Which hormone thickens the lining of the uterus?

Correct Answer: B

Rationale: The correct answer is B: estrogen. Estrogen is responsible for thickening the lining of the uterus during the menstrual cycle in preparation for implantation of a fertilized egg. Follicle-stimulating hormone (FSH) stimulates the growth of ovarian follicles. Luteinizing hormone (LH) triggers ovulation. Progesterone helps maintain the uterine lining during the second half of the menstrual cycle. Estrogen plays a key role in the initial thickening of the uterine lining, making it the correct choice.

Correct Answer: C

Rationale: The correct answer is C: Spermatogonia. Spermatogonia are the male germ cells that undergo mitosis to produce more spermatogonia or differentiate into primary spermatocytes, which eventually develop into spermatozoa through meiosis. Sertoli cells (A) and Sustentacular cells (B) are somatic cells within the testes that support and nourish developing sperm cells, but they do not give rise to spermatozoa. Chief cells (D) are typically found in the stomach and are responsible for producing pepsinogen, unrelated to sperm production.

Correct Answer: A

Rationale: The correct answer is A: Labia majora. The labia majora are located anterior to the vagina and urethral openings, providing protection and support. The labia minora are internal to the labia majora. The mons pubis is the rounded mass of fatty tissue located over the pubic symphysis. Cervical sphincter is not a relevant anatomical structure in this context. Therefore, the labia majora is the correct choice based on its anatomical location and function.

Correct Answer: B

Rationale: The correct answer is B: Mesonephric (Wolffian) ducts. The male reproductive system arises from the mesonephric ducts, which develop into structures like the epididymis, vas deferens, and seminal vesicles. The mesonephric ducts are responsible for transporting sperm from the testes to the urethra. The other choices are incorrect because A (Paramesonephric ducts) develop into the female reproductive system, C (FSH) is a hormone involved in the regulation of reproductive processes but does not directly give rise to the male reproductive system, and D (aldosterone) is a hormone involved in electrolyte balance and has no role in male reproductive system development.

Correct Answer: D

Rationale: The correct answer is D: Nipple. The mammary papilla refers to the nipple, the protruding part of the breast where milk is released during breastfeeding. It is the anatomical structure that connects the lactiferous ducts to the outside of the body. The other choices are incorrect because: A: Areola is the darker area surrounding the nipple. B: Lactiferous duct is the tube that carries milk from the mammary glands to the nipple. C: Sinuses are not directly related to the mammary papilla.