Exudation of xylem sap on cutting of a shoot is due to

Options

A. Guttation
B. Root pressure
C. Transpiration
D. None of the above

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the phenomenon of xylem sap exudation when a shoot is cut. We need to identify the underlying cause of this exudation from the given options.

2. **Reviewing the Options**: The options provided are:
- A) Guttation
- B) Root pressure
- C) Transpiration
- D) None of the above

3. **Analyzing Guttation**:
- Guttation refers to the process where water droplets are secreted from the pores of leaves, particularly at night or in high humidity conditions. It is not directly related to the cutting of a shoot and does not explain xylem sap exudation in this context.

4. **Analyzing Root Pressure**:
- Root pressure is the pressure exerted by the roots of a plant that helps in pushing water and dissolved nutrients upward through the xylem. When a shoot is cut, the pressure built up in the roots can cause xylem sap to exude from the cut surface.

5. **Analyzing Transpiration**:
- Transpiration is the process of water vapor loss from the aerial parts of the plant, primarily through stomata in the leaves. While it plays a role in water movement, it does not directly cause sap exudation when a shoot is cut.

6. **Conclusion**: Based on the analysis, the correct answer is **B) Root pressure**. The exudation of xylem sap on cutting of a shoot is primarily due to the root pressure that pushes the sap upward.

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