Two green plants are kept separately in oxygen free containers, one in the dark and other in sunlight. It was observed that plant kept in dark could not survive longer. Give reason for this observation.
Generated by claude-sonnet-4-6 · 2026-06-11 09:50 · grounding rag
Model Answer
The plant kept in dark could not perform photosynthesis as sunlight is essential for it. Without photosynthesis, no carbohydrates (food) were produced. The plant used up all its stored starch for respiration and, with no energy reserve left, it could not survive longer. The plant in sunlight continued photosynthesis and stayed alive.
Source: Life Processes, Section 5.2.1 Autotrophic Nutrition
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Explanation
- The key idea is that sunlight is essential for photosynthesis, which produces carbohydrates that serve as energy reserve (stored as starch).
- The plant in dark exhausts its stored starch through respiration with no way to replenish it — this is the direct cause of death.
- Mention both: no photosynthesis → no food/energy to get full marks. Saying only "no sunlight" without linking to energy/food loss will lose a mark.