Tag: botany

Questions Related to botany

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'.

DPD is abbreviated form of

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

  1. Daily photosynthetic deficit

  2. Daily phosphorus deficit

  3. Daily pressure deficit

  4. Diffusion pressure deficit

Show answer
Correct Option: D
Explanation:
Diffusion pressure deficit (DPD) is the amount by which two solutions differ in their diffusion pressure. The amount by which the diffusion pressure of water or solvent in a solution is lower than that of pure water or solvent is known as diffusion pressure deficit. 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 D.

The movement of water is along the 

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

  1. Turgor gradient

  2. DPD gradient

  3. Diffusion gradient

  4. Osmotic gradient

Show answer
Correct Option: B
Explanation:

DPD is the diffusion pressure deficit. When a cell is put in a hypertonic solution (solution with the high concentration of solutes than the solute concentration ), a water potential or DPD gradient is created between the cell and the external solution. Hence the water diffuses out of the cell; the process is called exosmosis. Thus water movement is due to DPD gradient not because of turgor gradient, diffusion gradient and osmotic gradient.

A cell with DPD=5 is surrounded by A,B,C and D cell having OP and Tp respectively 5 and 4, 7 and 5, 3 and 2, 0.5 and 0. From which cell it will withdraw water fast? 

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

  1. D

  2. C

  3. B

  4. A

Show answer
Correct Option: D
Explanation:

DPD is the difference between Osmotic pressure and Turgor pressure. 

For cell A the DPD is 1.
For cell B the DPD is 2.
For cell C the DPD is 1
For cell D the DPD is 0.
So, the correct answer is 'D'.

Which of the following is correct about DPD?

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

  1. DPD is the reduction in diffusion pressure of solvent in a system over its pure state

  2. DPD = OP - TP

  3. DPD is zero, entry of water will stop

  4. All of the above

Show answer
Correct Option: D
Explanation:

DPD is diffusion pressure deficit. It is the reduction in the diffusion pressure of solvent in a system over its pure state due to presence of solutes in it and forces opposing diffusion. Pure solvent has the maximum diffusion pressure. DPD is the difference between the osmotic pressure (OP) and turgor pressure (TP). When a cell is turgid, its OP is equal to TP and DPD is zero. When DPD is zero, the entry of water will stop as turgid cell cannot absorb any more water.

Thus, the correct answer is 'All of the above.'

Which of the following is not correct about DPD?

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

  1. It is the loss of diffusion pressure

  2. Maximum value of DPD is equal to OP

  3. DPD of pure water is zero

  4. Low DPD means small gap between the value of OP and TP

Show answer
Correct Option: A
Explanation:

DPD or diffusion pressure deficit is the difference between the diffusion pressure of a solution and a pure solvent when both are subjected to the same atmospheric pressure. Since pure water does not contain any solute particles, therefore it has zero DPD. Movement of water is always from low DPD to high DPD. When increasing turgor pressure becomes equal to decreasing osmotic pressure, the entry of water into the cell would stop.

In a flaccid condition, the value of DPD equals OP.
Hence, the correct answer is 'It is the loss of diffusion pressure'.

Which option is true for a fully turgid cell?

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

  1. OP $=$ DPD

  2. OP $=$ zero

  3. DPD $=$ Zero

  4. TP $=$ Zero

Show answer
Correct Option: C
Explanation:

As the cell becomes fully turgid, the value of turgor pressure becomes equal to that of solute potential $(\Psi _s)$ so that water potential $(\Psi _w)$ or DPD becomes either zero or equal to that of external hypotonic solution.
$\Psi _w=\Psi _s+\Psi _p=0$

Though there is no net movement of water between the cell and its environment, equilibrium is dynamic and not static. Equal exchange of water molecules continues between the cell and its environment.
So, the correct answer is 'DPD = Zero'.

Which of the following equations is correct in respect of osmotic phenomenon ?

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

  1. DPD = OP - TP

  2. DPD = OP + TP

  3. DPD = OP $\times$ TP

  4. DPD = OP $\div$ TP

Show answer
Correct Option: A
Explanation:

DPD = Diffusion pressure deficit

OP = Osmotic pressure
TP = Turgor pressure
Diffusion pressure of a pure solvent is more than the solution and this difference is given by DPD.
TP is developed when water starts entering the cell and the osmotic pressure is the maximum pressure a system can develop in comparison to pure water.
Hence DPD is given when we subtract the TP from the OP.
So the correct answer is 'DPD = OP - TP'.

If DPD represents diffusion pressure deficit, OP is the osmotic pressure and TP is the turgor pressure, then which of the following equations is correct?

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

  1. DPD $=$ OP $=$ TP

  2. DPD $=$ OP $+$ TP

  3. DPD $=$ OP $-$ TP

  4. DPD $=$ OP

Show answer
Correct Option: C
Explanation:

The reduction in the diffusion pressure of water in a solution over its pure state is called diffusion pressure deficit or DPD. Diffusion pressure deficit is also called suction pressure. It value is equal to the osmotic pressure or potential (OP) (positive value taken in bars or atm) of the solution in a cell or system minus the wall pressure (WP) ($=$ turgor pressure, TP) which opposes the entry of water into it provided the external water is pure DPD $=$ OP $-$ WP ($=$TP)

Water is absorbed by a system having higher DPD from another system with lower DPD.
So, the correct answer is 'DPD $=$ OP $-$ TP'.