What is the content of the acrosome?

Correct Answer: C

Rationale: The correct answer is C: Digestive enzymes. The acrosome is a structure found in sperm cells that contains enzymes used to penetrate the egg during fertilization. Choice A (Lipids) and Choice B (Hormones) are incorrect as the primary content of the acrosome is digestive enzymes, not lipids or hormones. Choice D (None of the above) is incorrect as the acrosome does contain a specific substance, which are digestive enzymes.

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.

Correct Answer: D

Rationale: The secretory phase is not considered a distinct phase of the menstrual cycle; it is actually part of the luteal phase. During the luteal phase, the endometrium thickens due to progesterone secretion, preparing for implantation. The follicular phase is characterized by follicle development, leading to ovulation. The ovulatory phase is when the mature egg is released from the ovary. Therefore, the secretory phase is the correct answer as it is not a standalone phase but a part of the luteal phase.