Which of the following is produced by the trophoblast cells during the first 3 weeks of pregnancy?

Correct Answer: D

Rationale: The correct answer is D: Human chorionic gonadotropin (hCG). During the first 3 weeks of pregnancy, trophoblast cells produce hCG, which is crucial for maintaining the corpus luteum and ensuring the production of progesterone to support the early pregnancy. hCG is also the hormone detected in pregnancy tests. Rationale: A: Estrogen is mainly produced by the ovaries, not trophoblast cells in the early stages of pregnancy. B: Luteinizing hormone is produced by the pituitary gland to trigger ovulation, not by trophoblast cells. C: Oxytocin is produced by the hypothalamus and released by the pituitary gland during labor and breastfeeding, not by trophoblast cells in the early stages of pregnancy.

Correct Answer: A

Rationale: The correct answer is A: Seminal vesicles. These glands produce fructose, a sugar in semen that provides energy for sperm. Seminal vesicles are located near the base of the bladder and are responsible for producing a significant portion of the fluid in semen. The other choices are incorrect because the bulbourethral gland produces a clear lubricating fluid, the prostate produces a milky fluid that helps with sperm motility and viability, and the epididymis is a coiled tube where sperm mature and are stored, but it does not produce fructose.

Correct Answer: A

Rationale: The correct answer is A: Seminiferous tubules. Sperm production occurs in the seminiferous tubules of the testis through a process called spermatogenesis. This is where germ cells develop into mature spermatozoa. The other choices are incorrect: B: Ejaculatory duct is where sperm and seminal fluid mix before ejaculation, C: Interstitial cells produce testosterone, and D: Rete testis is a network of tubules where sperm travel after being produced in the seminiferous tubules.

Correct Answer: D

Rationale: The correct answer is D: ovulation. This process involves the release of a mature egg (secondary oocyte) from the ovarian follicle. During ovulation, the egg is released into the fallopian tube, where it can potentially be fertilized by sperm. A: emission - Incorrect. This term typically refers to the discharge of semen from the male reproductive system. B: menses - Incorrect. Menses refers to the shedding of the uterine lining during menstruation, not the release of an egg from the ovary. C: fertilization - Incorrect. Fertilization is the process of the sperm uniting with the egg, which occurs in the fallopian tube after ovulation.

Correct Answer: D

Rationale: The correct answer is D: corpus luteum. Human chorionic gonadotropin (hCG) is produced by the developing placenta during pregnancy. This hormone helps maintain the corpus luteum, which in turn produces progesterone to support the pregnancy. The fluid produced by the corpus luteum helps activate sperm for fertilization. Choices A, B, and C are incorrect as they are not directly involved in the production of hCG or the activation of sperm.