Tag: plant water relation

Quizzes (6) Questions (146)

Questions Related to plant water relation

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

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

  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
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

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

In a plant cell DPD is zero when it is 

  1. Plasmolysed

  2. Turgid

  3. Flaccid

  4. Incipient
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

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

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

  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
Reveal answer Fill a bubble to check yourself
C Correct answer
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'.

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

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

  1. Hypertonic

  2. Hypotonic

  3. Isotonic

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

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

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

  1. Hypotonic solution.

  2. Isotonic solution.

  3. Hypertonic solution.

  4. Water.
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

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

All the following involves osmosis except.

  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
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Osmosis is the movement of water across a semi-permeable membrane. Water moving up a xylem vessel is primarily driven by transpiration pull and cohesion-tension, not osmosis.

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

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?

  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
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice biology movement in and out of the cell transport of molecules osmosis and plasmolysis plant water relation

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

  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
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

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