Final answer:
During spermiogenesis, spermatids become motile sperm cells known as spermatozoa. This involves structural changes to form a head and tail, DNA condensation, and maturation in the epididymis, as part of the larger process of spermatogenesis.
Step-by-step explanation:
During spermiogenesis, spermatids are transformed into motile cells called spermatozoa or sperm. This transformation involves the formation of a tail, condensation of DNA, and the removal of excess cytoplasm and organelles. They undergo major changes which include developing a head, midpiece, and flagellum.
The process begins with spermatogonia, which are diploid stem cells in the testes that undergo mitosis to maintain their population and produce primary spermatocytes. The primary spermatocytes undertake meiosis I to form two haploid secondary spermatocytes, and after meiosis II, they divide into a total of four haploid spermatids. These spermatids, initially similar in appearance to earlier cell stages, emerge from a round shaped, central nucleus-bearing form into the streamlined and highly specialized sperm cells, capable of fertilizing an egg.
Complete maturation occurs as these developing sperm move towards the lumen of the seminiferous tubules and eventually reach the epididymis, where they gain the ability to swim. This entire process from spermatogonia to spermatozoon is known as spermatogenesis, a critical component of male fertility.