Multiple Choice Questions

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Assertion: On touching radial artery in our wrist, we feel pulse waves.

Reason : The heart beats originate from the sinoatrial node (SA node) on the right atrium.

  • If both assertion and reason are true and reason is the correct explanation of assertion.

  • If both assertion and reason are hue but reason is not the correct explanation of assertion.

  • If assertion is true but reason is false.

  • If both assertion and reason are false.


B.

If both assertion and reason are hue but reason is not the correct explanation of assertion.

Pulse is the rhythmic contraction and relaxation in the aorta and its main arteries. The pulse rate is  same as the heart rate because an artery pulses every time the heart beats. It is usually taken on the radial artery in the wrist but it can be taken on any artery that flows near enough to the surface of the body to be felt. The heart beat originates from the sinoatrial node (SA node)- a pacemaker. It is a mass of neuromuscular tissue.

Atrioventricular node(AV node) is situated in the wall of right atrium. It picks up the wave of concentration propogated by SA node. Bundle of His originates from AV node. They further divide into a network of fine fibres known as Purkinje fibres.


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Which of the following organelles contain DNA?

(i) Mitochondria (ii) Chloroplasts (iii) Golgi bodies (iv) Ribosomes

  • (i) and (ii)

  • (ii) and (iii)

  • (i) only

  • (iv) only


Assertion : Small intestine is the principal organ for absorption of nutrients.

Reason : Absorption of water, simple sugars and alcohol etc. takes place in small intestine.

  • If both assertion and reason are true and reason is the correct explanation of assertion.

  • If both assertion and reason are hue but reason is not the correct explanation of assertion.

  • If assertion is true but reason is false.

  • If both assertion and reason are false.


Select the option having all the correct characteristics.

  • Structure Percentage of WBCs Function
    0.3 - 0.5 Phagocytic
  • Structure Percentage of WBCs Function
    0.5 - 1.0 Secrete histamine and serotonin
  • Structure Percentage of WBCs Function
    30 - 40 Defense against parasites
  • Structure Percentage of WBCs Function
    30 - 40 Allergic reactions

Which of the following plant growth regulators (PGRs) promotes root initiation, flowering and induced parthenocarpy?

  • Gibberellin

  • Auxin

  • Cytokinin

  • Ethylene


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Select the correct pair amongst the following

  • Spring wood- light colour, high density

  • Spring wood - dark colour, low density

  • Autumn wood - light colour, high density

  • Autumn wood - dark colour, high density


Carbon dioxide (CO2) diffuses into blood from tissue site and passes to alveolar site in the form of

  • bicarbonate; 70%

  • bicarbonate; 20 - 25%

  • carbaminohaemoglobin; 60 - 70%

  • carbaminohaemoglobin; 7%


Assertion : On plotting the length of the root against time, a linear curve is obtained.

Reason : An elongating rout exemplifies arithmetic growth.

  • If both assertion and reason are true and reason is the correct explanation of assertion.

  • If both assertion and reason are hue but reason is not the correct explanation of assertion.

  • If assertion is true but reason is false.

  • If both assertion and reason are false.


Assertion : Protostele is the simplest stele.

Reason : Protostele is the most advanced type of stele.

  • If both assertion and reason are true and reason is the correct explanation of assertion.

  • If both assertion and reason are true but reason is not the correct explanation of assertion.

  • If assertion is true but reason is false.

  • If both assertion and reason are false.


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Assertion : A mutual exchange of sperms occurs between two earthworms during mating.

Reason : Mature sperms and egg cells and nutritive fluid are deposited in cocoons produced by gland cells of clitellum.

  • If both assertion and reason are true and reason is the correct explanation of assertion.

  • If both assertion and reason are true but reason is not the correct explanation of assertion.

  • If assertion is true but reason is false.

  • If both assertion and reason are false.