Formula for Water Potential

Q. If a plant cell’s 𝜳p = 2 bars and its 𝜳s = -3.5 bars, what is the resulting 𝜳w?

1. 0
2. -1.5 bars
3. 1.5 bars
4. 5.5 bars

Q. The solute potential of a plant cell is -17 bar and its pressure potential is 5 bar. The plant cell is placed in a solution with a water potential of -12 bar. Determine the water potential and the flow of water.

1. -12 bar; water will move into the cell
2. -12 bar; there will be no net movement of water
3. -22 bar; water will move out of the cell
4. -22 bar; water will move into the cell

Q. Cell A and cell B are adjacent plant cells. In cell A, ${\Psi }_s=-20\text{bars}$ and ${\Psi }_p=8\text{bars}$. In cell B, ${\Psi }_s=-12\text{bars}$ and ${\Psi }_p=2\text{bars}$. Then

1. Water moves from cell B to cell A.
2. Equal amount of water is simultaneously exchanged between cell A and cell B.
3. There is no movement of water between cell A and cell B.
4. Water moves from cell A to cell B.

Q.

The two main components that determine water potential are

1. Solute potential

2. Pressure potential

3. Suction pressure

4. Both solute & pressure potential

Q. The increase in water potential due to positive hydrostatic pressure is called

1. Solute potential

2. Pressure potential

3. Osmotic potential

4. Osmotic pressure

Q.

Study the following table showing the components of water potential of four cells of an actively transpiring plant.
$\begin{array}{ccc}Cell& Solutepotential& Pressurepotential\\ & \left(MPa\right)& \left(MPa\right)\\ A& -0.68& 0.42\\ B& -0.75& 0.36\\ C& -0.83& 0.47\\ D& -0.57& 0.29\end{array}$
Identify the four cells as root hair, cortical cell, endodermal cell (lacking casparian strips) and pericycle cell respectively in the young root (assuming symplastic water flow through them).

1. B, D, C, A

2. D, A, C, B

3. A, D, C, B

4. A, C, B, D

Q. Which of the following statements is wrong?

1. Solute potential is always negative.
2. Pressure potential is zero in flaccid cell.
3. Water potential equals solute potential in a fully turgid cell.
4. Water potential is the chemical potential of the water.

Q.

The two main components that determine water potential are

1. Solute potential

2. Pressure potential

3. Suction pressure

4. Both a & b

Q. If you ignore the factors which are negligible and universal, which are the main components that determine water potential?

1. Pressure potential
2. Gravity potential
3. Matrix potential
4. Solute potential

Q. If a hypothetical cell A with diffusion pressure deficit (DPD) 3 bars is connected to three cells B, C, D whose osmotic potential (OP) and total pressure (TP) are respectively 4 and 4, 10 and 6 and 7 and 2 bars, the flow of water will be

1. A and D to B and C
2. A to B, C and D
3. B to A, C and D
4. C to A, B and D

Q.

What would be the Pressure Potential (due to turgor pressure) of a plasmolyzed cell, flaccid cell and a swollen cell? Can Pressure Potential ever be negative?

Q. If a plant cell’s 𝜳p = 2 bars and its 𝜳s = -3.5 bars, what is the resulting 𝜳w?

1. \N
2. -1.5 bars
3. 1.5 bars
4. 5.5 bars

Q. Solute potential is

1. decrease in magnitude of 𝚿w due to the dissolution of solute
2. Magnitude of change in the 𝚿w due to the mechanical pressure
3. Component of 𝚿w contributed by the application of pressure by the solution
4. Pressure exerted by the protoplast due to the entry of water into the cell

Q. In a fully turgid plant cell, which one is zero?

1. Turgor pressure
2. DPD
3. None of the above
4. Wall pressure

Q. The cell is fully turgid when

1. OP $=$ DPD
2. DPD $=$ TP
3. DPD $=$ SP
4. DPD $=$ zero

Q. In a fully turgid cell, which one of the following is zero?

1. SP
2. None of the above
3. OP
4. TP

Q. Identify the correct option with reference to water potential.

1. ${\psi }_w={\psi }_s+{\psi }_p$
2. ${\psi }_w={\psi }_s-{\psi }_p$
3. ${\psi }_s={\psi }_p+{\psi }_w$
4. ${\psi }_p={\psi }_s+{\psi }_w$

Q. In a fully turgid cell, the values of DPD, OP and TP should be

1. DPD $=$ 10 atm, OP $=$ 15 atm, TP $=$ 5 atm
2. DPD $=$ 2 atm, OP $=$ 7 atm, TP $=$ 5 atm
3. DPD $=$ 5 atm, OP $=$ 12 atm, TP $=$ 7atm
4. DPD $=$ 0 atm, OP $=$ 15 atm, TP $=$ 15 atm

Q. Two cells A and B are contiguous. Cell A has osmotic pressure 10 atm, turgor pressure - 7 atm and diffusion pressure deficit 3 atm. Cell B has osmotic pressure 8 atm, turgor pressure - 3 atm and diffusion pressure deficit 5 atm. The result will be

1. Movement of water from cell B to A.
2. No movement of water.
3. Equilibrium between the two.
4. Movement of water from cell A to B.

Q. Explain the components of water potential.

Q. If cell A with DPD 4 bars is conected to cell B, C, D, whose osmotic pressure and turgor pressure are respectively 4 and 4; 10 and 5; 7 and 3 bar, the flow of water will be

1. A to B, C and D
2. A to D, B and C
3. B to A, C and D
4. C to A, B and D

Q.

Two cells, A and B beside each other in the root cortex. ${\psi }_s$ and ${\psi }_p$ values of cell A are - 0.8 MPa and 0.6 MPa. ${\psi }_s$ and ${\psi }_p$ of cell B are -0.7MPa and 0.4 MPa. Water moves from ______.

1. B to A

2. Dynamic Equilibrium between A and B

3. No movement

4. A to B

Q. If you ignore the factors which are negligible and universal, which are the main components that determine water potential?

1. Pressure potential
2. Gravity potential
3. Matrix potential
4. Solute potential

Q. Why hygroscopic water is not available to plants?

1. Because its ${\Psi }_w$ is greatly increased
2. Because its DPD is greatly decreased
3. Because its ${\Psi }_w$ becomes strongly negative
4. Because its ${\Psi }_w$ is increased and DPD is decreased

Q. Water is absorbed by root hairs when

1. Concentration of solute in cell sap is high.
2. They are separated from soil by permeable membrane.
3. Concentration of salt in the soil is high.
4. The plant is rapidly respiring.

Q. Define : Root pressure / Transpiration pull / Cohesion / Vital theories.

Q. If a hypothetical cell A with diffusion pressure deficit (DPD) 3 bars is connected to three cells B, C, D whose osmotic potential (OP) and total pressure (TP) are respectively 4 and 4, 10 and 6 and 7 and 2 bars, the flow of water will be

1. A and D to B and C
2. A to B, C and D
3. B to A, C and D
4. C to A, B and D

Q. Osmotic potential (${\psi }_S$) of a solution is always

1. Positive
2. Negative
3. Zero
4. Variable

Q.

Two cells, A and B beside each other in the root cortex. ${\psi }_s$ and ${\psi }_p$ values of cell A are - 0.8 MPa and 0.6 MPa. ${\psi }_s$ and ${\psi }_p$ of cell B are -0.7MPa and 0.4 MPa. Water moves from ______.

1. A to B

2. B to A

3. Dynamic Equilibrium between A and B

4. No movement

Q. Identify the correct option with reference to water potential.

1. ${\psi }_w={\psi }_s+{\psi }_p$
2. ${\psi }_w={\psi }_s-{\psi }_p$
3. ${\psi }_p={\psi }_s+{\psi }_w$
4. ${\psi }_s={\psi }_p+{\psi }_w$