Answer: Fix CO2 at night as malate (stored in vacuole) to reduce water loss during day.
- A Maximize transpirational water loss while ambient humidity is highest
- B Fix CO2 at night as malate (stored in vacuole) to reduce water loss during day
- C Carry out the full light-dependent reactions of photosynthesis under starlight
- D Release oxygen generated by water-splitting at the oxygen-evolving complex
Correct answer: B. Fix CO2 at night as malate (stored in vacuole) to reduce water loss during day
Explanation: CAM plants (cacti, succulents): stomata open at night to fix CO2 (as malate). Stomata closed during hot day to prevent water loss. CO2 released from malate for Calvin cycle during day.
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.