- A Iron
- B Zinc
- C Magnesium
- D Calcium
Correct answer: C. Magnesium
Explanation: Magnesium (Mg) is the central atom in the chlorophyll molecule. Deficiency of Mg causes interveinal chlorosis (yellowing between veins) especially in older leaves.
Concept context
Essential mineral elements, their roles and deficiency symptoms. Nitrogen fixation and soil nutrition.