Photorespiration is a wasteful process. Why is it so?
1. | The number of ATP molecules produced in the pathway is very low. |
2. | The number of NADPH molecules produced in the pathway is very low. |
3. | The synthesis of sugars in the pathway requires a large input of ATP energy. |
4. | There is neither synthesis of sugars, nor of ATP in the pathway. |
Identify the correctly matched rows:
C3 | C4 | ||
I: | Productivity | Low | High |
II: | CO2 compensation point | Low | Low |
III: | Temperature optimum | 20 – 250 C | 30 – 450 C |
1. | Only I and II | 2. | Only I and III |
3. | Only II and III | 4. | I, II and III |
Except for plants in shade or in dense forests, light is rarely a limiting factor in nature. This is because:
1. | Dark reactions do not depend on light |
2. | The rate of photosynthesis can be increased by higher carbon dioxide and lower temperatures even in low light conditions |
3. | Light saturation occurs at 10 % of full sunlight |
4. | Carbon fixation is independent of enzymes |
Which pigment acts directly to convert light energy to chemical energy ?
1. | Chlorophyll a | 2. | Chlorophyll b |
3. | Xanthophylls | 4. | Carotenoid |
Which light range is most effective in photosynthesis?
1. Blue | 2. Green |
3. Red | 4. Violet |
The correct sequence of flow of electrons in the light reaction is
1. | PSII, plastoquinone, cytochromes, PS I, ferredoxin |
2. | PSI, plastoquinone, cytochromes, PS II, ferredoxin |
3. | PSI, ferredoxin, PS II, |
4. | PSI, plastoquinone, cytochromes, PS II, ferredoxin |
The enzyme that is not found in a plant is
1. RuBP Carboxylase
2. PEP Carboxylase
3. NADP reductase
4. ATP synthase
Chloroplasts:
I. have their own DNA and make all proteins needed by them
II. have a uniparental inheritance
III. cannot be made by the plant cell
1. Only I and II are correct
2. Only I and III are correct
3. Only II and III are correct
4. I, II and III are correct
Carbon dioxide tagged with heavy isotope of oxygen was fed to a green algae in the presence of sunlight. Which of the following compounds would not be tagged with this isotope?
1. Phosphoglycerate
2. Phosphoglyceraldehyde
3. Glucose
4. Oxygen
Light reaction of photosynthesis does not include:
1. chemiosmosis
2. oxygen liberation
3. charge separation
4. electron transport