The first polar body appears in the:

Correct Answer: D

Rationale: The correct answer is D because the first polar body is formed during the first meiotic division of the primary oocyte before birth. The primary oocyte undergoes meiosis I to form the secondary oocyte and the first polar body. This process occurs during fetal development, not after birth. Choice A is incorrect because the primary oocyte completes meiosis I to form the secondary oocyte and the first polar body before ovulation. Choice B is incorrect because the primary oocyte forms the first polar body before birth, not after birth. Choice C is incorrect because the first polar body is formed during meiosis I of the primary oocyte, not after fertilization.

Correct Answer: B

Rationale: Step-by-step rationale: 1. FSH stimulates development of follicles in ovaries. 2. Follicle cells release estrogen. 3. Estrogen levels increase as follicles develop. 4. Estrogen plays key role in menstrual cycle regulation. Therefore, the correct answer is B (estrogen). Other choices are incorrect: A (hormones are broad, not specific), C (progesterone is released after ovulation), D (implantation occurs in the uterus, not ovaries).

Correct Answer: C

Rationale: Step 1: The epididymis is a structure where sperm mature and are stored. Step 2: The deferent duct (vas deferens) carries sperm from the epididymis to the urethra. Step 3: Since the deferent duct crosses the epididymis, choice C is correct. Summary: Choices A, B, and D are incorrect because they do not accurately describe the anatomical relationship between the epididymis and the deferent duct.

Correct Answer: C

Rationale: Step-by-step rationale: 1. The seminal vesicle secretes a fluid eliminated in the ejaculatory ducts. 2. This fluid provides nutrients and energy for the sperm. 3. It also helps to neutralize the acidic environment of the male urethra. 4. The fluid from the seminal vesicle combines with sperm to form semen for ejaculation. Summary: A: The seminal vesicle does not secrete androgenic hormones. B: Sperm cells are not secreted by the seminal vesicle. D: The seminal vesicle's fluid does not transport sperm cells; it provides support and nourishment for them.

Correct Answer: A

Rationale: The correct answer is A: prostate. Testosterone is primarily secreted by the testicular interstitial cells (Leydig cells) in the testes. The seminiferous tubules are responsible for spermatogenesis, not testosterone secretion. Straight tubules are involved in transporting sperm. The prostate gland produces prostatic fluid, not testosterone. Therefore, the prostate is not a structure that secretes testosterone.