Critical Concentration

Q.

Explain with examples: macronutrients, micronutrients, beneficial nutrients, toxic elements and essential elements.

Q. (a) Moderate decrease or increase of micronutrients causes deficiency and toxicity symptoms respectively.
(b) Excess of manganese causes toxicity of iron, calcium and molybdenum.
(c) A macronutrient is said to be toxic when present below a critical concentration.

1. Only (a) is correct
2. Only (b) is correct
3. (b) and (c) are correct
4. (a) and (c) are correct