NEET Biology Human Reproduction MCQs Set 27

Answer: (a) Primary oocyte

Explanation:
1. The zona pellucida is a glycoprotein layer laid down around the growing primary oocyte as the follicle develops.
2. Oogonia are only the dividing germ cells of the foetal ovary, and the ovary is an organ, so neither forms the layer.

Answer: (d) Second polar body

Explanation:
1. A mature Graafian follicle holds the secondary oocyte, surrounded by corona radiata and granulosa cells.
2. The second polar body appears only after a sperm enters the secondary oocyte, so it is not present at this stage.

Answer: (b) Vas deferens and vasa efferentia

Explanation:
1. Sperms pass from seminiferous tubules to rete testis, then vasa efferentia, then epididymis, then vas deferens.
2. So the epididymis lies between the vasa efferentia and the vas deferens.

Answer: (b) A - 200-300, B - 60, C - 40

Explanation:
1. A normal ejaculate contains 200-300 million sperms.
2. Fertility requires at least 60 percent normal sperms and at least 40 percent vigorously motile sperms.

Answer: (c) Prostate gland

Explanation:
1. Semen clots after ejaculation and is then liquefied by prostatic enzymes.
2. The seminal vesicle adds fructose and the Cowper's gland adds a lubricating fluid.

Answer: (c) Three

Explanation:
1. Statements (i) and (ii) are correct.
2. (iii) is wrong because the new membrane is the zona pellucida. (iv) is wrong because the LH surge causes rupture of the follicle and ovulation. (v) is wrong because the tubule is lined by spermatogonia (male germ cells) and Sertoli cells, not by spermatozoa.
3. Three statements are incorrect.

Answer: (a) Each ovary at puberty

Explanation:
1. A female is born with about 2 million follicles in each ovary, and most degenerate in childhood. At puberty only 60000-80000 primary follicles remain in each ovary.

Answer: (c) Spermiogenesis

Explanation:
1. Spermiogenesis is the transformation of the round spermatid into a sperm with head, middle piece and tail.
2. Spermiation is the later release of sperms from the Sertoli cells into the tubule lumen.

Answer: (a) a, c and e

Explanation:
1. Androgens are made by Leydig cells, so (a) is wrong.
2. Leydig cells lie between seminiferous tubules in the testis, so (c) is wrong.
3. Oogenesis occurs in the follicle, not the corpus luteum, so (e) is wrong. The others are correct.

Answer: (d) Mammary duct

Explanation:
1. Alveoli open into mammary tubules.
2. The tubules of a lobe join to form a mammary duct, and several ducts join into a mammary ampulla that connects to the lactiferous duct.

Answer: (c) Primary follicle

Explanation:
1. Primary oocyte plus one layer of granulosa cells is a primary follicle.
2. Later the follicle gains more layers (secondary) and an antrum (tertiary) before becoming the Graafian follicle.

Answer: (b) Cervix

Explanation:
1. The uterus has a broad fundus, a body and a narrow lower end called the cervix, which opens into the vagina.

Answer: (b) Golgi body

Explanation:
1. The Golgi apparatus of the spermatid forms the acrosomal cap, a lysosome-like sac of enzymes over the head.

Answer: (c) A - endometrium, B - myometrium

Explanation:
1. The endometrium thickens and sheds in each cycle.
2. The myometrium is the thick smooth muscle layer that contracts in labour.

Answer: (b) Spermatogonia, primary spermatocyte, secondary spermatocytes, spermatid, spermatozoa

Explanation:
1. A spermatogonium grows into a primary spermatocyte, which divides by meiosis I into secondary spermatocytes.
2. Meiosis II gives spermatids, and spermiogenesis turns them into spermatozoa.

Answer: (d) Inhibin

Explanation:
1. Sertoli cells make inhibin, which suppresses FSH release. Testosterone comes from Leydig cells, and FSH and LH come from the pituitary.

Answer: (d) FSH

Explanation:
1. FSH acts on Sertoli cells, which then secrete factors that support spermiogenesis. LH acts on Leydig cells.

Answer: (a) Female genital tract

Explanation:
1. Sperms become fully able to fertilise only after spending some time in the female genital tract, where secretions remove coating proteins from the sperm surface.

Answer: (d) Mons pubis

Explanation:
1. The mons pubis is the fatty cushion over the pubic bone. The labia majora are the fleshy folds that surround the vaginal opening.

Answer: (d) a, b, c, d and e

Explanation:
1. The external genitalia are the mons pubis, labia majora, labia minora, hymen and clitoris.
2. The vagina is an internal accessory duct and the rete testis belongs to the male system.

Answer: (c) Acrosome and nucleus

Explanation:
1. The head has the haploid nucleus covered by the acrosome cap. Mitochondria are in the middle piece.

Answer: (a) Urethra

Explanation:
1. The urethra carries both urine and semen, so it is the common passage of both systems.

Answer: (b) It is produced by granulosa cells in the ovary and inhibits the secretion of FSH

Explanation:
1. Inhibin is made by granulosa cells in females (and Sertoli cells in males). It specifically suppresses FSH secretion.

Answer: (b) Both FSH and LH attain their peak levels on day 14

Explanation:
1. Around mid-cycle (day 14) there is a surge of LH with a smaller rise in FSH, causing ovulation.
2. Progesterone peaks later in the secretory phase, and estrogen peaks just before ovulation.

Answer: (c) (i)=c, (ii)=e, (iii)=a, (iv)=b, (v)=d

Explanation:
1. The heart forms after about one month and limbs and digits by the end of the second month.
2. Most organ systems are present by the end of the first trimester, hair on the head appears in the fifth month and the eyelids separate by the sixth month.

Answer: (a) Sertoli cells

Explanation:
1. FSH acts on the Sertoli cells. LH acts on the Leydig cells.

Answer: (c) Progesterone

Explanation:
1. If the egg is not fertilised the corpus luteum degenerates and progesterone falls. The endometrium can no longer be maintained and is shed as menstrual flow.