Calcium is important in skeletal muscle contraction because it f

Subject

Biology

Class

NEET Class 12

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 Multiple Choice QuestionsMultiple Choice Questions

1.

Match the items given in Column I with those in Column II and select the correct option given below:
column i column ii
a Tricuspid valve i Between left atrium and left ventricle
b Bicuspid valve ii Between right ventricle and pulmonary artery
c Semilunar valve iii Between right atrium and right ventricle

  • a b c
    iii i ii
  • a b c
    i iii ii
  • a b c
    ii i iii
  • a b c
    i ii iii

2.

Match the items given in Column I with those in Column II and select the correct option given below:
Column i Column ii
a Tidal volume i 2500 – 3000 mL
b Inspiratory Reserve volume ii 1100 – 1200 mL
c Expiratory Reserve volume iii 500 – 550 mL
d Residual volume iv 1000 – 1100 mL

  • a b c d
    iii ii i iv
  • a b c d
    iii i iv ii
  • a b c d
    iv iii ii i
  • a b c d
    i iv ii iii

3.

Which of the following is an amino acid derived hormone?

  • Epinephrine

  • Ecdysone

  • Estriol

  • Estradiol


4.

Which of the following structures or regions is incorrectly paired with its functions?

  • Medulla oblongata : Controls respiration and cardiovascular reflexes

  • Limbic system: consists of fibre tracts that interconnect different regions of brain; controls movement.

  • Corpus callosum: band of fibres connecting system: left and right cerebral hemispheres.

  • Hypothalamus: production of releasing hormones and regulation of temperature,the hunger and thirst.


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5.

The transparent lens in the human eye is held in its place by

  • ligaments attached to the ciliary body

  • ligaments attached to the iris

  • smooth muscles attached to the ciliary body

  • smooth muscles attached to the iris


6.

Which of the following hormones can play a significant role in osteoporosis?

  • Aldosterone and Prolactin

  • Progesterone and Aldosterone

  • Parathyroid hormone and Prolactin

  • Estrogen and Parathyroid hormone


7.

Which of the following gastric cells indirectly help in erythropoiesis?

  • Chief cells

  • Mucous cells

  • Parietal cells

  • Goblet cells


8.

Match the items given in Column I with those in Column II and select the correct option given below:
Column I Column II
a Fibrinogen i Osmotic balance
b Globulin ii Blood clotting
c Albumin iii Defence
mechanism

  • a b c
    iii ii i
  • a b c
    i ii iii
  • a b c
    ii iii i
  • a b c
    i ii iii

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9.

Which of the following is an occupational respiratory disorder?

  • Anthracis

  • Silicosis

  • Emphysema

  • Botulism


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10.

Calcium is important in skeletal muscle contraction because it

  • Binds to troponin to remove the masking of active sites on actin for myosin.

  • Activates the myosin ATPase by binding to it.

  • Prevents the formation of bonds between the myosin cross bridges and the actin filament.

  • Detaches the myosin head from the actin filament.


A.

Binds to troponin to remove the masking of active sites on actin for myosin.

The signal for contraction increase Ca++ level many folds in the sarcoplasm.

Ca++ now binds with sub-unit of troponin (troponin 'C') which is masking the active site on actin filament and displaces the sub-unit of troponin.

Once the active site is exposed, head of the myosin attaches and initiate contraction by sliding the actin over myosin.


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