The correct statements about photosynthesis include:
I: | the light-dependent reactions can occur only in the light, the light-independent reactions only in the dark |
II: | photorespiration is more efficient at producing glucose than is photosynthesis |
III: | the light-dependent reactions produce the energy-rich compounds that are used to run the light-independent reactions |
1. | I only | 2. | III only |
3. | I and III only | 4. | II and III only |
Study the given diagram where ‘X’ represents the absorption spectrum of chlorophyll a and ‘Y’ represents the action spectrum of photosynthesis. The conclusions that can be drawn include:
I: | Chlorophyll a is the main pigment in photosynthesis. |
II: | Violet-Blue and Red wavelengths are very effective for photosynthesis. |
III: | Chlorophyll a is the only pigment capable of absorbing light. |
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II and III |
Identify the incorrect statement regarding the light independent reactions in photosynthesis:
1. These reactions occur in the stroma.
2. They use the products (ATP and NADPH) of light-dependent reactions.
3. They occur in the absence of light and hence are called the dark reactions.
4. The three phases are carbon fixation, reduction reactions, and ribulose 1,5-bisphosphate (RuBP) regeneration.
The number of turns of Calvin cycle required to produce one molecule of Glyceraldehyde 3 Phosphate is:
1. | 1 | 2. | 2 |
3. | 3 | 4. | 6 |
The number of molecules of NADPH and ATP required respectively to reduce six molecules of carbon dioxide to glucose in Calvin cycle?
1. 6 and 6 | 2. 12 and 12 |
3. 12 and 18 | 4. 18 and 12 |
Identify the correct statement regarding the functioning of photosystem II?
1. | The reaction center is P700. |
2. | It works after PS I in non cyclic photophosphorylation. |
3. | Water splits and carbon dioxide is released. |
4. | The electron vacancies in P680 are filled by electrons derived from water. |
Consider the following two statements regarding RuBisCO:
I: | When carbon dioxide is the substrate, the product of the carboxylase reaction is finally two molecules of glycerate-3-phosphate. |
II: | When molecular oxygen is the substrate, the products of the oxygenase reaction are two molecules of phosphoglycolate. |
1. | Only I is correct | 2. | Only II is correct |
3. | Both I and II are correct | 4. | Both I and II are incorrect |
Identify the correct statements regarding RuBisCO:
I: | It catalyzes the carboxylation of \(CO_2\) to ribulose 1,5-bisphosphate. |
II: | It initiates photorespiration when the \(CO_2/O_2\) ratio is low. |
III: | It catalyzes the reduction of two molecules of PGAL to form glucose. |
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II and III |
The products of non-cyclic photophosphorylation include:
1. | ATP and P700 | 2. | ATP and NADPH |
3. | ADP and NADP | 4. | P700 and P680 |
The and photosynthesis pathways are so called because the initial carbon fixation product in them are respectively:
1. | pyruvate; malate |
2. | malate; pyruvate |
3. | 3-phosphoglycerate; oxaloacetic acid |
4. | glyceraldehyde 3-phosphate; phospho-enol-pyruvate (PEP) |