Assertion(A) : The atmospheric concentration of CO2 at which photosynthesis just compensates for respiration is referred to as CO2 compensation point.
Reason(R) : The CO2 compensation point in reached when the amount of CO2 uptake is less than that generated through respiration because the level of CO2 in the atmosphere is more than that required for achieving CO2 compensation point.
1. Both assertion and reason are true and the reason is the correct explanation of assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but the reason is false.
4. If both assertion and reason are false statements.
2. Both assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but the reason is false.
4. If both assertion and reason are false statements.
Subtopic: Â Photorespiration |
Level 3: 35%-60%
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Assertion(A) : Dark reaction is purely enzymatic reaction.
Reason(R) : It occurs only in absence of light.
Reason(R) : It occurs only in absence of light.
1. Both assertion and reason are true and the reason is the correct explanation of assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but the reason is false.
4. If both assertion and reason are false statements.
Subtopic: Â Dark Reaction: Biosynthetic Phase |
 76%
Level 2: 60%+
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| Assertion(A): | Protons produced by photolysis of water accumulate in the lumen of thylakoids. |
| Reason(R): | Photolysis of water takes place towards lumen side of thylakoid. |
| 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 statements. |
Subtopic: Â Chemiosmotic hypothesis |
 80%
Level 1: 80%+
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| Assertion(A) : | C3 plants can show CO2 fertilisation effect. |
| Reason(R) : | If atmospheric CO2 concentration increases then, C3 plants will be benefitted. |
| 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 statements. |
Subtopic: Â C4 Cycle (Hatch & Slack Pathway) |
 72%
Level 2: 60%+
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| Assertion(A) : | Tomatoes and bell pepper are C4 plants. |
| Reason(R) : | The current atmospheric CO2 concentration is nonlimiting for these plants. |
| 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 the (R) is false. |
| 4. | Both (A) and (R) are false statements. |
Subtopic: Â C4 Cycle (Hatch & Slack Pathway) |Â C4 Plants Examples |
 60%
Level 2: 60%+
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| Assertion(A) : | The C4 plants respond to higher temperatures and show higher rate of photosynthesis than C3 plants. |
| Reason(R) : | C4 plants are adapted to live in dry warm tropical areas and lack photorespiration. |
| 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 the (R) is false. |
| 4. | Both (A) and (R) are false statements. |
Subtopic: Â C4 Cycle (Hatch & Slack Pathway) |Â C4 Plants Examples |
 79%
Level 2: 60%+
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| Assertion(A) : | The light saturation occurs at 10% of the full sunlight in most of the plants. |
| Reason(R) : | Light is rarely a limiting factor for most of the plants except those which grows in a shade or dense forests. |
| 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 the (R) is false. |
| 4. | Both (A) and (R) are false statements. |
Subtopic: Â Factors Affecting Photosynthesis |
 54%
Level 3: 35%-60%
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| Assertion(A) : | The tropical plants have a higher temperature optimum than the temperate plants. |
| Reason(R) : | All the tropical plants lack photorespiration |
| 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 the (R) is false. |
| 4. | Both (A) and (R) are false statements. |
Subtopic: Â Factors Affecting Photosynthesis |
 57%
Level 3: 35%-60%
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Assertion(A) : Water stress causes the stomata to close thus, reducing the CO2 availability to plants.
Reason(R) : Water stress makes leaves wilt, thus, reducing the surface area of the leaves and their metabolic activity as well.
Reason(R) : Water stress makes leaves wilt, thus, reducing the surface area of the leaves and their metabolic activity as well.
1. Both assertion and reason are true and the reason is the correct explanation of assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but the reason is false.
4. If both assertion and reason are false statements.
Subtopic: Â Factors Affecting Photosynthesis |
 58%
Level 3: 35%-60%
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Which of the following constitutes Hill reaction?
| 1. | Photolysis by chloroplasts |
| 2. | Photolysis of water by isolated chloroplasts forming ATP and NADPH H+ |
| 3. | Photolysis of water by isolated illuminated chloroplasts causing reduction of some chemicals and liberation of oxygen |
| 4. | Photolysis of water liberating oxygen and hydrogen by illuminated isolated chloroplasts |
Subtopic: Â Historical View: Experiments |
Level 3: 35%-60%
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