All of the following statements are incorrect for guard cells, except

Options

A. They are bean-shaped in grasses
B. Non green cells
C. They do not enclose a stomatal pore
D. Their outer wall are thin and inner wall are thick

Answer

**Step-by-Step Solution:**

1. **Understanding Guard Cells**: Guard cells are specialized cells that surround the stomata (pores) on the surface of leaves and are crucial for regulating gas exchange and transpiration in plants.

2. **Identifying the Statements**: The question states that all the following statements about guard cells are incorrect, except one. We need to analyze each statement to find the correct one.

3. **Analyzing the Statements**:
- **Statement 1**: "They are all bean-shaped in grasses."
- This is incorrect because guard cells in monocots (like grasses) are typically dumbbell-shaped, while in dicots, they are bean-shaped.

- **Statement 2**: "They are non-green cells."
- This is incorrect as guard cells contain chloroplasts, which are green and involved in photosynthesis.

- **Statement 3**: "They do not enclose the stomatal pore."
- This is incorrect because guard cells actually form the stomatal pore and control its opening and closing.

- **Statement 4**: "The outer walls are thin and the inner walls are thick."
- This statement is correct. In guard cells, the outer walls are indeed thinner compared to the inner walls, which are thicker. This structural difference helps in the functioning of the guard cells.

4. **Conclusion**: The only correct statement about guard cells is that the outer walls are thin and the inner walls are thick.

**Final Answer**: The correct statement about guard cells is: "The outer walls are thin and the inner walls are thick."

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