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
Robin Hill discovered that the isolated chloroplasts from plants can release oxygen when they are illuminated by sunlight in the presence of a suitable electron acceptor. This showed:
I. oxygen () is produced by a reaction that is separate from carbon dioxide () fixation.
II. the reaction in which oxygen is released requires light.
III. the light dependent reaction of photosynthesis is a result of a series of redox reactions.
1. I and II only
2. I and III only
3. II and III only
4. I, II and III
The reactions of the Calvin cycle can take place as long as which of the following products of the light dependent reactions are available?
1. | Water and Glucose | 2. | Water and ATP |
3. | Oxygen and Carbon dioxide | 4. | ATP and NADPH |