What is the structure of a mature spermatozoon?

• A. Nucleus, mitochondria, flagellum
• B. Body, neck, tail
• C. Head, middle piece, and tail
• D. Head, shaft, tail

Answer: (C)

A mature spermatozoon is organized into three regions that align with its functions: the head, the middle piece, and the tail. The head houses a highly condensed nucleus with the paternal DNA and carries the acrosome, a cap containing enzymes needed to penetrate the egg. The middle piece is packed with mitochondria arranged around the axoneme to supply the energy (ATP) required for swimming. The tail, or flagellum, provides propulsion so the sperm can move toward the oocyte. This three-part arrangement is why describing the structure as head, middle piece, and tail is the correct choice. Other descriptions either don’t use the standard regional terminology or misplace components like mitochondria, which are specifically in the middle piece, not as a separate, distinct part.