Which of the following side of wall of guard cells is thick?

Options

A. Outer
B. Inner
C. Sidewall
D. All the three

Answer

**Step-by-Step Solution:**

1. **Understanding Guard Cells**: Guard cells are specialized cells that surround the stomata (pores) in plant leaves and are responsible for regulating gas exchange and transpiration.

2. **Identifying the Structure**: Each guard cell has two sides: an outer side and an inner side. The guard cells can change shape to open or close the stomata.

3. **Analyzing the Thickness**:
- The **outer side** of the guard cells is generally thinner. This allows for flexibility and movement.
- The **inner side** of the guard cells is thicker. This thickness is crucial as it helps the guard cells to change shape effectively, allowing the stomata to open and close.

4. **Evaluating the Options**:
- **Option 1: Outer Side** - This is incorrect as the outer side is thin.
- **Option 2: Inner Side** - This is correct because the inner side is thick.
- **Option 3: Sidewalls** - This is also incorrect since the sidewalls are thin.

5. **Conclusion**: The correct answer is **Option 2: Inner Side** of the guard cells is thick.

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