Zinc has a role in :

Options

A. `NO_(3)^(-)` reduction
B. Carbonic anhydrase activity
C. sugar translocation
D. Amylase activity

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the role of zinc in plant nutrition. We need to evaluate the given options to identify which one correctly describes the function of zinc.

2. **Evaluating Option A (Nitrate Reduction)**: This option states that zinc is involved in nitrate reduction. However, nitrate reduction is catalyzed by the enzyme nitrate reductase, which requires molybdenum as a cofactor, not zinc. Therefore, this option is incorrect.

3. **Evaluating Option B (Carbonic Anhydrase)**: The second option mentions carbonic anhydrase, which is a metalloenzyme that contains zinc at its active site. This enzyme plays a crucial role in acid-base balance and is important for various physiological processes. Since zinc is indeed involved in the functioning of carbonic anhydrase, this option is correct.

4. **Evaluating Option C (Sugar Translocation)**: The third option refers to sugar translocation, which is primarily facilitated by boron, not zinc. Boron is essential for the translocation of sugars in plants. Hence, this option is incorrect.

5. **Evaluating Option D (Amylase Activity)**: The fourth option discusses amylase activity, which is an enzyme involved in starch breakdown. Calcium is known to play a significant role in the activity of amylase, not zinc. Therefore, this option is also incorrect.

6. **Conclusion**: After evaluating all the options, the only correct role of zinc is in the activity of carbonic anhydrase. Thus, the correct answer is option B.

**Final Answer**: Zinc has a role in carbonic anhydrase activity.

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