The relationship of DPD , OP , TP and WP is

Options

A. DPD=OP-TP(WP)
B. DPD=-OP+TP(WP)
C. DPD=OP+TP(WP)
D. DPD=-OP-WP(TP )

Answer

To understand the relationship between DPD (Diffusion Pressure Deficit), OP (Osmotic Pressure), TP (Turgor Pressure), and WP (Wall Pressure), we can break it down step by step:

### Step-by-Step Solution:

1. **Definitions**:
- **DPD (Diffusion Pressure Deficit)**: It is the reduction in the diffusion pressure of water in a solution or cell compared to its pure state due to the presence of solutes. It indicates the actual thrust of a cell for water.
- **OP (Osmotic Pressure)**: This is the pressure required to prevent the flow of solvent molecules through a semi-permeable membrane. It is the pressure exerted by solutes in a solution.
- **TP (Turgor Pressure)**: This is the pressure exerted by the fluid (cytoplasm) against the cell wall when water enters the cell, causing it to swell.
- **WP (Wall Pressure)**: This is the pressure exerted by the cell wall against the turgor pressure of the cell.

2. **Understanding Relationships**:
- When a cell is fully turgid (swollen with water), the osmotic pressure (OP) equals the turgor pressure (TP). At this point, the cell does not absorb any more water, which means the DPD is zero.
- The relationship can be expressed mathematically as:
\[ DPD = OP - TP \]
- Since turgor pressure (TP) is equal to wall pressure (WP) in a turgid cell, we can also express the relationship as:
\[ DPD = OP - WP \]

3. **Conclusion**:
- Therefore, the correct relationship among DPD, OP, TP, and WP is:
\[ DPD = OP - TP \quad \text{(or)} \quad DPD = OP - WP \]
- The correct option from the given choices is that DPD equals OP minus TP (or wall pressure).

### Final Answer:
The relationship of DPD, OP, TP, and WP is:
\[ DPD = OP - TP \quad \text{(or)} \quad DPD = OP - WP \]