Gametogenesis

Correct answer: B. Spermatogenesis

Explanation: Spermatogenesis is the process by which diploid germ cells in the seminiferous tubules develop into haploid spermatozoa through mitotic multiplication, meiosis, and maturation. Oogenesis produces ova, fertilisation joins male and female gametes, and implantation is attachment of an early embryo to the uterine lining. Therefore option B is the only correct process.

Correct answer: B. Oogenesis

Explanation: The formation and maturation of female gametes, or ova, is called oogenesis. It begins in the ovaries and involves the development of oogonia into primary oocytes and, after meiotic changes, a mature ovum. Spermatogenesis produces sperm, fertilisation fuses gametes, and parturition means childbirth; therefore, option B is correct.

Correct answer: A. Transformation of spermatids into mature spermatozoa

Explanation: Spermiogenesis is the terminal differentiation step of spermatogenesis. During this process, haploid spermatids do not divide further; instead, they undergo changes such as nuclear condensation, acrosome formation, development of the flagellum, and loss of excess cytoplasm to become streamlined spermatozoa. The actual release into the seminiferous-tubule lumen is spermiation, so option A is correct.

Correct answer: A. Release of mature spermatozoa from Sertoli cells into the lumen of seminiferous tubules

Explanation: Spermiation is the final release step of sperm formation: mature spermatozoa detach from the Sertoli-cell surface and enter the lumen of a seminiferous tubule. It must be distinguished from spermiogenesis, in which spermatids are structurally transformed into spermatozoa. Ovulation is the release of a secondary oocyte, while acrosome formation occurs during differentiation. Hence, option A is correct.