Regarding respiratory system of fetus

Correct Answer: A

Rationale: The correct answer is A because the respiratory bud does indeed start to appear at the ventral wall of the foregut around week 10 of gestation. This marks the beginning of respiratory system development. Choice B is incorrect as there are actually 5 stages of respiratory system development. Choice C is also incorrect as the development of the respiratory tract is not fully complete until after birth, not just in the last week of fetal development. Choice D is incorrect because the epithelial respiratory lining is derived from endoderm, not endodermal.

Correct Answer: C

Rationale: The correct answer is C: secretion of alkaline mucus. The prostate gland produces alkaline mucus that helps neutralize the acidic environment of the vagina, thus enhancing sperm viability. Spermatogenesis (choice A) occurs in the testes, not the prostate. The production of glycogen (choice B) is not a function of the prostate. While the prostate does play a role in sperm transport and nourishment, it does not directly impact the maturation of sperm cells (choice D).

Correct Answer: C

Rationale: The correct answer is C (ovum) because the ovum is the mature and fertilized egg cell resulting from the fusion of a sperm cell and an egg cell during fertilization. The primary oocyte (A) is an immature egg cell that has not undergone fertilization. The secondary oocyte (B) is the egg cell released during ovulation but has not yet been fertilized. Oogonia (D) are the precursor cells that give rise to primary oocytes through the process of oogenesis. Therefore, the ovum is the only choice that accurately represents a fertilized egg cell.

Correct Answer: C

Rationale: The correct answer is C: vulva. The vulva includes the labia, clitoris, and vestibular glands. The labia are the outer folds of skin, the clitoris is a highly sensitive erectile structure, and the vestibular glands are located around the vaginal opening. The vulva encompasses all these structures, making it the most inclusive term among the options provided. The other choices are incorrect because they are specific structures that are part of the vulva but do not encompass all the other terms listed.

Correct Answer: B

Rationale: The correct answer is B: progesterone. Progesterone inhibits LH secretion by exerting negative feedback on the hypothalamus and pituitary gland. This hormone signals that the body has enough progesterone and does not need additional LH for ovulation. FSH (choice A) stimulates LH secretion, estrogen (choice C) typically increases LH secretion during the menstrual cycle, and LH (choice D) does not inhibit its own secretion.