- A Macronutrient
- B Micronutrient
- C Heavy metal
- D Non-essential element
Correct answer: B. Micronutrient
Explanation: Boron is a micronutrient (trace element) essential in small amounts. It is important for pollen germination, cell wall formation, and sugar transport. Deficiency causes death of growing tips.
Concept context
Essential mineral elements, their roles and deficiency symptoms. Nitrogen fixation and soil nutrition.