Tag: plant water relation

Questions Related to plant water relation

A and B are contiguous cells. A has osmotic pressure (OP) = 10 atm. Turgor pressure (TP) = 7 atm and Diffusion pressure deficit (DPD) = 3atm. B has OP = 8 atm, TP = 3 atm, DPD = 5 atm. The direction taken by the water 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 A to B

  4. Movement of water from B to A

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Correct Option: C
Explanation:

Movement of water from A to B since water flows in the direction from low DPD to high DPD.  'A' cell has lower DPD than 'B' so the movement of water from A cell to B cell will be the correct answer.

In a plant cell DPD 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

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Correct Option: B
Explanation:

A cell is fully turgid means it is full of water i.e, it cannot absorb any more water. In a fully turgid cell DPD (Diffusion Pressure Deficit) is zero and the net movement of water into the cell stops satisfying the equation  DPD =  OP +  TP. Therefore, for the fully turgid cells has DPD is zero satisfying osmotic pressure (OP) and turgor pressure (TP) must be equal, when a cell absorbs more and more water turgor pressure increases thereby it will be positive value and osmotic pressure decreases hence it is negative value.

So, the correct answer is option B.

Arrange root hair cell, inner cortical cell and mesophyll cell in ascending order of DPD.

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

  1. Mesophyll cell, root hair cell and cortical cell

  2. Cortical cell, mesophyll cell, and root hair cell

  3. Root hair cell, cortical cell and mesophyll cell

  4. Root hair cell, mesophyll cell and cortical cell

Show answer
Correct Option: C
Explanation:

DPD means deficit pressure diffusion. Roots absorb water through root hairs. For the absorption of water, there should be a concentration gradient between root hair and soil.

Root hair cells are creating concentration gradient and these are absorbing so water amount is more in this region so DPD is less. Cortical cells are present in the stem region so the amount of water is somewhat less in this region and DPD is more.
Mesophyll cells are present in leaves so here the amount of water is less and DPD is more and highest in this region.
So, the correct answer is 'Root hair cell, cortical cell and mesophyll cell'.

If two solution have the same osmolarity, they are said to be

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Hypertonic

  2. Hypotonic

  3. Isotonic

  4. None of the above

Show answer
Correct Option: C
Explanation:

Isotonic means two solutions having the same osmolarity. It allows the free movement of water across the membrane without changing the solute concentration. Hypotonic surrounding solution means a solution with less osmolarity. This means that concentration of solutes is less in the surrounding medium, than the concentration of solutes in cell sap and hypertonic surrounding solution means the concentration of solutes is more than the concentration of solutes in the cell sap.

The space between the plasma membrane and the cell wall of a plasmolyzed cell surrounded by a hypertonic solution is occupied by the

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Hypotonic solution.

  2. Isotonic solution.

  3. Hypertonic solution.

  4. Water.

Show answer
Correct Option: C
Explanation:

A plant cell wall is fully permeable and it cannot regulate the entry or exit of a solution. When a plant cell is placed in a hypertonic solution it will lose water by exosmosis. This process is called plasmolysis. The protoplasm will shrink and will move inwards and away from the cell wall. As a result, the hypertonic solution will occupy the space between the plasma membrane and the cell wall. Thus the correct answer is option C.

All the following involves osmosis except.

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Water from soil entering a root hair

  2. Water passing from root hair to adjacent cells

  3. Water passing up a xylem vessel element to xylem vessel element above it

  4. Water entering a mesophyll cell from xylem vessel element

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Correct Option: A

At the time of opening of stomata, pH of guard cells in comparison to pH of subsidiary cells, is?

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Higher

  2. Lower

  3. Equal

  4. Uncertain

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Correct Option: A

Two cells A and B are contiguous. Cell A has osmotic pressure $10$atm, turgor pressure $1$ atm and diffusion pressure deficit $3$ atm. Cell B has osmotic pressure $8$ atm, turgor pressure $3$ atm and diffusion pressure deficit $5$ atm. The result will be?

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Movement of water from cell B to A

  2. No movement of water

  3. Equilibrium between the two

  4. Movement of water from cell A to B

Show answer
Correct Option: A

When a plant cell is placed in a solution which is hypotonic to the cell sap, which of the following conditions will not apply

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. The water potential of the cell sap will rise

  2. The suction pressure of the cell sap will fail

  3. The cell will become turgid

  4. The wall pressure of the cell will fail

Show answer
Correct Option: D
Explanation:

If a cell is placed in hypotonic solution, water start moving into the cell by the process of endosmosis and cell become turgid.

Ephemerals are drought ___________.

biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

  1. Loving

  2. Enduring

  3. Escaping

  4. Resistant

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Correct Option: C