In the cell walls of the guard cells, cellulose microfibrils are oriented

Options

A. Transversely
B. Tangentially
C. Radially
D. Obliquely

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 water loss.

2. **Cell Wall Composition**: The cell walls of guard cells contain cellulose microfibrils, which are fine, fiber-like strands made up of cellulose and glycoproteins.

3. **Orientation of Microfibrils**: The orientation of cellulose microfibrils in the cell walls of guard cells is crucial for their function. The arrangement of these microfibrils affects how the guard cells can change shape.

4. **Radial Orientation**: In guard cells, the cellulose microfibrils are oriented radially. This means they are arranged in a way that allows the guard cells to expand and contract effectively, facilitating the opening and closing of the stomatal pore.

5. **Importance of Radial Orientation**: The radial arrangement of microfibrils is essential for the proper functioning of stomata. When guard cells take up water and become turgid, the radial orientation helps them to swell and open the stomatal pore.

6. **Conclusion**: Based on the orientation of cellulose microfibrils in guard cells, the correct answer to the question is that they are oriented **radially**.

### Answer: Radially (Option 3)

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