Root pressure can be responsible for

Options

A. pushing up water to small heights in the stem.
B. active transport of various ions into the vascular tissues of the roots
C. absorption of water into the vascular tissues of the roots
D. development of transpiration pull

Answer

### Step-by-Step Solution:

1. **Understanding Root Pressure**:
- Root pressure is the pressure exerted in the xylem of the roots due to the accumulation of water and solutes. It occurs when water is absorbed by the roots from the soil, leading to an increase in pressure within the xylem vessels.

2. **Role of Active Transport**:
- The roots actively transport various ions from the soil into the vascular tissue. This process is essential for nutrient uptake but is not directly caused by root pressure.

3. **Water Movement**:
- As ions are actively transported into the vascular tissue, water follows these solutes due to osmosis. This movement of water increases the pressure in the xylem, contributing to root pressure.

4. **Function of Root Pressure**:
- Root pressure is primarily responsible for pushing water upward to small heights in the stem. It is effective in moving water a limited distance, mainly in herbaceous plants.

5. **Transpiration Pull**:
- While root pressure can assist in water movement, the main mechanism for water transport in plants is transpiration pull, which occurs due to the evaporation of water from the leaves.

6. **Evaluating the Options**:
- Given the options:
- **Pushing of water to small heights in the stem**: This is correct as root pressure can indeed push water upward.
- **Active transport of various ions into the vascular tissue of the roots**: This is incorrect; root pressure does not cause active transport.
- **Absorption of water into the vascular tissue of the roots**: This is also incorrect; absorption is a separate process.
- **Development of transpiration pull**: This is incorrect; transpiration pull is primarily due to evaporation from leaves, not root pressure.

7. **Conclusion**:
- The correct answer is that root pressure is responsible for the **pushing of water to small heights in the stem**.