The phenomenon related to active water absorption is

Options

A. Transpiration
B. Root pressure
C. Osmotic pressure
D. Translocation

Answer

**Step-by-Step Solution:**

1. **Understanding Active Water Absorption**: Active water absorption refers to the process by which plants take up water from the soil against a concentration gradient, requiring energy (ATP).

2. **Analyzing the Options**:
- **Transpiration**: This is the process of water vapor loss from the leaves of the plant. It does not involve absorption of water; instead, it is a loss of water.
- **Root Pressure**: This is a hydrostatic pressure generated in the roots that helps in the upward movement of water and nutrients from the soil into the plant's vascular system (xylem). This process is related to active water absorption as it involves the movement of water into the roots.
- **Osmotic Pressure**: This refers to the movement of water through a semi-permeable membrane from an area of low solute concentration to high solute concentration. While it is related to water movement, it does not specifically denote active absorption.
- **Translocation**: This is a genetic phenomenon where a segment of a chromosome breaks off and attaches to another chromosome. It is unrelated to water absorption.

3. **Identifying the Correct Answer**: Given the definitions and explanations of each option, root pressure is the phenomenon that directly relates to active water absorption in plants. It helps in driving water and nutrients from the soil into the plant, especially during the night when transpiration is minimal.

4. **Conclusion**: Therefore, the correct answer to the question is **Root Pressure**.

**Final Answer**: Root Pressure (Option 2)

---