Human reproduction practice · Medium

Option B (d only) is correct because only statement (d) is true for oogenesis but not for spermatogenesis. Oogenesis results in unequal cells (ovum and polar bodies), while spermatogenesis results in equal cells (spermatids).

Option D (All of the above) is correct because in human beings, the chorion and amnion are well developed, the allantois and yolk sac are less developed, and the yolk cell has very little yolk.

Option A (Prophase-I) is correct because primary oocytes are arrested in prophase I of meiosis at the time of birth.

Option D (Both (1) and (2)) is correct because during the menstrual phase, both progesterone and LH levels decrease significantly.

Option C (Lack of progesterone) is correct because progesterone maintains the endometrium, and its decline leads to the breakdown and shedding of the uterine lining during menstruation.

Option A (A-primary sex organs; B-secondary sex organs) is correct because primary sex organs produce gametes and secondary sex organs do not.

Option A (I and IV) is correct because testosterone influences male secondary sexual characteristics, and the placenta secretes estrogen.

Option B (Ovolysin) is correct because ovolysin (also known as hyaluronidase) is the enzyme present in the sperm acrosome that helps dissolve the egg membrane (zona pellucida).

Option C (If assertion is true but reason is false) is correct because while iodine deficiency can affect menstrual cycles, the reason provided (low estrogen and progesterone) is not the direct cause.

Option A (Endocrine gland) is correct because the placenta secretes hormones like hCG, hPL, estrogen, and progesterone, making it an endocrine gland.

Option C (Primary follicle starts developing) is the correct answer because if fertilization fails, the corpus luteum degenerates, hormone levels decline, and a new cycle begins with the development of a primary follicle.

Option D (Both (a) and (b)) is correct because the first polar body is formed during oogenesis before birth, and the second polar body is formed after birth, during fertilization.

Option C (57.6 million) is correct because for normal fertility, 60% of sperms must have normal shape, size, and vigorous motility. With a sperm count of 80 million/mL in 3 mL, the total sperm count is 240 million. 60% of 240 million is 144 million. However, the question asks for the number of sperms with normal shape, size and vigorous motility per ejaculate of 3ml semen, and the correct calculation is 240 million * 0.6 = 144 million. The question states that 80 million sperms per ml is the count for normal fertility, and 60% of the total sperms must have normal shape, size and vigorous motility. Therefore, 80 million/ml * 3 ml = 240 million sperms. 60% of 240 million = 144 million * 0.4 = 57.6 million.

Option C (Oxytocin) is correct because oxytocin is secreted by the hypothalamus and released by the posterior pituitary gland, not the placenta.

Option B (Be sterile) is correct because FSH is essential for spermatogenesis, and without it, the boy will be unable to produce sperm.

Option B (Ovulation) is correct because the event labelled A in the figure (not provided, but assumed to be the LH surge peak) corresponds to ovulation.

Option A (Insemination) is correct because insemination refers to the release of semen into the vagina during sexual intercourse.

Option B (Bartholin’s glands) is correct because Cowper's glands in males are analogous to Bartholin's glands in females, both providing lubrication.

Option C (Vasa efferentia) is correct because the vasa efferentia primarily transport sperm from the testes to the epididymis, while the other structures contribute to sperm maturation and motility.

Option D (Tail – contain numerous mitochondria, which produce energy for movement of tail) is mismatched because the midpiece, not the tail, contains the mitochondria that provide energy for the tail's movement.

Option B (B only) is correct because sperm formation can continue even in old men, while the other statements are incorrect.

Option D (Both (a) and (b)) is correct because the second meiotic division in the ovum results in the formation of a haploid ovum and a second polar body.

Option B (Infundibulum) is correct because the infundibulum is the funnel-shaped part of the fallopian tube closest to the ovary.

Option B is the correct answer because chorionic villi are finger-like projections on the trophoblast surrounded by uterine tissue and maternal blood.

Option B (Vas deferens) is correct because the cauda epididymis, the tail of the epididymis, leads directly into the vas deferens.

Option D (  Assertion is false andReason is correct) is correct because spermatogenesis occurs in the seminiferous tubules, but testosterone is secreted by Leydig cells, not Sertoli cells.

Option B (Either zygote or early embryo upto 8 celled stage) is correct because in ZIFT (Zygote Intrafallopian Transfer), either the zygote or an early embryo (up to 8 cells) is transferred into the fallopian tube.

Option A (Graafian follicle) is correct because after ovulation, the remaining part of the Graafian follicle transforms into the corpus luteum, which acts as an endocrine gland.

Option A (Polar bodies) is correct because during oogenesis, the primary oocyte undergoes meiosis, resulting in a large secondary oocyte and a small polar body, which contains very little cytoplasm.

Option D (Help in the collection of the ovum after ovulation) is correct because fimbriae are finger-like projections that sweep the ovulated ovum into the fallopian tube.