The initiation of puberty and menses in a female, involves increased levels of _____.

Correct Answer: C

Rationale: The correct answer is C: estrogen. During puberty in females, the hypothalamus signals the pituitary gland to release hormones, leading to increased estrogen levels. Estrogen plays a key role in the development of secondary sexual characteristics and the onset of menstruation. FSH and LH are also involved in the menstrual cycle but do not directly initiate puberty. Progesterone is mainly involved in the menstrual cycle's later stages, not the initiation of puberty.

Correct Answer: A

Rationale: Progesterone is the correct answer because it is responsible for preparing the uterus for potential implantation by increasing glycogen levels. Progesterone promotes the growth of blood vessels and glands in the uterus, leading to increased glycogen production. FSH and LH are involved in the menstrual cycle and ovulation but do not directly impact glycogen levels in the uterus. Estrogen plays a role in the growth and thickening of the endometrial lining but does not specifically stimulate glycogen production.

Correct Answer: A

Rationale: The correct answer is A: Acrosome. The acrosome is an organelle in the head of the sperm that contains enzymes which help the sperm penetrate the outer layer of the ovum during fertilization. It plays a crucial role in the fertilization process. Explanation of other choices: B: Zona pellucida is the outer membrane of the ovum that the sperm needs to penetrate, not an organelle within the sperm itself. C: Megalis is not a relevant organelle involved in fertilization. D: None of the above is incorrect as the acrosome is the specific organelle that aids in sperm penetration of the ovum.

Correct Answer: C

Rationale: Step-by-step rationale: 1. Leydig cells are located in the testes and are responsible for secreting testosterone. 2. Testosterone is a male sex hormone crucial for regulating various functions in the body. 3. Sertoli cells provide support for sperm development, not testosterone secretion. 4. Spermatogenic cells are involved in sperm production, not testosterone secretion. 5. Oogonia are female germ cells, not involved in testosterone secretion. Summary: Choice C (Leydig cells) is correct because they are the specific cells in the testes responsible for secreting testosterone. Choices A, B, and D are incorrect as they are associated with other functions related to reproduction and are not involved in testosterone secretion.

Correct Answer: B

Rationale: The paraurethral (Skene's) glands are responsible for secreting mucus to facilitate lubrication during sexual arousal. This mucus aids in lubricating the urethra and providing moisture for sexual intercourse. Estrogen (Choice A) is a hormone produced by the ovaries and not directly related to the function of Skene's glands. Testosterone (Choice C) and androgens (Choice D) are male sex hormones and are not involved in the secretion of mucus by Skene's glands. Therefore, the correct answer is B, mucus, as it aligns with the known function of the paraurethral glands.