- A Sodium
- B Magnesium
- C Calcium
- D Potassium
Correct answer: B. Magnesium
Explanation: Chlorophyll has magnesium (Mg) at its center. Magnesium deficiency causes yellowing (chlorosis) in plants.
Concept context
Light reactions, the Calvin cycle, C3/C4/CAM pathways, photorespiration, and factors affecting the rate of photosynthesis. One of the highest-yield NEET chapters.