The 2-carbon compound formed in photorespiration is:
1. | Acetyl CoA | 2. | Phosphoglycolate |
3. | Acetic acid | 4. | Ethanol |
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