Which cells secrete testosterone?

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: A

Rationale: The female reproductive system arises from Paramesonephric (Mullerian) ducts. These ducts develop into the fallopian tubes, uterus, and upper part of the vagina. Initially present in both sexes, in females, they persist and differentiate into the female reproductive organs under the influence of estrogen. Mesonephric (Wolffian) ducts develop into male reproductive structures. Aldosterone is a hormone related to electrolyte balance and has no direct role in female reproductive system development. FSH (Follicle-Stimulating Hormone) is a pituitary hormone that stimulates ovarian follicle development but does not play a role in the initial development of the female reproductive system.

Correct Answer: A

Rationale: Rationale: A chancre is a painless ulcer that is characteristic of primary syphilis infection. It usually appears on the external genitalia as a result of Treponema pallidum infection. This is distinct from the other conditions listed: Gonorrhea presents with urethritis and discharge, Trichomoniasis with vaginal discharge and irritation, and Herpes genitalis with painful vesicles or ulcers. Syphilis is the only condition among the choices that typically presents with a chancre on the external genitalia.

Correct Answer: D

Rationale: The correct answer is D: parturition. Parturition refers to the process of giving birth. It involves the series of events that lead to the expulsion of the fetus from the mother's womb. Lactation (choice A) is the production of milk by the mammary glands after birth. Gestation (choice B) is the period of development of the fetus in the womb. Micturition (choice C) is the process of urination and is not related to childbirth. Therefore, the term that specifically describes the process of giving birth is parturition.

Correct Answer: B

Rationale: The correct answer is B: Amenorrhea. Amenorrhea refers to the absence of menstruation, which can be caused by various factors such as hormonal imbalances, stress, pregnancy, or medical conditions. Rhinorrhea (A) is the medical term for a runny nose, unrelated to menstruation. Menorrhagia (C) is excessive menstrual bleeding, the opposite of absence of menstruation. Leucorrhea (D) is a vaginal discharge, not related to the absence of menstruation. Therefore, B is the correct answer as it directly addresses the absence of menstruation.