Tag: water potential

Questions Related to water potential

Cell A and cell B are adjacent plant cells. In cell A, $\psi s$ = - 20 bars and $\psi _p$ = 8 bars. In cell B, $\psi _s$ = - 12 bars and $\psi _p$ = 8 bars. Then ______________.

water potential water potential and pressure plant water relation transport in plants biology

  1. Water moves from cell A to cell B

  2. There is no movement of water between cell A and cell B

  3. Water moves from cell B to cell A

  4. Equal amount of water is simultaneously exchanged between cell A and cell B

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Correct Option: C

The movement of water into and out of cells is controlled by

water potential water potential and pressure plant water relation transport in plants biology

  1. Water potential

  2. Endosmosis

  3. Exosmosis

  4. Plasmolysis

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Correct Option: A

What is the effect on the value of DPD when the water potential of that cell is increased :-

water potential water potential and pressure plant water relation transport in plants biology

  1. No effect

  2. Increase

  3. Decrease

  4. Firstly increase then decrease

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Correct Option: A

0.5 M sucrose develops a pressure of 15 bars  in an osmometer. Which of the following statement is wrong for such a solution ______________.

water potential water potential and pressure plant water relation transport in plants biology

  1. That its osmotic potential is-15 bars

  2. That its water potential is-15 bars

  3. That its pressure potential is-15 bars

  4. That its osmotic potential is+15 bars

Show answer
Correct Option: C
Explanation:

The pressure potential is usually positive.

So the incorrect option is C.

Pick the CORRECT statement(s) in the following.
I. Increase in solute potential of a solution increases its water potential.
II. Water potential of pure water is taken as zero.

water potential water potential and pressure plant water relation transport in plants biology

  1. I only

  2. II only

  3. Both (I) & (II)

  4. Neither (I) nor (III)

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Correct Option: A

Water moves from a cell with _______ water potential to a cell with _______ water potential.

water potential water potential and pressure plant water relation transport in plants biology

  1. Higher, Lower

  2. Lower, Higher

  3. Less negative, More negative

  4. Both (a) and (b)

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Correct Option: B

Two cells are kept in $1\ M$ solution of sucrose and $1\ M$ solution of $NaCl$. The water potential $(\Psi {m})$ of the cells kept in _______________.

water potential water potential and pressure plant water relation transport in plants biology

  1. sucrose solution will be greater

  2. $NaCl$ solution will be greater

  3. both will be equal

  4. sucrose solution will be lower and $NaCl$ solution would be greater

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Correct Option: A

The concentration of solute in four cells iis 0.4 M. They are placed in four separate containers I, II, III and IV, filled with saline water of concentrations 0.1 M, 0.4 M, 2 M, and 3 M respectively. In which container will the cell swell? 

water potential water potential and pressure plant water relation transport in plants biology

  1. I

  2. II

  3. III

  4. IV

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Correct Option: A
Explanation:

The cell will swell when the concentration of solute is more inside the cell than the surrounding. Here the concentration of solute inside the cell is 0.4 M, and out of given solutions, 0.1 M solution has a lesser concentration of solute. So, the cell which is placed in a 0.1 M solution will swell. This phenomenon is called osmosis.


So the correct answer is 'A'.

Water will move from the root hair through cortex if the water potentials are _________________________.

water potential water potential and pressure plant water relation transport in plants biology

  1. Root hair- $0$, Cortex-$0$, Xylem-$0$

  2. Root hair-$-2$, Cortex-$-1$, Xylem-$0$

  3. Root hair-$0$, Cortex-$-1$, Xylem-$-2$

  4. Root hair-$0$, Cortex-$+1$, Xylem-$+2$

Show answer
Correct Option: C
Explanation:

If a difference in water potential exists between the two regions, spontaneous movement of water will take place, provided the movement can occur between them. The direction of flow will be energetically down hill, that is from the region of higher water potential(root hair) to the region of lower water potential(xylem) via cortex from less negative water potential (e.g., - $1$ kPa) to more negative water potential (e.g., - $2$ kPa).

So, the correct answer is 'Root hair-0,, Cortex-−1, Xylem−2'

Read the following statements and select the correct option.


(i) Pure water has the highest water potential, i.e., zero.
(ii) Process of diffusion does not require any input of energy.
(iii) Water moves from the system containing water at higher water potential to the one having lower water potential.

water potential water potential and pressure plant water relation transport in plants biology

  1. Statements (i) and (ii) are correct

  2. Statements (ii) and (iii) are correct

  3. Statements (i) and (iii) are correct

  4. Statements (i), (ii) and (iii) are correct

Show answer
Correct Option: D
Explanation:

Pure water is with no dissolved solutes hence its potential is highest that is zero, as solute is added to water potential or energy of water becomes negative. Diffusion is movement of substances from their higher potential/energy/concentration to places of lower potential /energy/concentration hence does not require in put of energy.

Water always moves from its higher potential i.e with lower solute potential to its lower potential or higher solute potential by a process called osmosis.
So, the correct answer is 'Statements (i), (ii) and (iii) are correct'