Primary spermatogonium undergo:

Correct Answer: B

Rationale: The correct answer is B. Primary spermatogonium undergo mitosis to replicate and maintain the diploid chromosome number, then meiosis to reduce the chromosome number, resulting in secondary spermatocytes. Choice A is incorrect as it skips meiosis. Choice C is incorrect as it suggests two meiotic divisions from primary spermatogonium, which is not accurate. Choice D is incorrect because it fails to mention the initial step of mitosis before meiosis in the process.

Correct Answer: D

Rationale: The correct answer is D: 23. Sperm cells are haploid, meaning they contain half the number of chromosomes as normal body cells. In humans, normal body cells have 46 chromosomes (23 pairs), while sperm cells have only 23 chromosomes. This is essential for maintaining the correct chromosome number after fertilization. A: 1 - Incorrect. Sperm cells cannot have only 1 chromosome as they need to contribute genetic material during fertilization. B: 2 - Incorrect. Having only 2 chromosomes would not provide sufficient genetic diversity for offspring. C: 12 - Incorrect. This number does not align with the haploid nature of sperm cells in humans with 23 chromosomes.

Correct Answer: B

Rationale: The correct answer is B: ovulation. Ovulation is the process where the ovarian follicle ruptures and releases an ovum. This occurs around the middle of the menstrual cycle. Menopause (A) is the cessation of menstrual periods, not the release of an ovum. Implantation (C) is the attachment of a fertilized egg to the uterine wall, not the release of an ovum. Breast (D) is not related to the process of ovulation.

Correct Answer: A

Rationale: The correct answer is A: dysmenorrhoea. Dysmenorrhoea specifically refers to abdominal pain caused by uterine cramps during menstruation. "Dys-" means difficult or painful, and "menorrhoea" refers to menstruation. Choice B, hypermenorrhoea, refers to abnormally heavy menstrual bleeding, not abdominal pain. Choice C, menometrorrhagia, refers to irregular and excessive uterine bleeding, not specifically related to abdominal pain. Choice D, polymenorrhoea, refers to frequent menstrual cycles, not abdominal pain. In summary, dysmenorrhoea is the correct answer because it accurately describes the abdominal pain associated with uterine cramps during menstruation, while the other choices pertain to different menstrual abnormalities.

Correct Answer: A

Rationale: Rationale for Correct Answer A: The efferent ducts continue the rete testis. This is true because the efferent ducts are a series of small ducts that connect the rete testis to the epididymis. The rete testis is a network of tubules located at the back of the testicle where spermatozoa from the seminiferous tubules are collected. Therefore, the efferent ducts serve to transport spermatozoa from the rete testis to the epididymis for further maturation. Summary of Incorrect Choices: B: Opening in the epididymal duct is incorrect because the efferent ducts lead into the epididymis, not the epididymal duct itself. C: Opening in the deferent duct is incorrect because the efferent ducts do not lead directly into the deferent duct, but rather connect the rete testis to the epididym