Q. No.In PS-II, the reaction centre chlorophyll a molecule is called ______.
| 1. | P680 | 2. | P700 |
| 3. | P890 | 4. | Q cycle |
Subtopic: Â Light Reactions |
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Which of the following is a characteristic feature of Photosystem I (PS I) in the light reactions of photosynthesis?
| 1. | It has a reaction centre chlorophyll a molecule called P680. |
| 2. | Its reaction centre, chlorophyll a molecule, has an absorption peak at 700 nm. |
| 3. | It is responsible for the splitting of water molecules. |
| 4. | It is the first photosystem to function in the sequence of light reactions. |
Subtopic: Â Light Reactions |
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What are the main components of a photosystem in photosynthesis?
| 1. | Chlorophyll molecules, reaction centre, and light-harvesting complex |
| 2. | ATP synthase, electron carriers, and NADPH |
| 3. | Carbohydrate molecules, thylakoid lumen, and oxygen |
| 4. | Stroma enzymes, plastids, and ribosomes |
Subtopic: Â Introduction |Â Photosynthetic Pigments |Â Pigments |Â Light Reactions |
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The reaction centers chlorophyll a of PSI and PSII have an absorption peak respectively at:
| 1. | 680 nm and 700 nm | 2. | 630 nm and 730 nm |
| 3. | 730 nm and 630 nm | 4. | 700 nm and 680 nm |
Subtopic: Â Light Reactions |
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Consider the given two statements:
| Statement I: | Photosystem II absorbs light at a wavelength of 700 nm. |
| Statement II: | Photosystem I absorbs light at a wavelength of 680 nm. |
| 1. | Statement I is correct; Statement II is correct |
| 2. | Statement I is correct; Statement II is incorrect |
| 3. | Statement I is incorrect; Statement II is correct |
| 4. | Statement I is incorrect; Statement II is incorrect |
Subtopic: Â Light Reactions |
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During the light reactions of photosynthesis, absorption of photons leads to movement of electrons through a series of carriers embedded in the thylakoid membrane.
This movement ultimately results in:
This movement ultimately results in:
| 1. | Fixation of carbon dioxide into sugars |
| 2. | Generation of proton gradient for ATP synthesis |
| 3. | Direct synthesis of glucose molecules |
| 4. | Release of oxygen without ATP formation |
Subtopic: Â Light Reactions |
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During oxygenic photosynthesis in chloroplasts, the liberated oxygen comes from ______ and the reactions leading to its liberation are associated with ______.
1. CO2, PS II
2. H2O, PSII
3. CO2, Calvin cycle
4. H2O, PS I
Subtopic: Â Light Reaction: Electron Transport |Â Light Reactions |
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Light is composed of particles of energy called
1. carotenoids
2. reaction centers
3. photons
4. antenna complexes
1. carotenoids
2. reaction centers
3. photons
4. antenna complexes
Subtopic: Â Light Reactions |
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In ____________, there is a one-way flow of electrons to \(\mathrm{NADP}^{+}\), forming NADPH.
1. crassulacean acid metabolism
2. the Calvin cycle
3. photorespiration
4. noncyclic electron transport
1. crassulacean acid metabolism
2. the Calvin cycle
3. photorespiration
4. noncyclic electron transport
Subtopic: Â Light Reactions |
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How does Photosystem II (PS II) ensure a continuous supply of electrons during the light-dependent reactions?
| 1. | By directly accepting electrons from NADPH produced in the Calvin cycle. |
| 2. | Through the breakdown of carbon dioxide molecules in the thylakoid lumen. |
| 3. | Through the photolysis of water, which releases electrons, protons, and oxygen. |
| 4. | By transferring electrons back from Photosystem I (PS I) via cyclic electron flow. |
Subtopic: Â Light Reactions |
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