Osmotic potential and pressure potential of three cells , a,b,s located in different parts of an actively transpiring plant are
`{:("Cell","O.P (MPa)", "P.P(MPa)"),(a,-0.87,0.44),(b,-0.92,0.34),(c,-0.68,0.27):}`
which ones are roots hair , root cortical and mesophyll cells respectively

Options

A. a,b,c
B. a,c,b
C. c,a,b
D. b,c,a

Answer

To determine which cells correspond to root hairs, root cortical cells, and mesophyll cells based on their osmotic potential (O.P) and pressure potential (P.P), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Parameters**:
- Osmotic Potential (O.P) indicates the tendency of water to move into a cell. A more negative value means a higher tendency for water to enter.
- Pressure Potential (P.P) indicates the pressure exerted by the cell contents against the cell wall. A higher pressure potential can counteract osmotic potential.

2. **Calculate Water Potential (Ψw)**:
The water potential (Ψw) can be calculated using the formula:
\[ Ψw = O.P + P.P \]
We will calculate Ψw for each of the three cells.

3. **Calculate Ψw for Each Cell**:
- For Cell A:
\[ Ψw_a = -0.87 + 0.44 = -0.43 \, \text{MPa} \]
- For Cell B:
\[ Ψw_b = -0.92 + 0.34 = -0.58 \, \text{MPa} \]
- For Cell C:
\[ Ψw_c = -0.68 + 0.27 = -0.41 \, \text{MPa} \]

4. **Interpret the Results**:
- The cell with the least negative water potential (highest Ψw) typically corresponds to the root hairs, as they are actively taking up water.
- The root cortical cells will have a moderate water potential, and the mesophyll cells will have the most negative water potential due to transpiration.

5. **Assign the Cells**:
- **Cell A** (Ψw = -0.43 MPa): This cell has the highest water potential, so it is likely the **root hair cell**.
- **Cell B** (Ψw = -0.58 MPa): This cell has a moderate water potential, making it the **root cortical cell**.
- **Cell C** (Ψw = -0.41 MPa): This cell has the lowest water potential, indicating it is the **mesophyll cell**.

### Conclusion:
- Cell A: Root Hair
- Cell B: Root Cortical
- Cell C: Mesophyll

### Final Answer:
- The correct assignments are:
- Cell A: Root Hair
- Cell B: Root Cortical
- Cell C: Mesophyll