Question

Which of the following components is not a Micronutrient?

(a) Zn^2+

(b) Ca^2+

(c) Na^+

(d) Mg^2+

The question was posed to me in a job interview.

The doubt is from Cell Nutrients in chapter An Overview of Biological Basics & Enzymes of Bioprocess Engineering

Answer 1

Right choice is (d) Mg^2+

To elaborate: Elements used in large quantities by the plant are termed macronutrients, which can be further defined as primary or secondary.  The primary nutrients include nitrogen (N), phosphorus (P), and potassium (K).  These elements contribute to plant nutrient content, function of plant enzymes and biochemical processes, and integrity of plant cells.  Deficiency of these nutrients contributes to reduced plant growth, health, and yield; thus they are the three most important nutrients supplied by fertilizers.  The secondary nutrients include calcium (Ca), magnesium (Mg), and sulfur (S).