Tag: plant water relation

Questions Related to plant water relation

The term "DPD" was coined by

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

  1. Renner

  2. Kramer

  3. B. S. Mayer

  4. Stephen Hales

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Correct Option: C
Explanation:

The amount by which the diffusion pressure of a solution is lower than that of the pure solvent is called as 'diffusion pressure deficit' (DPD). The term diffusion pressure deficit (DPD) was coined by B.S Meyer in 1938. Originally DPD was described as suction pressure by Renner (1915).

If the given solution is of 25% concentration; then what cannot be presented for this

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

  1. OP

  2. DPD

  3. Solute potential

  4. TP

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Correct Option: D
Explanation:

When a cell is immersed in water, then water enter into the cell because the osmotic pressure of the cell sap is higher. The cell content develops a pressure against the cell wall, which is called turgor pressure. If the given solution is of 25% concentration; then it can not represent TP(turgor pressure) because pressure cannot be expressed in terms of concentration.

So, the correct answer is 'TP'.

In a fully turgid cell, the values of DPD, OP and TP will show the tendency

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

  1. DPD$=$10atm, OP$=$15atm, TP$=$5atm

  2. DPD$=$5atm, OP$=$12atm, TP$=$7atm

  3. DPD$=$2atm, OP$=$7atm, TP$=$5atm

  4. DPD$=$0atm, OP$=$15atm, TP$=$15atm

Show answer
Correct Option: D
Explanation:

In a fully turgid cell there will be no net movement of water. Neither water will move inside nor move outside. This is because DPD will be zero. DPD can be zero, when the osmotic pressure, which causes movement of water inside the cell equals to turgor pressure, which opposes the entry of water inside the cell.

When the mesophyll cells lose water, their DPD will

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

  1. Increase

  2. Decrease

  3. Remain constant

  4. None of the above is applicable

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Correct Option: A
Explanation:

When the mesophyll cells lose water the concentration of solutes will increase. Consequently, the OP will increase concomitantly, there will be a drop in turgor and TP will decrease. These changes will increase the DPD. Water moves from lower DPD to higher DPD, thus, water will gain entry into the cells, whose DPD has increased.

Which is Zero in Turgid cell ________.

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

  1. OP

  2. TP

  3. DPD

  4. DP

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Correct Option: C

A and B cells are contiguous. Cell $1$ has OP$=10$ atm. TP=$7$ atm and DPD$=3$ atm. Cell $2$ has OP $=8$atm, TP$=3$ atm and DPD$=5$ atm. The result would be __________________.

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

  1. No movement of water

  2. Equilibrium between the two

  3. Movement of water from $1$ to $2$

  4. Movement of water from $2$ to $1$

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Correct Option: C

A plasmolysed cell placed in hypotonic solution then the water enter in it, the force which is responsible for it is __________.

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

  1. DPD

  2. OP

  3. WP

  4. None of these

Show answer
Correct Option: B
Explanation:

Answer is option B i.e. "OP"
Hypotonic solution is one in which the solution kept outside the cell has lower solute concentration than the fluid inside the cell. The process being investigated is osmosis. Osmosis is the diffusion of water molecules across a semi-permeable membrane from a more dilute solution (with a lower solute concentration) to a less dilute solution (with a higher solute concentration). Therefore cell absorbs or sucks water with a force equal to O.P

In a plant cell the diffusion pressure deficit is zero when it is 

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

  1. Plasmolysed.

  2. Turgid.

  3. Flaccid.

  4. Incipient.

Show answer
Correct Option: B
Explanation:

Diffusion Pressure Deficit = osmotic pressure - wall pressure. Wall pressure is the same as Turgor pressure. When a cell is placed in a hypotonic solution water enters the cell. Hence its osmotic pressure decreases and the turgor pressure increases. In a fully turgid cell the turgor pressure becomes equal to the osmotic pressure. Hence the Diffusion Pressure Deficit becomes zero in a turgid cell. Thus the correct answer is option B.

The force which determines the flow of water from one cell to another is

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

  1. T.P.

  2. D.P.D

  3. O.P.

  4. W.P.

Show answer
Correct Option: B
Explanation:
The force which determines the flow of water from one cell to another is diffusion pressure deficit. Diffusion pressure deficit (DPD) is the amount by which two solutions differ in their diffusion pressure. It is defined as the amount by which the diffusion pressure of water or solvent in a solution is lower than that of pure water or solvent. It allows easy absorption of water due to diffusion pressure gradient. Water moves from lower DPD to higher DPD.
So, the correct answer is option B.

Root hair absorb water from soil due to

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

  1. Osmotic pressure

  2. Turgor pressure

  3. Suction pressure

  4. Root pressure

Show answer
Correct Option: C
Explanation:

Suction pressure is the decrease in the diffusion pressure of solution over its pure state due to the presence of solute particles in it. The concentration of solute is higher in root hair cells as compared to soil water. So suction pressure builds up and water is drawn towards root hair cells. These water molecules are transported to different parts of the plant. So, the correct answer is 'Suction pressure'.