spermatidium

A spermatidium is a mature sperm cell that is capable of fertilizing an egg. It is the final stage in the development of sperm cells, following the process of spermatogenesis. Spermatids undergo a series of morphological changes and acquire the ability to swim and fertilize an egg. The process of spermatogenesis occurs in the seminiferous tubules of the testes in males. It begins with the division of spermatogonia, which are stem cells located in the basal layer of the seminiferous tubules. These cells undergo mitosis to produce primary spermatocytes, which then undergo meiosis to produce secondary spermatocytes. The secondary spermatocytes undergo another meiosis to produce spermatids. The spermatids then undergo a process called spermiogenesis, during which they lose most of their cytoplasm and acquire a flagellum, becoming mature sperm cells or spermatids. Spermatids are characterized by their elongated shape and the presence of a nucleus that contains the genetic material necessary for fertilization. They are also surrounded by a plasma membrane and a layer of cytoplasm. Spermatids are typically motile and can swim through the female reproductive tract to reach the egg. Once fertilization occurs, the spermatid's nucleus fuses with the egg's nucleus, resulting in the formation of a zygote.