Where do the testes originate in a fetus?

Correct Answer: C

Rationale: The testes originate in the abdominal cavity in a fetus. During development, they descend into the scrotal sac through the inguinal canal. This process is essential for proper sperm production as the scrotal environment provides optimal temperature for sperm development. The other choices are incorrect because the testes do not initially form in the scrotal sac, pelvic cavity, or retroperitoneal space. The correct sequence of descent from the abdominal cavity to the scrotal sac is crucial for normal reproductive function.

Correct Answer: D

Rationale: The correct answer is D: zygote. A zygote is formed when a sperm cell fertilizes an egg cell, resulting in a single cell with a full set of 46 chromosomes. This process is called fertilization and marks the beginning of a new individual. The other choices (A: spermatozoon, B: polar body, C: ovum) are not correct because a spermatozoon is a mature sperm cell with 23 chromosomes, a polar body is a byproduct of meiosis in the female reproductive system and has only 23 chromosomes, and an ovum is an unfertilized egg cell also containing 23 chromosomes.

Correct Answer: A

Rationale: The correct answer is A: labia major. The scrotum in males corresponds to the labia major in females as they both serve as protective structures for the reproductive organs. The labia major in females is analogous to the scrotum in males in terms of function and location. The other choices are incorrect because the labia minor (B) is a smaller structure located inside the labia major, the pudendal cleft (C) refers to the space between the labia major and labia minor, and the mons pubis (D) is a rounded, fatty area located over the pubic bone.

Correct Answer: A

Rationale: The correct sequence is A: FSH, as it initiates the menstrual cycle by stimulating the growth of follicles in the ovaries. LH then triggers ovulation. Estrogen is produced by the developing follicles and peaks before ovulation, while progesterone rises after ovulation. The other choices are incorrect as they do not follow the physiological sequence of hormonal actions in the menstrual cycle.

Correct Answer: B

Rationale: The correct answer is B (44 autosomes) because a human primary spermatocyte is a diploid cell containing a total of 44 autosomes. This is because humans have 22 pairs of autosomes in their somatic cells. During meiosis I, the primary spermatocyte undergoes replication and recombination, resulting in 22 pairs of autosomes (44 autosomes) that will be divided into two haploid secondary spermatocytes. Choices A, C, and D are incorrect because they do not reflect the correct number of autosomes present in a human primary spermatocyte.