wild populations had been lost. Gametogenesis Gametogenesis is the formation of gametes, or reproductive cells. Spermatogenesis Spermatogenesis is the production of sperm cells in the testis. In mature testes primordial germ cells divide mitotically to form the spermatogonia, which in turn generate spermatocytes by mitosis. Then each spermatocyte gives rise to four spermatids through meiosis. Spermatids are now haploid and undergo differentiation into sperm cells. Later in reproduction the sperm will fuse with a female oocyte to form the zygote. Oogenesis Oogenesis is the formation of a cell who will produce one ovum and three polar bodies. Oogenesis begins in the female embryo with the production of oogonia from primordial germ cells. Like spermatogenesis, the primordial germ cell undergo mitotic division to form the cells that will later undergo meiosis, but will be halted at the prophase I stage. This is known as the primary oocyte. Human females are born with all the primary oocytes they will ever have. Starting at puberty the process of meiosis can complete resulting in the secondary oocyte and the first polar body. The secondary oocyte can later be fertilized with the male sperm. References Bibliography Lombardi, Julian (1998). Comparative Vertebrate Reproduction. Kluwer Academic Publishers, Boston. link. Reproduction