Spermatogenesis · Spermatogenesis is the process of formation of haploid, microscopic and functional male gametes, spermatozoa from spermatogonia present in testes. · It occurs in the seminiferous tubules of the testis and consists of the following phases. (i) Multiplication phase: · It includes rapid mitosis of primordial germ cells present in the germinal epithelium of seminiferous tubules. · As a result, a large number of diploid and round sperm mother cells, called spermatogonia, are formed. (ii) Growth phase: · Each spermatogonium increases in size (about twice) due to the accumulation of nutritive materials in the cytoplasm and the replication of DNA and forming a diploid primary spermatocyte. · This phase is of much shorter duration than in oogenesis. (iii) Maturation phase: · Each primary spermatocyte by meiosis, I and II, produces four spermatids. · Spermatids separate out in spermiogenesis. iv) Spermiogenesis...