Final answer:
Sperm acquire motility during the process of capacitation in the female reproductive tract. They gain motility in the epididymis prior to entering the female genital tract.
Step-by-step explanation:
Sperm acquire motility during the process of capacitation in the female reproductive tract. Capacitation is the process by which sperm are prepared for fertilization and includes changes in their outer membrane that improve their ability to release digestive enzymes needed to penetrate an egg's outer layers. The fluids in the female reproductive tract help improve the motility of sperm by thinning the membrane of the sperm head and depleting cholesterol molecules.
Sperm are initially non-motile when produced in the testes, but they gain motility while passing through the epididymis. The epididymis is a coiled tube attached to the testis where sperm continue to mature. Once inside the female genital tract, sperm can swim independently towards the unfertilized egg.