Most critical element for plant growth is

Options

A. Mg
B. N
C. Fe
D. Cu

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the most critical element for plant growth among the given options: Magnesium, Nitrogen, Iron, and Copper.

2. **Identifying the Options**:
- A: Magnesium
- B: Nitrogen
- C: Iron
- D: Copper

3. **Analyzing Each Element**:
- **Magnesium**: It is important for chlorophyll production and enzyme activation but is not the most critical element.
- **Nitrogen**: It is a macronutrient and is essential for the synthesis of proteins, nucleic acids, vitamins, and hormones. It is absorbed mainly as nitrate ions and is crucial for meristematic tissues and metabolically active cells.
- **Iron**: It is essential for chlorophyll synthesis and enzyme functions but is required in smaller amounts compared to nitrogen.
- **Copper**: It plays a role in photosynthesis and enzyme activity but is also needed in trace amounts.

4. **Determining the Most Critical Element**:
- Nitrogen is the most abundant macronutrient in plants and is required in large quantities for various vital functions. It is essential for every part of the plant, especially in meristematic tissues and metabolically active cells.

5. **Conclusion**: Based on the analysis, the most critical element for plant growth is **Nitrogen** (Option B).

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