The most dominant role in the absorption of water is that of

Options

A. Active absorption
B. Passive absorption
C. Both passive and active absorption
D. None of the above

Answer

**Step-by-Step Solution:**

1. **Understanding Water Absorption in Plants**: Water absorption in plants is crucial for their survival and is primarily done through the roots. There are two main processes involved in water absorption: passive absorption and active absorption.

2. **Defining Passive Absorption**: Passive absorption occurs when water moves from an area of higher concentration (in the soil) to an area of lower concentration (inside the plant roots) without the use of energy. This movement is driven by the concentration gradient.

3. **Mechanisms of Passive Absorption**: Passive absorption can occur through two main mechanisms:
- **Simple Diffusion**: Water molecules move directly through the cell membranes from an area of higher concentration to an area of lower concentration.
- **Facilitated Diffusion**: Water molecules pass through specialized protein channels in the cell membrane, again moving from high to low concentration.

4. **Defining Active Absorption**: In contrast, active absorption requires energy (in the form of ATP) to move water against its concentration gradient, from an area of lower concentration to an area of higher concentration. This process is less dominant compared to passive absorption.

5. **Conclusion**: Given that passive absorption does not require energy and is the primary method by which plants absorb water, the correct answer to the question is that the most dominant role in the absorption of water is that of **passive absorption**.

**Final Answer**: The most dominant role in the absorption of water is that of **passive absorption**.

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