1. | Five G3P molecules produce three RuBP molecules, using up three molecules of ATP. |
2. | Three G3P molecules produce five RuBP molecules, using up three molecules of ATP. |
3. | Three G3P molecules produce five RuBP molecules, using up five molecules of ATP. |
4. | Five G3P molecules produce three RuBP molecules, using up five molecules of ATP. |
Statement I: | CO2 is initially incorporated into a four-carbon organic acid (either malate or aspartate) in the mesophyll cells. |
Statement II: | The chloroplasts of the bundle sheath cells convert this CO2 into carbohydrates by the conventional C3 pathway. |
I: | is the most abundant enzyme in the world |
II: | is characterised by the fact that its active site can bind to both CO2 and O2 |
III: | has a much greater affinity for CO2 when the CO2: O2 is nearly equal |
Assertion (A): | Except for plants in shade or in dense forests, light is rarely a limiting factor for photosynthesis in nature. |
Reason (R): | Increase in incident light beyond a point causes the breakdown of chlorophyll and a decrease in photosynthesis. |
1. | (A) is True but (R) is False |
2. | Both (A) and (R) are True and (R) explains (A) |
3. | Both (A) and (R) are True but (R) does not explain (A) |
4. | (A) is False but (R) is True |
Assertion (A): | Current availability of CO2 levels is limiting to the C3 plants. |
Reason (R): | Carbon dioxide is the major limiting factor for photosynthesis. |
1. | (A) is True but (R) is False |
2. | Both (A) and (R) are True and (R) explains (A) |
3. | Both (A) and (R) are True but (R) does not explain (A) |
4. | (A) is False but (R) is True |
I: | Water stress causes the stomata to close, hence reducing the CO2 availability. |
II: | Water stress also makes leaves wilt, thus, increasing the surface area of the leaves and their metabolic activity as well. |
Assertion (A): | Plants that do not use PEP-carboxylase in carbon fixation are called C3 plants. |
Reason (R): | The primary carboxylation reaction in C3 plants, catalyzed by RuBisCO, produces the three-carbon 3-phosphoglyceric acids directly in the Calvin-Benson cycle. |
1. | (A) is True but (R) is False |
2. | Both (A) and (R) are True and (R) explains (A) |
3. | Both (A) and (R) are True but (R) does not explain (A) |
4. | (A) is False but (R) is True |