Tag: transport in plants

Questions Related to transport in plants

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)

Show answer
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

Show answer
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

Show answer
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'

Water potential of plasmolysed cell will be :

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

  1. $\Psi _w = -\Psi _s + \Psi _p$

  2. $\Psi _w = \Psi _p$

  3. $\Psi _w = 0$

  4. $\Psi _w = -\Psi _s - \Psi _p$

Show answer
Correct Option: B

If a cell A with DPD $=5$ bars is connected to cells B, C and D, whose OP and TP are respectively $5$ and $5$, $10$ and $4$, and $8$ and $3$, the flow of water will be _______________.

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

  1. C to A, B and D

  2. A and D to B and C

  3. A to B, C and D

  4. B to A, C and D

Show answer
Correct Option: D
Explanation:

DPD of cell A=5A=5 bars
DPD of cell B=5−5=0B=5−5=0 bars
DPD of cell C=10−4=6C=10−4=6 bars
DPD of cell D=8−3=5D=8−3=5 bars
As cell B has the lowest value of DPD, therefore water will move from cell B to cells A, C and D.

Which one of the following ions is essential for photolysis of water ?
water potential water potential and pressure plant water relation transport in plants biology

  1. Manganese

  2. Zinc

  3. Copper

  4. Boron

Show answer
Correct Option: A
Explanation:

The phenomenon of breaking up of water into hydrogen and oxygen in the illuminated chloroplasts is called photolysis or photocatalytic splitting of water. It can be depicted as: $4H _{2} O \rightleftharpoons 4H^{+} + 4OH^{-}$
   $4OH^{-}\xrightarrow[Mn^{2} + ,Ca^{2} +, CI^{-}]{Oxygen \,\, evolving \,\, complex} 2H _{2}O + O _{2}\uparrow + 4e^- $

Choose the correct answers from the alternatives given.
Water potential of a cell is lowered by the

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

  1. Addition of solutes

  2. Addition of water

  3. Increase in temperature

  4. Decrease in temperature

Show answer
Correct Option: A
Explanation:

Water potential is the measure of the free energy of water which helps in the movement of water between any two systems. Water moves from the point where the water potential is greater to the point where the water potential is less. Addition of solutes decreases the water potential (becomes more negative). Temperature has no effect on water potential. The water potential of pure water is taken as zero. 

Hence, the correct answer is 'Addition of solutes'.

Choose the correct answers from the alternatives given :
Water potential is generally most negative in

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

  1. the soil solution

  2. mesophyll cell walls

  3. xylem sap of roots

  4. xylem sap of leaves

Show answer
Correct Option: B
Explanation:

Water potential is generally most negative in mesophyll cell walls because water evaporates from the mesophyll cells into the air spaces in the leaf. If the air surrounding the leaf has less water vapor than the air in the intercellular spaces, water vapor will leave the leaf through stomata. Order of water to move through the plant from the soil to the air ( a process called transpiration).

W.P root ---> W.P stem ---> W.P leaf ---> W.P atmosphere.
So, the correct option is 'mesophyll cell walls'.