Estrogen

Correct Answer: D

Rationale: Estrogen is known to stimulate ductal proliferation in the breast tissue as part of its role in breast development and maintenance. This is crucial for preparing the breast for potential pregnancy and lactation. The other choices are incorrect because estrogen does not directly cause cystic changes in the vagina, alter the pH of cervical mucus to become more alkaline, or specifically facilitate the growth of ovarian follicles. Estrogen plays a role in ovarian follicle development, but its main function in this context is to stimulate the growth and maturation of the follicles, not just facilitate their growth.

Correct Answer: B

Rationale: The correct answer is B: seminiferous tubules. Testicular cancer arises from the cells within the seminiferous tubules where sperm production occurs. These tubules are the most common site for testicular cancer to develop. The other choices are incorrect because testicular cancer typically does not originate from the scrotal sac (A), epididymis (C), or interstitial cells (D). The scrotal sac contains the testicles but does not produce cancer, the epididymis is a different structure involved in sperm maturation, and interstitial cells produce hormones rather than sperm.

Correct Answer: D

Rationale: The correct answer is D: blood leaves erectile tissue. During penile erection, blood flows into the erectile tissue, causing the penis to become erect. Parasympathetic stimulation and arterial dilation are essential for promoting blood flow into the penis, while venous compression helps to trap blood within the erectile tissue, sustaining the erection. However, if blood were to leave the erectile tissue, it would result in a loss of erection. Therefore, choice D is not compatible with penile erection.

Correct Answer: A

Rationale: The corona radiata cells appear at birth because they are a crucial part of the ovum and are present as soon as the ovum is released from the ovary. The other choices are incorrect because corona radiata cells are not formed at 12, 28, or 1 day after birth. They are specifically associated with the ovum and its release during ovulation, making option A the most accurate.

Correct Answer: D

Rationale: The correct answer is D: estrogen. Estrogen is the hormone that stimulates the growth and development of secondary female sex organs like the breasts, uterus, and fallopian tubes. It plays a crucial role in regulating the menstrual cycle and preparing the body for pregnancy. FSH and LH are hormones released by the pituitary gland that primarily regulate the ovarian cycle, while GnRH is a hormone released by the hypothalamus to stimulate the pituitary gland to release FSH and LH. Estrogen, being a primary female sex hormone, directly influences the development and function of secondary sex organs in females.