91影视

Semen is a mixture of sperm and spermatic duct secretions (about 10 percent of the total) and fluids from accessory glands that contribute most of the semen鈥檚 volume. Sperm are haploid cells, consisting of a flagellum as a tail, a neck that contains the cell鈥檚 energy-producing mitochondria, and a head that contains the genetic material.

The correct option is c. seminiferous tubules

Sperm mature in seminiferous tubules that are coiled inside the testes ,The walls of the seminiferous tubules are made up of the developing sperm cells, with the least developed sperm at the periphery of the tubule and the fully developed sperm in the lumen. The sperm cells are mixed with 鈥渘ursemaid鈥� cells called Sertoli cells which protect the germ cells and promote their development .