Spermatogonia are the youngest germ cells from which spermatozoa proliferate. These lie next to the basement membrane and undergo series of mitotic divisions leading to the formation of primary spermatocytes. The primary spermatocytes undergo the first meiotic division and give rise to haploid cells called secondary spermatocytes.
The secondary spermatocytes begin the second meiotic division and produce smaller cells called spermatids. The spermatids later transform into spermatozoa by a process known as spermiogenesis. The transformation of spermatids into spermatozoa involves principally cytoplasmic loss and the differentiation of the tail piece.