Human reproduction practice · Mixed difficulty

The correct answer is A (In seminal vesicle) because sperms are stored and further matured in the seminal vesicle.

Option C (Dogs) is correct because the gestation period for both cats and dogs is approximately 63 days (around 9 weeks).

Option D (All the above) is correct because mammary glands are a characteristic feature of mammals, and all the listed animals (Pteropus, Balaenoptera, Ornithorhynchus) are mammals.

Option B ($20^{\text {th }}$ day) is correct because ovulation typically occurs 14 days before the start of the next menstrual period. With a 34-day cycle, ovulation would occur around day 20.

Option B (44) is correct because human primary spermatocytes have 46 chromosomes, including 2 sex chromosomes and 44 autosomes.

Option C (Androgens) is correct because androgens, particularly testosterone, are the primary hormones responsible for maintaining the function of male accessory ducts and glands.

Option A (A-Chorion; B-Placenta) is correct because the chorion completely surrounds the embryo and contributes to the formation of the placenta.

Option C (Gametogenesis $\to$ Insemination $\to$ Fertilization $\to$ Implantation $\to$ Gestation) is correct because it represents the correct order of events in reproduction.

Option B (Size of blastomeres) is correct because during cleavage, the size of blastomeres decreases as the zygote divides into smaller and smaller cells, while the number of blastomeres, nuclear-cytoplasmic ratio, and DNA content increase.

Option C is correct because menstruation is triggered by an abrupt decline in the amount of progesterone and estrogen, hormones secreted by the ovary.

Option D (A- antrum, B- secondary follicle, C-tertiary follicle) is correct because the antrum is a fluid-filled cavity characteristic of the tertiary follicle.

Option A (The fertilized egg is placed in the womb of the mother where the gastrula period is completed) is correct because in IVF, the fertilized egg is implanted into the uterus for further development.

Option A (Head) is correct because the head of the sperm, containing the nucleus with genetic material, enters the ovum during fertilization.

Option B (Development of corpus luteum) is correct because the corpus luteum develops from the Graafian follicle after ovulation, which is stimulated by LH. FSH alone cannot cause corpus luteum development, especially without the anterior pituitary.

Option B (Primary oocyte within primary follicle) is correct because the primary oocyte begins meiosis I within the primary follicle, but the process is arrested at prophase I until puberty.

Option B is correct because capacitation of sperm occurs in the female genital tract, enabling it to fertilize the egg.

Option C (Both (1) and (2)) is correct because the enlarged end of the penis, called the glans penis, is covered by a retractable fold of skin known as both the foreskin and the prepuce.

Option B (Spermatogenesis) is correct because the lower temperature in the scrotal sac is optimal for spermatogenesis.

Option A (Organs) is correct because organogenesis is the process of organ formation during embryonic development.

Option C (Theca externa and theca interna) is correct because the Graafian follicle, a mature ovarian follicle, is characterized by having theca externa and theca interna layers surrounding it.

Option B (A-200, B-300, C-60%, D-40%) is correct because a healthy human male ejaculate contains 200-300 million sperm, with at least 60% having normal shape and size and 40% showing vigorous motility.

Option B (During pregnancy) is correct because hCG and hPL are hormones specifically produced by the placenta during pregnancy.

Option C (During follicular phase of menstrual cycle) is correct because the primary oocyte completes meiosis I within the developing follicle during the follicular phase.

Option C (Both (1) and (2)) is correct because the ejaculatory duct receives sperm from the vas deferens and secretions from the seminal vesicles before emptying into the urethra.

Option C (Epididymis, Abdomen, urinary bladder) is correct because the epididymis leads to the vas deferens, which ascends to the abdomen and loops over the urinary bladder.

Option B (Labia majora) is correct because the labia majora in females are homologous to the scrotum in males, both originating from the same embryonic tissue.

Option C (A- Primary spermatocytes, B- Secondary spermatocytes, C-Spermatozoa) is correct because it represents the correct sequence of cell types during spermatogenesis.

Option B (Vas deferens Ejaculatory duct) is correct because the vas deferens receives a duct from the seminal vesicle and then opens into the urethra as the ejaculatory duct.

Option D (Vas deferens) is correct because the vas deferens is a structure specific to the male reproductive system.

Option B (250) is correct because each human testis has approximately 250 compartments called testicular lobules.