What is the purpose of the zona pellucida during fertilization?

Correct Answer: B

Rationale: The purpose of the zona pellucida during fertilization is to protect the egg during early development. It acts as a protective barrier around the egg, preventing polyspermy and providing structural support for the developing embryo. This choice is correct because the zona pellucida serves as a crucial protective layer for the egg in the initial stages post-fertilization. - A: Incorrect because the zona pellucida actually allows sperm entry into the egg. - C: Incorrect because the zona pellucida does not specifically facilitate sperm entry; its primary function is protection. - D: Incorrect because the zona pellucida is not directly involved in egg implantation, but rather in early embryonic development.

Correct Answer: D

Rationale: The correct answer is D: LH (luteinizing hormone). LH is responsible for stimulating the release of eggs from the ovaries during ovulation. This hormone triggers the final maturation and release of the egg from the ovarian follicle. Estrogen and progesterone play roles in the menstrual cycle but do not directly stimulate egg release. FSH (follicle-stimulating hormone) is involved in follicle development but does not trigger egg release. Therefore, LH is the correct choice for its specific role in ovulation.

Correct Answer: B

Rationale: The correct answer is B: Secrete seminal fluid. Seminal vesicles produce and secrete seminal fluid, which is a major component of semen. This fluid provides nutrients and protection for sperm, aiding in their motility and survival. Storing sperm (choice A) is primarily the function of the epididymis. Testosterone production (choice C) occurs in the testes, while sperm production (choice D) takes place in the testes as well. Therefore, choice B is the correct answer as seminal vesicles specifically contribute to the production of seminal fluid.

Correct Answer: D

Rationale: The primary function of the uterine tubes (fallopian tubes) is to transport eggs from the ovary to the uterus for potential fertilization. This process involves capturing an egg released from the ovary, providing a site for fertilization by sperm, and conducting the fertilized egg (zygote) to the uterus for implantation. Choice A is incorrect because sperm are not transported through the fallopian tubes. Choice B is incorrect as the fallopian tubes do not store eggs but rather facilitate their movement. Choice C is incorrect as fertilization occurs in the fallopian tubes but they do not actively support the process.

Correct Answer: B

Rationale: The correct answer is B: Stimulate uterine contractions. Oxytocin is a hormone that plays a key role in initiating and maintaining labor by stimulating uterine contractions. It acts on the smooth muscles of the uterus to promote the rhythmic contractions necessary for childbirth. Oxytocin also helps with the ejection of milk during breastfeeding but its primary role in childbirth is to stimulate uterine contractions. Incorrect choices: A: Inhibit uterine contractions - This is incorrect as oxytocin actually stimulates, not inhibits, uterine contractions. C: Increase milk production - While oxytocin does play a role in milk ejection during breastfeeding, its primary role in childbirth is to stimulate uterine contractions. D: Prepare the cervix for dilation - While oxytocin may contribute to cervical dilation during labor, its primary role is in stimulating uterine contractions.