A solution is differ from pure water in having –

Options

A. Low `psi_(w)`
B. Low DPD
C. Low `psi_(p)`
D. Low OP

Answer

To answer the question "A solution is different from pure water in having –", we need to understand the key differences between a solution and pure water, particularly in terms of water potential, solute potential, pressure potential, diffusion pressure deficit, and osmotic pressure.

### Step-by-Step Solution:

1. **Definition of Pure Water**:
- Pure water is a substance that contains no solutes. It has a water potential (Ψw) of zero because it has the highest potential for water movement.

2. **Definition of a Solution**:
- A solution is formed when solutes (substances dissolved in water) are added to pure water. This results in a change in the water potential of the solution.

3. **Water Potential (Ψw)**:
- Water potential in a solution is lower than that of pure water due to the presence of solutes. The presence of solutes lowers the water potential, making it negative.

4. **Solute Potential (Ψs)**:
- The solute potential of a solution is negative and is a measure of the effect of solutes on the potential of water to move. In pure water, the solute potential is zero.

5. **Pressure Potential (Ψp)**:
- In a solution, the pressure potential can vary depending on the physical pressure exerted on the solution. However, it is generally lower than that of pure water when considering osmotic pressure.

6. **Diffusion Pressure Deficit (DPD)**:
- DPD is the difference between the water potential of pure water and that of the solution. A solution has a higher DPD compared to pure water because the water potential is lower in the solution.

7. **Osmotic Pressure (OP)**:
- Osmotic pressure is directly related to the concentration of solutes in the solution. A solution has a higher osmotic pressure than pure water due to the presence of solutes.

### Conclusion:
A solution differs from pure water primarily in having a lower water potential, a negative solute potential, a higher osmotic pressure, and a higher diffusion pressure deficit.