The continuity of water column in xylem is maintained due to

Options

A. Root pressure
B. Cohessive property of water
C. Transpiratory pull
D. All the above

Answer

To answer the question about what maintains the continuity of the water column in xylem, we can break down the explanation into several steps:

### Step-by-Step Solution:

1. **Understanding Xylem Function**:
- Xylem is a type of vascular tissue in plants responsible for the transport of water and nutrients from the roots to the leaves.

2. **Identifying Factors Affecting Water Column**:
- The continuity of the water column in xylem can be influenced by several factors, including root pressure, cohesive forces between water molecules, and transpiration pull.

3. **Exploring Cohesive Property of Water**:
- Cohesion refers to the attractive force between water molecules. This property allows water molecules to stick together, forming a continuous column of water in the xylem vessels.

4. **Role of Adhesive Forces**:
- Adhesion is the force between water molecules and the walls of the xylem vessels. While this helps in the upward movement of water, it is the cohesive forces that primarily maintain the continuity of the water column.

5. **Understanding Transpiratory Pull**:
- Transpiratory pull is the force generated by the evaporation of water from the leaves, which creates a negative pressure in the xylem, helping to pull water upward. This also contributes to maintaining the water column.

6. **Evaluating the Options**:
- Option A (Root pressure) contributes to water movement but is not the primary factor for continuity.
- Option B (Cohesive property of water) is crucial for maintaining the water column.
- Option C (Transpiratory pull) also plays a role but is not the sole factor.
- Option D (All the above) suggests that all factors contribute, but the question specifically asks for the primary reason.

7. **Conclusion**:
- The primary factor that maintains the continuity of the water column in xylem is the cohesive property of water. Therefore, the correct answer is **Option B**.