Answer: oxygen.
- A oxygen
- B nitrogen
- C water
- D glucose
Correct answer: A. oxygen
Explanation: At high O₂/low CO₂, RuBisCO fixes oxygen, starting the wasteful photorespiration pathway.
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.