Which of the following essential elements plays an important role in opening and closing of stomata?

Options

A. Mg
B. K
C. Mn
D. P

Explanation

**Step-by-Step Solution:**

1. **Understanding Stomata**: Stomata are small openings found on the surface of leaves that facilitate gas exchange. Each stoma is surrounded by two specialized cells known as guard cells.

2. **Role of Guard Cells**: The guard cells control the opening and closing of the stomata. When the guard cells take up water and swell, they bend away from each other, causing the stomatal pore to open. Conversely, when they lose water, they become flaccid, and the pore closes.

3. **Essential Elements for Stomatal Function**: Various essential elements are involved in the physiological processes of plants, including the opening and closing of stomata.

4. **Identifying the Key Element**: Among the essential elements, potassium (K) plays a crucial role in the functioning of guard cells. It is involved in the osmotic regulation that leads to the movement of water into and out of the guard cells.

5. **Conclusion**: Therefore, the essential element that plays an important role in the opening and closing of stomata is potassium.

**Final Answer**: Potassium (K) is the correct answer.

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