The actual pressure with which water enters into the cell is called

Options

A. (a) DPD has negative and `Psi_(W)` has positive value.
B. (b) Osmotic potential
C. (c) Water potential
D. (d) Diffusion

Answer

To solve the question "The actual pressure with which water enters into the cell is called," we can break down the concepts involved step by step.

### Step-by-Step Solution:

1. **Understanding Water Movement in Cells**:
- Water enters plant cells primarily through osmosis, which is the movement of water from an area of higher water potential to an area of lower water potential.

2. **Defining Key Terms**:
- **Osmotic Pressure**: This is the pressure required to prevent water from moving across a semipermeable membrane. It is influenced by the concentration of solutes in the solution.
- **Turgor Pressure**: This is the pressure exerted by the fluid (water) inside the cell against the cell wall. It develops when water enters the cell.

3. **Diffusion Pressure Deficit (DPD)**:
- DPD is defined as the difference between the osmotic pressure of the solution and the turgor pressure of the cell. It indicates the actual pressure with which water enters the cell.
- The formula for DPD can be expressed as:
\[ \text{DPD} = \text{Osmotic Pressure} - \text{Turgor Pressure} \]
- DPD is also referred to as suction pressure, as it reflects the tendency of water to move into the cell.

4. **Water Potential**:
- Water potential is a measure that combines both osmotic potential and pressure potential. It is generally expressed as:
\[ \text{Water Potential} = \text{Osmotic Potential} + \text{Pressure Potential} \]
- In plant cells, water potential is usually positive, while DPD is negative due to the reduction in free energy of water as it enters the cell.

5. **Conclusion**:
- The actual pressure with which water enters the cell is referred to as **Diffusion Pressure Deficit (DPD)**. This is the correct answer to the question.

### Final Answer:
The actual pressure with which water enters into the cell is called **Diffusion Pressure Deficit (DPD)**.

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