Which hormone causes milk ejection during breastfeeding?

Correct Answer: B

Rationale: Oxytocin is the correct answer because it is the hormone responsible for milk ejection during breastfeeding. When a baby suckles, oxytocin is released, causing the muscles around the milk-producing cells to contract and push milk into the ducts. Prolactin, on the other hand, is responsible for milk production but not ejection. Estrogen and progesterone play roles in preparing the breasts for milk production but are not directly involved in milk ejection.

Correct Answer: A

Rationale: The correct answer is A: Sperm maturation and storage. The epididymis is where sperm produced in the testes mature and are stored until ejaculation. It provides a suitable environment for sperm maturation through the absorption of excess fluid and nutrients. It also helps in the development of sperm motility. Choices B and C are incorrect because sperm production occurs in the testes, and testosterone is primarily produced in the testes and adrenal glands. Choice D is incorrect because the transport of sperm to the urethra is mainly facilitated by the vas deferens.

Correct Answer: B

Rationale: The primary function of the testes is to produce sperm, making option B the correct answer. Sperm production occurs in the seminiferous tubules within the testes. Estrogen production primarily occurs in the ovaries, not the testes (eliminating choice A). Storing sperm is mainly the role of the epididymis, not the testes (eliminating choice C). Testosterone secretion is a crucial function of the testes, but it is not the primary function (eliminating choice D). In summary, the testes' primary function is to produce sperm, making it the correct choice.

Correct Answer: C

Rationale: The correct answer is C: LH (Luteinizing Hormone). LH is responsible for triggering ovulation, the release of an egg from the ovary. It surges around mid-cycle to stimulate the mature egg's release. Estrogen and progesterone play roles in the menstrual cycle but do not directly trigger ovulation. FSH (Follicle-Stimulating Hormone) helps in follicle development but does not induce ovulation. Therefore, LH is the hormone specifically responsible for this crucial reproductive process in females.

Correct Answer: A

Rationale: The correct answer is A: Placenta. The placenta is responsible for providing nutrients and oxygen to the developing fetus through the umbilical cord. It acts as a barrier between the mother and the fetus, allowing for the transfer of essential substances while protecting the fetus from harmful substances. The ovary (B) is involved in producing eggs but does not provide nutrients to the fetus. The fallopian tube (C) is where fertilization typically occurs, not nutrient transfer. The cervix (D) is the lower part of the uterus that connects to the vagina and plays a role in childbirth, but it is not responsible for providing nutrients and oxygen to the fetus.