Question

Which of the following is not a correct pairing of a macronutrient and the major functions it performs in the life of a plant?

• A. Potassium–enzyme activation, water balance, ion balance
• B. Calcium–activity of membranes and cytoskeleton, second messenger
• C. Sulphur–in proteins and coenzymes
• D. Iron–in active sites of many redox enzymes and electron carriers

Answer 1

The correct option is D Iron–in active sites of many redox enzymes and electron carriers

The primary macronutrients are nitrogen (N), phosphorus (P), potassium (K) and the three secondary macronutrients are calcium (Ca), sulfur (S), magnesium (Mg).

The micronutrients/trace minerals are boron (B), chlorine (Cl), manganese (Mn), iron (Fe), zinc (Zn), copper (Cu), molybdenum (Mo), nickel (Ni).

Iron is absorbed mostly in the form of ferric ions by plants and is necessary for cell division and development. Assists in the transport of electrons during a variety of metabolic processes. It is necessary for the activation of the catalase enzyme, which is essential for chlorophyll synthesis; it also functions as an oxygen transporter. Iron comes under micronutrients and not under macronutrient.

Potassium is a macronutrient which plays an important role in enzyme activation, water balance and ion balance.

Calcium ion is also a macronutrient which plays an important role in stimulus-response reactions of cells as a second messenger.

Sulfur is the third most abundant mineral and a macronutrient in your body. It is present in methionine and cysteine, which are two of the amino acids you use to make proteins.

So except iron, all the other options potassium, calcium and sulfur are macronutrients and correctly matched. Only iron (Fe) is a micronutrient. So the correct answer is option "d".