Multiple Choice Questions

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The extra structure that provides nutrition to the embryo is

  • umbilicus

  • amnion

  • chorian

  • placenta


D.

placenta

Placenta is a connection between foetus and mother formed from fusion of allantois, chorian and uterine endometrium.

Functions:

(a) Provides nourishment

(b) Helps in respiration

(c) Helps in excretion

Amnion and chorian are foetal membranes. Amnion helps in protection and chorian helps in nourishment.


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Prothallus of the fern produces

  • Spores

  • Gametes

  • Both (a) and (b)

  • Cones


How many sperm cells are present in an average (3 mL) ejaculation?

  • 200 million

  • 300 million

  • 400 million

  • 500 million


The middle piece of the sperm contains

  • Proteins

  • Centriole

  • Nucleus

  • Mitochondria


In human, during fertilization, a sperm firstly comes in contact with which layer of the ovum

  • Zona pellucida

  • Vitelline membrane

  • Jelly coat

  • Zona radiata


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LH and FSH are collectively called

  • oxytocin

  • samatotrophins

  • luteotropic

  • gonadotropins


Which extraembryonic membrane in humans prevents desiccation of the embryo inside the uterus?

  • Chorion

  • Allantois

  • Yolk sac

  • Amnion


In case of pregnancy, the heartbeat of embryo starts at

  • 4th week

  • 7th week

  •  6th week

  •  5th week


The number of chromosomes in a primary spermatocyte is

  • Same as in spermatid

  • Same as in spermatogonium

  • Help of that in spermatogonium

  • Same as in secondary spermatocyte


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Due to alcohol abuse, brain-related disease Korsakkoff’s syndrome occurs. Which nutrient is responsible for this syndrome?

  • Vitamin-B12

  • Fat

  • Protein

  • Vitamin-B1


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