Deficiency of which of the following can cause urea accumulation.

Options

A. Calcium
B. copper
C. Nickel
D. Phosphorus

Answer

**Step-by-Step Solution:**

1. **Understanding Nutrient Classification**:
- In plants, essential nutrients are classified into two categories: macronutrients and micronutrients. Macronutrients are required in larger quantities, while micronutrients are needed in smaller amounts.

2. **Identifying the Role of Micronutrients**:
- Micronutrients play crucial roles in various physiological processes in plants. One such micronutrient is nickel.

3. **Function of Nickel**:
- Nickel is an essential component of the enzyme urease, which is involved in the breakdown of urea into ammonia and carbon dioxide. This process is vital for nitrogen metabolism in plants.

4. **Consequences of Nickel Deficiency**:
- When there is a deficiency of nickel, the activity of the urease enzyme is impaired. As a result, the breakdown of urea is hindered, leading to its accumulation in the plant.

5. **Conclusion**:
- Therefore, the deficiency of nickel can cause urea accumulation in plants. The correct answer to the question is nickel.

**Final Answer**: Nickel (Option 3) is the element whose deficiency can cause urea accumulation.

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