Answer: Sunlight.
- A Warm soil
- B Sunlight
- C Rich nitrogen
- D Still air
Correct answer: B. Sunlight
Explanation: Ingenhousz demonstrated that green plants release oxygen only in sunlight, establishing the need for light.
Simplified photosynthesis diagram: light energy, CO2, and H2O enter the leaf and are converted in the chloroplast into glucose and O2.
Concept context
Light reactions, the Calvin cycle, C 3 /C 4 /CAM pathways, photorespiration, and factors affecting the rate of photosynthesis. One of the highest-yield NEET chapters.