NEET Biology Human Reproduction MCQs Set 37

Answer: (c) mesoderm

Explanation:
1. The gonads (testes and ovaries) develop from the intermediate mesoderm of the embryo.

Teacher's Note:
1. The mesoderm also forms the kidneys and the reproductive ducts.
2. Gonads are mesodermal.

Answer: (c) 2

Explanation:
1. A primary spermatocyte gives two secondary spermatocytes in meiosis I, and each divides in meiosis II to give two spermatids. So one secondary spermatocyte gives 2 sperms.

Teacher's Note:
1. One primary spermatocyte gives 4 sperms.
2. Count each division separately.

Answer: (d) testis and testosterone

Explanation:
1. Leydig (interstitial) cells lie between the seminiferous tubules of the testis and secrete testosterone.

Teacher's Note:
1. Sertoli cells nourish the germ cells.
2. Leydig cells make androgens.

Answer: (b) mitochondria only

Explanation:
1. The middle piece of the sperm is packed with mitochondria, which supply energy for the tail movement.

Teacher's Note:
1. The centrioles lie at the neck.
2. Mitochondria give the sperm energy.

Answer: (b) mature eggs

Explanation:
1. Mature eggs release fertilizins, chemicals that attract sperms of the same species.

Teacher's Note:
1. They bind to antifertilizins on the sperm.
2. Fertilizin attracts sperms.

Answer: (b) one X - chromosome

Explanation:
1. A secondary oocyte is released at ovulation and it carries one X chromosome, since the egg is haploid and all eggs have an X.

Teacher's Note:
1. Sperms may carry X or Y.
2. Eggs always carry X.

Answer: (a) after entry of sperm but before completion of fertilization

Explanation:
1. The secondary oocyte is arrested at metaphase II and completes meiosis II only after the sperm enters. The second polar body is extruded then.

Teacher's Note:
1. Fertilisation is completed after fusion of nuclei.
2. Sperm entry triggers meiosis II.

Answer: (d) Leydig

Explanation:
1. Leydig cells of the testis secrete the male hormone testosterone.

Teacher's Note:
1. Sertoli cells are the nurse cells.
2. Match the cell with the hormone.

Answer: (a) LH

Explanation:
1. A surge of LH in the middle of the cycle triggers ovulation.

Teacher's Note:
1. FSH stimulates the follicle to grow.
2. LH surge means ovulation.

Answer: (c) 14 day

Explanation:
1. In a 28-day cycle, ovulation occurs about the 14th day.

Teacher's Note:
1. Menstruation takes place for the first 5 days.
2. Ovulation is at mid-cycle.

Answer: (a) secondary spermatocyte

Explanation:
1. Meiosis I of the primary spermatocyte gives two haploid secondary spermatocytes.

Teacher's Note:
1. Meiosis II gives spermatids.
2. Primary becomes secondary after meiosis I.

Answer: (b) progesterone

Explanation:
1. The corpus luteum secretes progesterone, which maintains the endometrium.

Teacher's Note:
1. It also makes some estrogen.
2. Corpus luteum means progesterone.

Answer: (d) mammalian females other than primates

Explanation:
1. Mammalian females other than primates show an estrus cycle, with a period of heat. Primates (including humans) show the menstrual cycle.

Teacher's Note:
1. The estrus cycle has no menstruation.
2. Estrus is a non-primate cycle.

Answer: (a) corpus luteum

Explanation:
1. After ovulation the ruptured Graafian follicle changes into the corpus luteum under the effect of LH.

Teacher's Note:
1. The corpus albicans forms later from a degenerated corpus luteum.
2. Follicle to corpus luteum.

Answer: (b) LH

Explanation:
1. LH from the pituitary stimulates the formation of the corpus luteum and the secretion of progesterone.

Teacher's Note:
1. LH is highest at ovulation.
2. LH controls the corpus luteum.

Answer: (c) FSH, LH, estrogen

Explanation:
1. The menstrual cycle is regulated by FSH, LH, estrogen and progesterone, so all of these hormones control it, not only one.

Teacher's Note:
1. The pituitary and the ovary act together.
2. Think of the pituitary-ovary axis.

Answer: (c) Estrogen

Explanation:
1. Estrogen is secreted by the ovary, so removing both ovaries lowers estrogen in the blood.

Teacher's Note:
1. Prolactin and oxytocin are pituitary hormones.
2. Ovary makes estrogen.

Answer: (a) on either side of vagina in humans

Explanation:
1. Bartholin's glands are a pair of glands on either side of the vaginal opening in women.

Teacher's Note:
1. They secrete lubricating mucus.
2. They are the female counterpart of the Cowper gland.

Answer: (d) Progesterone

Explanation:
1. When the corpus luteum degenerates, the progesterone level falls and the endometrium breaks down. This causes menstruation.

Teacher's Note:
1. Progesterone maintains the uterine lining.
2. Withdrawal of progesterone causes menstrual flow.

Answer: (a) Graafian follicle

Explanation:
1. After ovulation the Graafian follicle forms the corpus luteum, which acts as an endocrine gland.

Teacher's Note:
1. It secretes progesterone.
2. The corpus luteum is the remains of the follicle.

Answer: (d) spermatogonia – spermatocyte – spermatid – sperms

Explanation:
1. Spermatogenesis proceeds from spermatogonia to spermatocytes to spermatids and finally spermatozoa (sperms).

Teacher's Note:
1. Spermatogonia are diploid cells at the start.
2. Remember the order: gonia, cyte, tid, zoa.

Answer: (c) seminiferous tubules and provide, nutrition to germ cells

Explanation:
1. Sertoli cells are found in the seminiferous tubules and provide nutrition to the germ cells.

Teacher's Note:
1. They are also called nurse cells.
2. Sertoli cells nourish the sperm.

Answer: (a) fructose and calcium

Explanation:
1. Seminal plasma contains fructose (an energy source for sperms), calcium and certain enzymes.

Teacher's Note:
1. It is secreted by the seminal vesicles, prostate and bulbourethral glands.
2. Fructose supplies sperms with energy.