Generated by claude-sonnet-4-6 · 2026-06-11 09:47 · grounding rag
Model Answer
(i) The internal energy reserve in plants is starch, and in animals it is glycogen. These are used as sources of energy when needed.
(ii) Desert plants keep their stomata closed during the day to prevent water loss. They take in CO₂ at night and store it in the form of organic compounds (as malic acid). During the day, this stored CO₂ is used for photosynthesis when sunlight is available, even though stomata remain closed.
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Explanation
- (i) This is a direct factual point — starch (plants) and glycogen (animals) are the standard expected terms. One mark.
- (ii) This describes CAM (Crassulacean Acid Metabolism) plants, though the term is not required at this level. Key idea: CO₂ is absorbed at night → stored as organic acid → released during day for photosynthesis. Two marks — mention both the night CO₂ absorption and daytime use clearly.
- Note: The source passages provided do not cover these topics directly; these answers are based on NCERT Class 10 Life Processes (Chapter 6) standard textbook content.