Which of the following nutrients is incorrectly paired with its function in a plant?

Options

A. Calcium-formation of cell walls, combines with pectin to glue cells together
B. Magnesium-constituent of chlorophyll, cofactor for important enzymes
C. Iron component of chlorophyll
D. Potassium-Important in osmotic regulations, cofactor

Answer

To determine which nutrient is incorrectly paired with its function in a plant, we will analyze each option provided.

### Step-by-Step Solution:

1. **Identify the Nutrients and Their Functions**:
- We need to look at the nutrients listed and their corresponding functions to see if they are accurately paired.

2. **Evaluate Calcium**:
- **Function**: Calcium helps in the formation of the cell wall by combining with pectin and glucose.
- **Analysis**: This statement is correct. Calcium is indeed crucial for the structural integrity of plant cell walls.

3. **Evaluate Magnesium**:
- **Function**: Magnesium is a constituent of chlorophyll and acts as a cofactor for important enzymes.
- **Analysis**: This statement is also correct. Magnesium is essential for chlorophyll formation and plays a role in photosynthesis.

4. **Evaluate Iron**:
- **Function**: Iron is a component of chlorophyll.
- **Analysis**: This statement is incorrect. Iron is not a direct component of chlorophyll; rather, it is essential for the formation of chlorophyll. Therefore, this pairing is incorrect.

5. **Evaluate Potassium**:
- **Function**: Potassium acts as an osmotic regulator and is involved in various physiological processes.
- **Analysis**: This statement is correct. Potassium helps in osmoregulation, maintaining turgidity, and regulating stomatal opening and closing.

6. **Conclusion**:
- The nutrient that is incorrectly paired with its function is **Iron**, as it is not a component of chlorophyll but is necessary for its formation.

### Final Answer:
The incorrectly paired nutrient with its function is **Iron**.

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