The lowest water potential is found in the xylem channels of

Options

A. Stem
B. Root
C. Root in the root hair zone
D. Leaves.

Answer

To determine where the lowest water potential is found in the xylem channels of a plant, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Water Potential**: Water potential (Ψ) is a measure of the potential energy in water, which influences the movement of water within plants. It is affected by solute concentration and pressure.

2. **Identify the Components of Water Potential**: Water potential is influenced by two main factors:
- **Solute Potential (Ψs)**: The concentration of solutes in the water. Higher solute concentration results in lower solute potential.
- **Pressure Potential (Ψp)**: The physical pressure on the water. In xylem, this is usually positive due to the tension created by transpiration.

3. **Consider the Locations in the Plant**: The question gives us four options: stem, root, root in the root hair zone, and leaves. We need to analyze each location:
- **Stem**: While stems do transport water, they generally do not have the lowest water potential compared to leaves.
- **Roots**: Roots absorb water from the soil, and while they may have some solute concentration, they typically have a higher water potential than leaves.
- **Root Hair Zone**: This area is involved in water absorption, and while it may have some solute concentration, it is not the lowest.
- **Leaves**: Leaves lose water through transpiration, which increases the solute concentration in the xylem channels.

4. **Role of Transpiration**: Transpiration is the process of water vapor loss from the plant, primarily through stomata in the leaves. This loss of water leads to an increase in solute concentration in the xylem of the leaves.

5. **Conclusion**: As water is lost from the leaves during transpiration, the solute concentration in the xylem increases, resulting in the lowest water potential in the xylem channels of the leaves.

### Final Answer:
The lowest water potential is found in the xylem channels of the **leaves**.

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