NEET Biology: Plant Physiology Practice Questions
14 free multiple-choice questions on Plant Physiology for NEET Biology, each with the correct answer and a step-by-step explanation. Attempt a question, then reveal the solution to check your reasoning.
Practice thousands more Plant Physiology questions in the app →Q1. In the Calvin cycle, what molecule is fixed by the enzyme RuBisCO to initiate the synthesis of organic molecules?
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Correct answer: C — Carbon Dioxide (CO₂)
Carbon dioxide (CO₂) is the inorganic carbon source that is fixed by the enzyme RuBisCO to start the process of synthesizing glyceraldehyde-3-phosphate (G3P).
Q2. Which of the following represents the end product of the overall photosynthesis process?
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Correct answer: D — Glucose and Oxygen
Photosynthesis converts carbon dioxide and water into glucose (food/energy) and oxygen gas.
Q3. Which of the following molecules acts as the immediate energy carrier produced during the light-dependent reactions of photosynthesis, used to power the synthesis of glucose in the Calvin cycle?
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Correct answer: A — NADPH
NADPH (Nicotinamide adenine dinucleotide phosphate) is an energy-carrying molecule that transports high-energy electrons derived from the splitting of water during the light-dependent reactions to the Calvin cycle, where it provides the reducing power for carbon fixation.
Q4. What is the primary role of water (H₂O) in the process of photosynthesis?
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Correct answer: A — As the electron donor in the light reaction
In the light-dependent reactions, water molecules are split (photolysis) to release electrons, protons, and oxygen, which are essential for the subsequent energy production.
Q5. The Calvin cycle, which occurs in the stroma of the chloroplast, primarily uses which energy molecule to fix atmospheric carbon dioxide?
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Correct answer: D — ATP and NADPH
The Calvin cycle requires the energy stored in ATP and the reducing power provided by NADPH (products of the light reactions) to convert CO₂ into glucose.
Q6. Where does the light-dependent reaction take place in the chloroplast?
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Correct answer: B — Thylakoid membrane
Light-dependent reactions occur on the thylakoid membranes within the chloroplasts, where photosystems are embedded.
Q7. What is the primary gaseous byproduct released during the light-dependent reactions of photosynthesis?
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Correct answer: B — Oxygen
Oxygen is released as a byproduct when water is split during the light-dependent reactions.
Q8. Which of the following substances is the essential raw material used by plants to synthesize glucose during photosynthesis?
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Correct answer: A — Carbon Dioxide
Carbon dioxide (CO₂) and water (H₂O) are the primary raw materials that are converted into glucose during the process of photosynthesis.
Q9. Which of the following pigments is responsible for the primary absorption of red and blue light energy in photosynthesis?
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Correct answer: C — Chlorophyll
Chlorophyll strongly absorbs light in the blue and red regions of the visible spectrum, making it the most effective pigment for photosynthesis.
Q10. The splitting of water molecules during the light-dependent reactions results in the release of which gas?
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Correct answer: D — Oxygen
Photolysis of water (H₂O) during the light reactions releases oxygen (O₂) as a byproduct.
Q11. Where are the thylakoids, the membrane-bound structures necessary for light reactions, located inside the chloroplast?
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Correct answer: A — In the grana stacks
Thylakoids are flattened sacs located within the chloroplast, often stacked into grana, where the light-dependent reactions occur.
Q12. Which pigment is primarily responsible for capturing light energy during the initial stage of photosynthesis?
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Correct answer: D — Chlorophyll
Chlorophyll is the green pigment essential for absorbing light energy to initiate the process of photosynthesis.
Q13. Photosynthesis requires the absorption of light energy. Which cells in the plant tissue are optimally positioned to intercept the maximum amount of incoming sunlight?
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Correct answer: D — Palisade mesophyll cells
Palisade mesophyll cells are positioned directly against the upper surface of the leaf to maximize the capture of incident sunlight, making them highly efficient light absorbers.
Q14. Which intermediate molecule is produced during the light-dependent reactions and used to power the subsequent synthesis reactions?
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Correct answer: B — ATP
The light-dependent reactions ultimately produce energy in the form of ATP and reducing power in the form of NADPH.
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