Which of the following pair is correct ?

Options

A. Mn - formation of chlorophyll
B. P - required in meristematic tissues
C. Ca - formation of the mitotic spindle
D. Cu - synthesis of auxin

Answer

To solve the question regarding which pair of plant nutrients and their functions is correct, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Understand Plant Nutrients**:
- Plant nutrients are categorized into two main types: macronutrients and micronutrients.
- Macronutrients are required in larger amounts, while micronutrients are needed in smaller quantities.

2. **Identify Macronutrients and Micronutrients**:
- **Macronutrients**: Nitrogen, Phosphorus, Potassium, Calcium, Magnesium.
- **Micronutrients**: Zinc, Boron, Nickel, Manganese, etc.

3. **Evaluate Each Option**:
- **Option 1: Manganese - Formation of Chlorophyll**:
- Incorrect. Manganese is involved in nitrogen metabolism and the splitting of water during photosynthesis, not directly in chlorophyll formation.

- **Option 2: Phosphorus - Merismatic Tissue**:
- Incorrect. Potassium is required in merismatic tissue for cell division, not phosphorus.

- **Option 3: Calcium - Formation of Mitotic Spindle**:
- Correct. Calcium is a macronutrient that plays a role in cell division and the formation of the mitotic spindle.

- **Option 4: Copper - Synthesis of Auxin**:
- Incorrect. The synthesis of auxin is primarily associated with zinc, not copper.

4. **Conclusion**:
- The only correct pair is **Calcium - Formation of Mitotic Spindle**.

### Final Answer:
The correct pair is **Calcium - Formation of Mitotic Spindle**.

---