Cryptorchidism is a condition where _________.

Correct Answer: B

Rationale: Cryptorchidism is a condition where one or both testes fail to descend into the scrotum. This means that the testes do not properly move from the abdomen into the scrotum during fetal development. Choice A is incorrect because the issue is not about development but descent. Choice C is incorrect as it implies that the testes were never formed, which is not the case in cryptorchidism. Choice D is incorrect as cryptorchidism does involve the testes but rather their descent into the scrotum.

Correct Answer: A

Rationale: The correct answer is A: Placenta. The placenta is a temporary organ that connects a mammalian mother to its foetus. It plays a crucial role in facilitating the exchange of nutrients, oxygen, and waste between the mother and the developing baby. Choice B, Chorion, is incorrect as it is a part of the fetal membrane but not the organ that connects the mother to the fetus. Choice C, Endometrium, is incorrect as it is the lining of the uterus where implantation occurs but is not the organ responsible for connecting the mother to the fetus. Choice D, None of the above, is incorrect as the placenta specifically fits the description provided in the question.

Correct Answer: D

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: C

Rationale: Oligomenorrhea is defined as a menstrual cycle longer than 35 days. A cycle of 28 days (Choice A) is within the normal range, and not considered oligomenorrhea. Similarly, 30 days (Choice B) and 40 days (Choice D) are also within the normal range. The correct definition of oligomenorrhea specifically refers to cycles longer than 35 days, making Choice C the correct answer.

Correct Answer: B

Rationale: The correct answer is B: The corpus luteum produces progesterone to maintain the endometrium during the menstrual cycle. This hormone helps prepare the uterine lining for implantation in case fertilization occurs. Choice A is incorrect because estrogen is mainly produced by the developing follicles in the ovaries. Choice C is incorrect as testosterone is produced in smaller amounts by the ovaries and adrenal glands but does not play a significant role in maintaining the endometrium. Choice D is incorrect as the corpus luteum plays a crucial role in producing progesterone to support the endometrium.