Which structure will actually become the fetus?

Correct Answer: C

Rationale: The correct answer is C: inner cell mass. After fertilization, the zygote undergoes several cell divisions to form a hollow ball of cells called a blastocyst. Within the blastocyst, the inner cell mass contains cells that will develop into the fetus. The morula is an earlier stage consisting of a solid ball of cells. The zygote is the initial cell formed from the fusion of egg and sperm, but it does not directly become the fetus. Therefore, the inner cell mass is the structure that will actually develop into the fetus, making it the correct answer.

Correct Answer: C

Rationale: The correct answer is C: Seminal vesicles. These glands are located posterior to the bladder and anterior to the rectum. They secrete an alkaline fluid rich in fructose, which nourishes and supports sperm viability. The other choices are incorrect because: A) The prostate is located below the bladder and surrounds the urethra, secreting a milky fluid; B) The bulbourethral gland is located below the prostate and secretes a clear, viscous fluid; D) The spongy urethra is a part of the male urethra that runs through the penis, responsible for transporting urine and semen.

Correct Answer: C

Rationale: The correct answer is C: Proliferative phase. During this phase, the endometrium thickens in preparation for a potential implantation of a fertilized egg. This phase occurs after the menstrual phase and before ovulation, marking the time when the ovarian follicles are developing under the influence of FSH. The other choices are incorrect because the menstrual phase (A) refers to the shedding of the endometrium, the preovulatory phase (B) occurs just before ovulation, and the follicular phase (D) includes both the menstrual and preovulatory phases.

Correct Answer: A

Rationale: The correct answer is A: dihydrotestosterone (DHT). DHT is a potent form of testosterone responsible for male sexual development, including the formation of the urethra, prostate, and external genitals. It binds to androgen receptors in target tissues, promoting their growth and differentiation. FSH (Choice B) is follicle-stimulating hormone, which primarily regulates sperm production in males. Progesterone (Choice C) is a female sex hormone involved in the menstrual cycle and pregnancy. Estrogen (Choice D) is a female sex hormone responsible for female reproductive development. Thus, A is the correct answer as it specifically pertains to male sexual differentiation.

Correct Answer: D

Rationale: The correct answer is D: Fimbriae. Fimbriae are the fingerlike projections at the end of the fallopian tubes that help capture the released egg from the ovary. They create a sweeping motion to guide the egg into the tube for fertilization. Cilia (A) are hair-like projections that help with movement, but they are not specific to the fallopian tubes. Papillae (B) are small, raised projections found in various organs, not in the fallopian tubes. Flagellae (C) are whip-like structures used for movement in some cells, not found in the fallopian tubes. In summary, fimbriae are specifically designed to capture and guide the egg, making them the correct choice.