Maximum water potential is present in

Options

A. Hypotonic solution
B. Hypertonic solution
C. Isotonic solution
D. Pure water

Answer

To determine where the maximum water potential is present, we need to understand the concept of water potential and the factors that influence it.

### Step-by-Step Solution:

1. **Understanding Water Potential**:
- Water potential (Ψ) is a measure of the potential energy in water, which determines the direction of water movement. It is influenced by two main components: solute potential (Ψs) and pressure potential (Ψp).
- Water potential can be expressed as:
\[ Ψ = Ψs + Ψp \]

2. **Components of Water Potential**:
- **Solute Potential (Ψs)**: This component decreases as solute concentration increases. More solutes mean fewer free water molecules, which lowers the water potential.
- **Pressure Potential (Ψp)**: This is the physical pressure on the water in a system. It can be positive (turgor pressure in plant cells) or negative (tension in xylem).

3. **Comparing Solutions**:
- **Hypotonic Solution**: Has fewer solutes compared to the inside of cells, leading to a higher water potential than the cell.
- **Isotonic Solution**: Has equal solute concentration inside and outside the cell, resulting in no net movement of water.
- **Hypertonic Solution**: Has a higher concentration of solutes compared to the inside of cells, leading to a lower water potential.
- **Pure Water**: Contains no solutes, meaning it has the highest concentration of free water molecules, resulting in the highest water potential.

4. **Conclusion**:
- Among the options provided (hypotonic, hypertonic, isotonic solutions, and pure water), pure water has the maximum water potential because it contains no solutes, allowing for the highest concentration of free water molecules.

### Final Answer:
The maximum water potential is present in **pure water**.