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Medical
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16 pollen grains, beacause each pollen mother cell produces 4 pollen grains.
Medical
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Fruit and leaf drop at early stages can be prevented by the application of

  • Option 1)

    Cytokinins

  • Option 2)

    Ethylene

  • Option 3)

    Auxins

  • Option 4)

    Gibberellic acid

 
As learnt Auxin - Tryptophan is the precursor of Indole acetic acid (IAA, natural auxin). Important biassay of auxins are Avena curvature test and cross root inhibition test.   - wherein Discovered by Went. NAA and 2,4-D are auxins which prevent fruit drop in tomato and citrus respectively.   Option 1) Cytokinins This option is incorrect Option 2) Ethylene This option is incorrect Option...
Medical
117 Views   |  

The water potential of pure water is:

  • Option 1)

    Zero

  • Option 2)

    Less than zero

  • Option 3)

    More than zero but less than one

  • Option 4)

    More than one

 

As discussed in

Water Potential (Ψw) -

Difference between the free energy of water molecules in pure water and the energy of water in any other system.

- wherein

At atmospheric pressure Ψw is zero for pure water.

 

 Water potential of pure water is zero


Option 1)

Zero

This solution is correct.

Option 2)

Less than zero

This solution is incorrect.

Option 3)

More than zero but less than one

This solution is incorrect.

Option 4)

More than one

This solution is incorrect.

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Medical
309 Views   |  

With reference to factors affecting the rate of photosynthesis, which of the following statements is not correct?

  • Option 1)

    Light saturation for CO2 fixation occurs at 10% of full sunlight

  • Option 2)

    Increasing atmospheric CO2 concentration upto 0.05% can enhance CO2 fixation rate

  • Option 3)

    C3 plants responds to higher temperatures with enhanced photosynthesis while C4 plants have much lower temperature optimum

  • Option 4)

    Tomato is a greenhouse crop which can be grown in CO2 - enriched atmosphere for higher yield

 

1

Medical
526 Views   |  

Which statement is wrong for Krebs' cycle?

  • Option 1)

    There are three points in the cycle where NAD+ is reduced to NADH+H+

  • Option 2)

    There is one point in the cycle where FAD+ is reduced to FADH2

  • Option 3)

    During conversion of succinyl CoA to succinic acid, a molecule of GTP is synthesised

  • Option 4)

    The cycle starts with condensation of acetyl group (acetyl CoA) with pyruvic acid to yield citric acid

 
As discussed in Kreb's cycle TCA / Citric Acid Cycle - It operates in the mitochondria matrix. All enzymes of Kreb's cycle is present in matrix but succinate dehydrogenase is present on inner mitochondrial membrane. 2 Acetyl CoA + 6H2O + 6NAD+ + 2FAD + 2GDP + 2Pi  4Co2 + 2H2O + 6NADH + 6H+ + 2FADH2 + 2GTP + 2 Coenzyme A - wherein    Kreb's cycle starts with the synthesis of citrate by addition...
Medical
335 Views   |  

Which of the following facilitates opening of stomatal aperture?

  • Option 1)

    Contraction of outer wall of guard cells

  • Option 2)

    Decrease in turgidity of guard cells

  • Option 3)

    Radial orientation of cellulose microfibrils in the cell wall of guard cells

  • Option 4)

    Longitudinal orientation of cellulose microfibrils in the cell wall of guard cells

 
As discussed in Opening and closing of stomata - This is governed by the change in osmotic pressure or turgidity of guard cells. - wherein When guard cells are turgid, stomata open and when guard cells are flaccid, stomata close.     Increase in the turgidity of guard cells, which is due to radial orientation of cellulose microfibrils in the cell wall. Option 1) Contraction of outer wall of...
Medical
358 Views   |  

Phosphonol pyruvate (PEP) is the primary CO2 acceptor in :

  • Option 1)

    C3 plants

  • Option 2)

    C4 plants

  • Option 3)

    C2 plants

  • Option 4)

    C3 and C4 plants

 
As learnt Hatch Slack pathway - Regular mode of CO2 fixation in number of tropical plants. First product is 4-carbon compound, hence, known as C4.  - wherein    In C4 plant CO2 is accepted by PEP forming oxaloacetic acid. Option 1) C3 plants This option is incorrect Option 2) C4 plants This option is correct Option 3) C2 plants This option is incorrect Option 4) C3 and C4 plants This option...
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