Human Reproduction

Statement I is true: the presence or absence of the hymen is not a reliable indicator of virginity or sexual experience. Statement II is false: the hymen is often torn during the first coitus, but it can also be broken by a sudden fall or jolt, insertion of a tampon, or active sports such as horse-riding and cycling; in some women it persists even after coitus. So Statement I is true but Statement II is false.

Assertion: In males, FSH acts on the Sertoli cells (not Leydig cells) and stimulates secretion of factors that help in spermiogenesis; LH acts on the Leydig cells. So the Assertion is false. Reason: Growing ovarian follicles secrete estrogen in females, while interstitial (Leydig) cells secrete androgens in males – true. So A is false but R is true.

Breast-feeding during the initial period of infant growth is recommended by doctors for bringing up a healthy baby – Assertion is true. Colostrum, the yellowish fluid secreted during the initial days of lactation, contains abundant antibodies (IgA) essential to develop resistance in the new-born baby – Reason is true and correctly explains the Assertion. So both A and R are correct and R is the correct explanation of A.

The fallopian tube (oviduct) consists of the infundibulum (part closer to the ovary), ampulla (wider part) and isthmus (last narrow part that links to the uterus). The uterine fundus is the upper dome-shaped part of the uterus, above the openings of the fallopian tubes, so it is not a part of the fallopian tube.

GnRH from the hypothalamus acts on the anterior pituitary to release LH and FSH, so (A) = FSH.
LH acts on the Leydig cells and stimulates synthesis and secretion of androgens, so (B) = Leydig cells.
FSH acts on the Sertoli cells and stimulates secretion of factors that help in spermiogenesis, so (C) = Sertoli cells and (D) = spermiogenesis.
So the correct option is FSH, Leydig cells, Sertoli cells, spermiogenesis.