Multiple Choice Questions

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The total number of nitrogenous bases in human genome is estimated to be about

  • 3.5 million

  • 35 thousand

  • 35 million

  • 3.1 billion.


D.

3.1 billion.

Genome size is usually stated as the total number of base pairs; the human genome contains roughly 3 billion base pairs.


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A person is wearing spectacles with concave lenses for correcting vision. While not using the glasses, the image of a distant object in his case will be formed

  • on the blind spot

  • behind the retina

  • in front of the retina

  • on the yellow spot


Examine the diagram of the two cell types A and B given below and select the correct option

     A                B

  • Cell A is the rod cell found evenly all over retina

  • Cell A is the cone cell more concentrated in the fovea central is

  • Cell B is concerned with colour vision in bright light

  • Cell A is sensitive to low light intensities


Unidirectional transmission of a nerve impulse through nerve fibre is due to the fact that

  • nerve fibre is insulated by a medullary sheath

  • sodium pump starts operating only at the cyton and then continues into the nerve fibre

  • neurotransmitters are released by dendrites and not by axon endings

  • neurotransmitters are released by the axon endings and not by dendrites.


The part of an eye which acts like a diaphragm of a photographic camera is

  • pupil

  • iris

  • lens

  • cornea


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The dendrite carries impulses

  • towards the cyton

  • away from cyton

  • across the body

  • from one neuron to another


A person who shows unpredictable moods, outbursts of emotion, quarrelsome behaviour and conflicts with others is suffering from

  • borderline personality disorder (BPD)

  • mood disorder

  • addictive disorder 

  • schizophrenia.


Given below is a table comparing the effects of sympathetic and parasympathetic nervous system
for four feature (a-d). Which one feature is correctly described

  • Feature Sympathetic nervous system Parasympathetic nervous system
    a) Salivary glands  Stimulate Secretion Inhibit Secretion
  • b) Pupil of the eye Dilate Constricts
  • c) Heart rate  Decreases  Increases
  • d) Intestinal peristalsis Stimulates  Inhibits

Cochlea of mammalian internal ear is concerned with

  • hearing

  • balance of body posture

  • both (a) and (b)

  • perception changes of atmospheric pressure


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Cerebrospinal fluid is present

  • beneath the pia mater

  • between piamater and arachnoid

  • between arachnoid and duramater

  • between duramater and cranium


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