Question

Choose the incorrect pair.

\[ \begin{array}{|c|l|l|} \hline \text{Element} & & \text{Role} \\ \hline \text{A} & \text{Zinc} & \text{Auxin synthesis} \\ \hline \text{B} & \text{Nickel} & \text{Activator of urease} \\ \hline \text{C} & \text{Molybdenum} & \text{Component of nitrogenase} \\ \hline \text{D} & \text{Manganese} & \text{Activator of catalase} \\ \hline \end{array} \]

• A. A
• B. B
• C. C
• D. D

Hint:

Important micronutrients: \[ \boxed{ \begin{aligned} &\text{Zn} &&\rightarrow \text{Auxin synthesis}, &\text{Ni} &&\rightarrow \text{Urease activator}, &\text{Mo} &&\rightarrow \text{Nitrogenase component}, &\text{Fe} &&\rightarrow \text{Catalase and cytochromes}. \end{aligned} } \]

Answer 1

The Correct Option is D

Step 1: Recall the functions of mineral elements. \[ \begin{aligned} \text{Zinc} &\rightarrow \text{Auxin synthesis}, \text{Nickel} &\rightarrow \text{Activator of urease}, \text{Molybdenum} &\rightarrow \text{Component of nitrogenase}. \end{aligned} \] All these pairs are correct.

Step 2: Examine the role of manganese. Manganese acts as an activator of several enzymes involved in respiration and photosynthesis. Catalase, however, contains iron as its prosthetic group and is not activated by manganese. Therefore, \[ \boxed{\text{Manganese } \rightarrow \text{Activator of catalase}} \] is an incorrect pair.

Step 3: Choose the correct option. Hence, the incorrect pair is \[ \boxed{(D).} \]