Human Reproduction

NEET Biology · 134 questions · Page 5 of 14 · Click an option or "Show Solution" to reveal answer

Q41

Fertilizins are emitted by

A immature eggs

B mature eggs

C sperms

D polar bodies

Correct Answer

Option B

Solution

(b) A glycoprotein fertilizin is secreted by a mature egg. Sperm secretes antifertilizin.

Q42

The correct sequence of spermatogenetic stages leading to sperm formation is:

A spermatogonia-spermatocyte-spermatids-sperm

B spermatid-spermatocyte-spermatogonia-sperms

C spermatogonia-spermatocyte-spermatid-sperm

D spermatocyte-spermatogonia-spermatid-sperm

Correct Answer

Option A

Solution

(a) Spermatogonia → spermatocytes → spermatids → spermatozoa.

Q43

In telolecithal egg the yolk is found

A all over the egg

B on one side

C both the sides

D centre

Correct Answer

Option B

Solution

(b) On the basis of distribution of yolk the eggs are of following types: (i) Homolecithal : Evenly distributed yolk. (ii) Telolecithal : Most of the yolk near the vegetal pole, cytoplasm and nucleus lie near animal pole. (iii) Centrolecithal : Centrally placed yolk surrounded by cytoplasm.

Q44

Which one of the following statements is false in respect of viability of mammalian sperm?

A Sperm is viable for only up to 24 hours.

B Survival of sperm depends on the pH of the medium and is more active in alkaline medium.

C Viability of sperm is determined by its motility.

D Sperms must be concentrated in a thick suspension.

Correct Answer

Option A

Solution

(a) Sperm is viable for 2-3 days, not just 24 hours.

Q45

The foetal ejection reflex in humans triggers release of

A Oxytocin from maternal pituitary

B Oxytocin from foetal pituitary

C Human Chorionic Gonadotropin (hCG) from placenta

D Human Placental Lactogen (hPL) from placenta

Correct Answer

Option A

Solution

(a) Parturition is induced by a complex neuroendocrine mechanism.

The signals for parturition originate from the fully developed foetus and the placenta which induce mild uterine contractions called foetal ejection reflex.

This triggers release of oxytocin from the maternal pituitary.

Q46

The Leydig cells found in the human body are the secretory source of

A Progesterone

B intestinal mucus

C glucagon

D androgens

Correct Answer

Option D

Solution

(d) Leydig cells found in testis is the endocrine portion of the testis which are present in between seminiferous tubules secretes androgens or male sex hormone e.g. testosterone.

Sperm capacitation refers to the physiological changes spermatozoa must undergo in order to have the ability to penetrate and fertilize an egg.

Q47

The foetal ejection reflex in humans triggers release of

A Oxytocin from maternal pituitary

B Oxytocin from foetal pituitary

C Human Chorionic Gonadotropin (hCG) from placenta

D Human Placental Lactogen (hPL) from placenta

Correct Answer

Option A

Solution

(a) Foetal ejection reflex triggers release of oxytocin from the maternal pituitary.

Q48

Which one of the following is not the function of placenta?

A secretes estrogen

B facilitates removal of carbon dioxide and waste material from embryo.

C secretes oxytocin during parturition

D facilitates supply of oxygen and nutrients to embryo

Correct Answer

Option C

Solution

Q49

The first movements of the foetus and appearance of hair on its head are usually observed during which month of pregnancy?

A Fourth month

B Fifth month

C Sixth month

D Third month

Correct Answer

Option B

Solution

(b) First movements of the foetus and hair on head appear by the end of fifth month of pregnancy.

Q50

If for some reason, the vasa efferentia in the human reproductive system gets blocked, the gametes will not be transported from

A testes to epididymis

B epididymis to vas deferens

C ovary to uterus

D vagina to uterus

Correct Answer

Option A

Solution

(a) If the vasa efferentia in the human reproductive system get blocked the gametes will not be transformed from testes to epididymis.

The seminal vesicles produce a viscous, fructose-rich fluid forming around $65-70$ percentage of the semen base.

The white color of the semen is due to secretion from the prostate glands containing enzymes, citric acid, lipids, and acid phosphatase.

This forms around $25-30$ percentage of the semen base.

At each ejaculation around 200-500 million sperms are released by the testes.

This forms about $2-5$ percentage of the semen composition.

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