Tag: plant water relation

Questions Related to plant water relation

Which of the following equation is correct for incipient plasmolysed cell ?

botany plant water relation diffusion pressure deficit other pressure components osmosis in plants

  1. $DPD=OP-TP$

  2. $OP=TP$

  3. ${ \Psi } _{ w }={ \Psi } _{ s }+{ \Psi } _{ p }$

  4. ${ \Psi } _{ w }={ \Psi } _{ s }-{ \Psi } _{ p }$

Show answer
Correct Option: C
Explanation:

Diffusion pressure deficit - It is described as the ability of water to move is used to measure in terms of diffusion pressure. 


(C) $\Psi _w = \Psi _s + \Psi _p$

The point during which the protoplast is just pulled or moved away from the cell wall is called incipient plasmolysis.

Which cell has maximum diffusion pressure deficit?

botany plant water relation diffusion pressure deficit other pressure components osmosis in plants

  1. Flacid cell

  2. Turgid cell

  3. Prokaryotic cell

  4. Eukaryotic cell

Show answer
Correct Option: A
Explanation:

Diffusion pressure deficit or DPD is the difference between the pressure of a solution and a pure solvent. It is also called as suction pressure. In order to achieve the equilibrium or attain zero value of DPD, the solvent from low solute concentration or low DPD to high solute concentration or high DPD. In other words, the diffusion pressure deficit is equal to the total of osmotic pressure and turgor pressure. DPD is maximum in pure water. In a flaccid cell, there is no movement of water. In a flaccid cell, there is no turgor pressure. Hence, DPD is equal to the osmotic pressure.

Thus, the correct answer is 'Flaccid cell.'

Find out the incorrect about diffusion pressure(DP)
I. DP $\alpha$ Conc. of solution
II. DP $=$ DP
III. For a fully turgid cell, DP$=0$.

botany plant water relation diffusion pressure deficit other pressure components osmosis in plants

  1. I and II only

  2. II & III only

  3. I & III only

  4. I, II and III

Show answer
Correct Option: A

Pressure exerted by cell wall to balance turgor pressure is called

botany plant water relation diffusion pressure deficit other pressure components osmosis in plants

  1. Wall pressure

  2. DPD

  3. Water potential

  4. Osmotic pressure

Show answer
Correct Option: A
Explanation:

'Wall pressure' is the pressure exerted by the cell wall to balance turgor pressure.

When a cell is placed in water, it takes in water due to

botany plant water relation diffusion pressure deficit other pressure components osmosis in plants

  1. Osmotic pressure

  2. Suction pressure

  3. Translocation

  4. Water potential and TP

Show answer
Correct Option: B
Explanation:

'Diffusion pressure deficit' (DPD) is also known as suction pressure (SP). DPD is responsible for movement of water in a plant. Water moves from a region or cell of low DPD to a cell or region of high DPD. The DPD is calculated as the difference of osmotic pressure (which is responsible for entry of water into a cell) and turgor pressure (which opposes entry of water into a cell). 

Water enters from the soil into the root hairs due to

botany plant water relation diffusion pressure deficit other pressure components osmosis in plants

  1. Turgor pressure of root hair

  2. Osmotic pressure of root hair

  3. Suction pressure

  4. Diffusion pressure

Show answer
Correct Option: C
Explanation:

Suction pressure is same as DPD (Diffusion Pressure Deficit). Water moves in a plant due to suction pressure or DPD from a region of lower DPD to a region of higher DPD.

The term diffusion pressure deficit was coined by 

botany plant water relation diffusion pressure deficit other pressure components osmosis in plants

  1. De Duve

  2. B.S Meyer

  3. Novikoff

  4. None of the above

Show answer
Correct Option: B
Explanation:

The term diffusion pressure deficit (DPD) was coined by B.S Meyer in 1938. 

The amount by which diffusion pressure of a solution is lower than its pure solvent is known as Diffusion Pressure Deficit. DPD of pure water is the lowest. Hence option B is correct.

What will be zero in fully turgid cell ________.

botany plant water relation diffusion pressure deficit other pressure components osmosis in plants

  1. TP

  2. OP

  3. DPD

  4. WP

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Correct Option: C

Osmotic pressure of a cell is zero, when

botany plant water relation diffusion pressure deficit other pressure components osmosis in plants

  1. T.P. is maximum

  2. DPD is maximum

  3. T.P. is zero

  4. Not possible

Show answer
Correct Option: D
Explanation:

Osmotic pressure is the pressure responsible for osmosis in the plant. Osmotic pressure depends on the concentration of solute particles in the cell sap. More the concentration of solute particles more the osmotic pressure. The osmotic pressure of cell sap can never be zero, because always there will be some or the other solute particles present in the cell sap. 

The real force responsible for the movement of water from cell to cell is

botany plant water relation diffusion pressure deficit other pressure components osmosis in plants

  1. OP

  2. TP

  3. DPD

  4. WP

Show answer
Correct Option: C
Explanation:

DPD stands for diffusion pressure deficit. The deficit in diffusion pressure depends on the number of solute particles present in the system. In a plant body, water moves from a region of low DPD to a region of high DPD. This is understandable because low DPD means low solute concentration or high concentration of solvent molecules and vice versa for high DPD.