In Kranz anatomy, the bundle sheath cells have
1. | thick walls, many intercellular spaces and few chloroplasts |
2. | thin walls, many intercellular spaces and no chloroplasts |
3. | thick walls, no intercellular spaces and large number of chloroplasts |
4. | thin walls, no intercellular spaces and several chloroplasts |
With reference to factors affecting the rate of photosynthesis, which of the following statements is not correct?
1. | Increasing atmospheric concentration up to 0.05 % can enhance fixation rate |
2. | plants respond to higher temperatures with enhanced photosynthesis while plants have much lower temperature optimum |
3. | Tomato is a greenhouse crop which can be grown in – enriched atmosphere for higher yield |
4. | Light saturation for fixation occurs at 10% of full sunlight |
Assertion(A): | Not all organisms use carbon dioxide as a source of carbon atoms to carry out photosynthesis. |
Reason(R): | Photoheterotrophs use organic compounds, rather than carbon dioxide, as a source of carbon. |
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. |
Assertion(A): | The Calvin cycle in most plants occurs during daylight. |
Reason(R): | None of the steps of the Calvin cycle require light directly |
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 |
Given below are two statements:
Assertion (A): | Action spectrum of photosynthesis is much broader than the absorption spectrum of chlorophyll a. |
Reason (R): | Accessory pigments with different absorption spectra are also present in chloroplasts. |
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. |
Assertion: | Photophosphorylation in chloroplasts and oxidative phosphorylation in mitochondria are different. |
Reason: | In chloroplasts the high energy electrons come from food while in mitochondria they come from water. |
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 |
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R):
Assertion (A): | The reaction center of PS I is known as P700 and the reaction center of PS II is known as P680. |
Reason (R): | PS I functions first in the light reactions. |
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. |
Assertion: | Transfer of electrons from the split water molecule to P680+ is easy. |
Reason: | P680+ is the strongest biological oxidizing agent known. |
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. |
Assertion(A): | The electrons of NADPH are more readily available for the reactions of Calvin cycle than those of water. |
Reason(R): | Two electrons are required for the reduction of NADP+ to NADPH. |
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 |
Assertion: | Mutant plants that are not able to carry out cyclic electron flow do not grow well in intense light conditions. |
Reason: | Cyclic electron flow may be photoprotective. |
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. |