When menstruation ends in middle age:

Correct Answer: A

Rationale: The correct answer is A: Menopause. Menopause refers to the natural cessation of menstruation in middle-aged women, typically around the age of 45-55. It occurs due to declining levels of estrogen and progesterone hormones, leading to the end of reproductive capacity. Gestation (B) refers to pregnancy, not the cessation of menstruation. Implantation (C) is the process of a fertilized egg attaching to the uterus, not related to the end of menstruation. Uterus (D) is an organ involved in menstruation but does not specifically refer to the cessation of menstruation in middle age.

Correct Answer: C

Rationale: The correct answer is C because testicular lobules are indeed made up of 2-3 convoluted seminiferous tubules where spermatogenesis occurs. This process of sperm production takes place within the seminiferous tubules, making option C the most accurate description of the testicular lobules. A is incorrect because the testicular lobules are not delineated by connective septa separated from the tunica albuginea. B is also incorrect as interstitial tissue is found between the lobules, not separating each individual lobule. D is incorrect as spermatogenesis specifically occurs within the seminiferous tubules, not at the level of the testicular lobules.

Correct Answer: D

Rationale: The correct answer is D: prostate. The prostate is an internal male reproductive organ located below the bladder. Step-by-step rationale: A - The penis is an external male genital organ. B - Seminal ducts are also known as vas deferens and are part of the male reproductive system. C - The corpus spongiosum is a spongy tissue structure found in the penis. Thus, the prostate is the only internal organ listed, making it the correct answer.

Correct Answer: A

Rationale: Step-by-step rationale: 1. The prostate gland secretes a milky fluid that constitutes a major portion of semen. 2. This prostatic fluid contains enzymes, citric acid, and zinc, which nourish and protect sperm. 3. Seminal vesicles also contribute to semen production, but mainly by providing fructose for sperm energy. 4. The scrotum houses the testes but does not directly contribute fluids to semen. 5. The epididymal duct is a site for sperm maturation and storage but does not produce semen fluids. Summary: Choice A is correct because the prostate gland secretes a significant portion of semen. Choices B, C, and D are incorrect because they do not directly contribute fluids to semen production.

Correct Answer: C

Rationale: The correct answer is C: primordial. Ovarian follicles go through several stages of development. Primordial follicles are the earliest stage, containing primary oocytes surrounded by a single layer of squamous cells. This stage represents the resting pool of follicles. Secondary follicles come next, with primary oocytes surrounded by multiple layers of granulosa cells. Tertiary (de Graaf) follicles are the most advanced stage, containing a fluid-filled antrum and a mature oocyte. Evolutionary is not a recognized stage in ovarian follicle development. Secondary is incorrect as it comes after primordial, and tertiary is incorrect as it is not the earliest stage.