Final answer:
Spermatogenesis occurs with the aid of nearby Sertoli cells that also nourish the developing sperm cells. (option b)
Step-by-step explanation:
Sertoli cells aid in spermatogenesis and nourish sperm by secreting signaling molecules and creating the blood testis barrier. Sertoli cells, also known as sustentacular or sustentocyte, are essential for the process of spermatogenesis and can be found within the epithelial tissue of the seminiferous tubules in the testes. They not only provide nutrients to the germ cells but also secret signaling molecules that are crucial for sperm production. Additionally, they create a protective environment called the blood-testis barrier through tight junctions, which prevents harmful substances from reaching the germ cells and also prevents an autoimmune response by keeping the germ cell's antigens from entering the bloodstream.
Besides the nurturing role of Sertoli cells, Leydig cells are located between the seminiferous tubules and are responsible for producing testosterone, which is vitally important for the regulation of spermatogenesis. The diploid stem cells, called spermatogonia, begin the process by undergoing mitosis, eventually leading to the development of mature sperm cells through several stages, including the formation of primary spermatocytes, secondary spermatocytes, and finally spermatids which mature into sperm after several changes, including the development of a tail.