Which of the following helps in ascent of sap?

Options

A. Root pressure
B. Transpiration pull
C. Imbibition
D. both (1) and (2)

Answer

To determine which of the following helps in the ascent of sap, let's analyze the options provided:

1. **Understanding Ascent of Sap**:
- The ascent of sap refers to the upward movement of water and minerals from the roots to the aerial parts of the plant (stems and leaves) through the xylem.

2. **Option A: Root Pressure**:
- Root pressure is generated when roots absorb water and minerals from the soil. This absorption creates pressure within the roots that pushes water upward through the xylem to the stems and leaves. Thus, root pressure contributes to the ascent of sap.

3. **Option B: Transpiration Pull**:
- Transpiration is the process of water evaporation from the leaves. As water evaporates, it creates a negative pressure (transpiration pull) in the xylem, which helps to pull water upward from the roots to the leaves. This mechanism also aids in the ascent of sap.

4. **Option C: Imbibition**:
- Imbibition is the process of absorption of water by solid particles, such as seeds or dry wood, and is not directly related to the upward movement of sap. Therefore, it does not help in the ascent of sap.

5. **Option D: Both 1 and 2**:
- Since both root pressure (Option A) and transpiration pull (Option B) contribute to the ascent of sap, this option is correct.

**Conclusion**: The correct answer is **D. Both 1 and 2**.