The sperm is a unique cell produced in the mammalian male. Its specialized ability to move enables it to migrate through the female genital tract and fertilize the oocyte in vivo or in vitro. Its basic function is to carry the 23 male chromosomes to the egg at fertilization, and form the zygote. Spermatogenesis follows a rigid time scale. Ap spermatogonia simultaneously become committed at circumscribed areas within each seminiferous tubule. Hence, growing cells form clusters, which develop at intervals (16 days) specific for that location. Spermatogenesis can be divided into four interdependent parts that are coordinated by factors emitted from the SC, peritubular cells, Leydig cells, and the vasculature following as proliferation (spermatocytogenesis), meiosis, differentiation (spermiogenesis), and spermiation. Various environmental factors such as high temperature, obesity, drugs, and occupational exposure have been seen to adversely affect spermatogenesis.