Assertion: Photorespiration is considered as an evolutionary relic.
Reason: Unlike normal cellular respiration it uses ATP rather than generating it and unlike photosynthesis it produces no sugar.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  3. If the assertion is true but the reason is false
  4. If both the assertion and reason are false

Subtopic:  Photorespiration |

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Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R): 
 

Assertion (A): PEP carboxylase can fix carbon more efficiently than RuBisCO when
it is hot and dry and stomata are partially closed.
Reason (R): PEP carboxylase has a much high affinity for  CO2 than RuBisCO
and no affinity for O2.


In the light of the above statements choose the correct answer from the options given below:
 

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.
Subtopic:  Dark Reaction : Calvin Cycle |
 70%

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Assertion: The primary function of kranz anatomy is to provide a site in which CO2 can be concentrated around RuBisCO, thereby avoiding photorespiration.
Reason: The mesophyll cells have a suberized cell wall and have a low conductance for CO2.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  3. If the assertion is true but the reason is false
  4. If both the assertion and reason are false
Subtopic:  C4 Cycle (Hatch & Slack Pathway) |
 56%

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Assertion: Cyclic electron flow is the only photosynthetic mode of generating ATP for bundle sheath cells.
Reason: Bundle sheath cells contain PS I but no PS II.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  3. If the assertion is true but the reason is false
  4. If both the assertion and reason are false
Subtopic:  C4 Cycle (Hatch & Slack Pathway) |

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Assertion: CAM is an adaptation for increased efficiency in the use of water, and so is typically found in plants growing in arid conditions.
Reason: The most important benefit of CAM to the plant is the ability to leave most leaf stomata open during the day.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false

  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  3. If the assertion is true but the reason is false
  4. If both the assertion and reason are false
Subtopic:  CAM Pathway |
 65%

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Assertion: When simultaneously exposed to light of both red and far red wavelengths, the rate of photosynthesis is far higher than the sum of the red light and far red light photosynthesis rates.
Reason: Two photosystems, processing different wavelengths, cooperate in photosynthesis.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  3. If the assertion is true but the reason is false
  4. If both the assertion and reason are false
Subtopic:  Photosystems |
 73%

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Assertion: A reduction in photorespiration by genetic engineering or because of increasing atmospheric carbon dioxide (due to fossil fuel burning) may not benefit plants as has been proposed.
Reason: Photorespiration may be necessary for the assimilation of nitrate from soil.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  3. If the assertion is true but the reason is false
  4. If both the assertion and reason are false
Subtopic:  Photorespiration |

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Assertion: Plants photosynthesise during the day, whereas they respire at night.
Reason: Photosynthesis can occur in the presence of sunlight whereas respiration cannot.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  3. If the assertion is true but the reason is false
  4. If both the assertion and reason are false
Subtopic:  Introduction | Light Reaction: Electron Transport |

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What conclusions can be drawn from the Moll’s half leaf experiment [the given diagram shows the schematic representation of the experiment]?

What can be said after observing the results of the experiment?
I. Negative starch test by the leaf portion present inside the bottle indicates CO2 is necessary for this process.
II. Negative test of starch, which is also shown by the portion of the leaf present in between the split of the split cork is due to the lack of CO2 and light, thus indicating that both of them are essential requirements.

1. Only I 2. Only II
3. Both I and II 4. None
Subtopic:  Historical View: Experiments |
 65%

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C. B van Niel proved that:
1. Plants produce glucose when they grow.
2. Blue and red light are effective for photosynthesis.
3. It is only the green parts of the plants that could release oxygen.
4. Hydrogen from a suitable oxidizable compound reduces carbon dioxide to carbohydrates.

Subtopic:  Historical View: Experiments |
 65%
From NCERT

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To unlock all the explanations of 38 chapters you need to be enrolled in MasterClass Course.