Which is not related to transpiration pull

Options

A. Capillarity theory
B. Ascent of sap
C. Cohesive force
D. Adhesive force

Answer

To solve the question "Which is not related to transpiration pull?", we need to analyze each of the provided options in relation to the concept of transpiration pull.

### Step-by-Step Solution:

1. **Understanding Transpiration Pull**:
- Transpiration pull is the process by which water is drawn up from the roots of a plant to the leaves through the xylem. This occurs due to the evaporation of water from the stomata in the leaves, creating a negative pressure that pulls water upward.

2. **Analyzing the Options**:
- **Option A: Capillary Theory**:
- Capillary theory explains the movement of water in narrow spaces due to capillary action. While it involves the movement of water, it is not directly related to the mechanism of transpiration pull, which is primarily driven by evaporation and the resultant pressure changes.
- **Option B: Ascent of Sap**:
- The ascent of sap refers to the upward movement of water and nutrients in the plant. This process is directly caused by transpiration pull, making this option related to it.
- **Option C: Cohesive Force**:
- Cohesion refers to the attraction between similar molecules, such as water molecules. This property is crucial for the formation of a continuous water column in the xylem, which is essential for transpiration pull. Thus, this option is related.
- **Option D: Adhesive Force**:
- Adhesion is the attraction between different types of molecules, such as water molecules and xylem vessel walls. This force helps water to cling to the walls of the xylem, facilitating its upward movement and is also related to transpiration pull.

3. **Conclusion**:
- After analyzing all the options, we find that **Option A: Capillary Theory** is not directly related to transpiration pull, while the other options (ascent of sap, cohesive force, and adhesive force) are all integral to the process.

### Final Answer:
**The option that is not related to transpiration pull is: Capillary Theory.**

---