Tag: plant water relation
Questions Related to plant water relation
Which of the following statements is correct?
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Bacteria do not survive in salted pickles because they get plasmolysed in hypertonic medium
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Osmotic potential is numerically equal to the osmotic pressure but is negative in sign
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Kneading of wheat flour is accompanied by release of heat which is due to imbibition
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All of these
Following are the correct statements:
Choose the correct answers from the alternatives given :
In which one of the following processes the phenomenon of osmosis is not involved
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Water entering a mesophyll cell from xylem vessel element
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Water passing from root hair to adjacent cells
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Water from soil entering a root hair
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Water passing up a xylem vessel element to xylem vessel above it
Osmosis is the movement of solvent from its higher concentration to its lower concentration across a semipermeable membrane. Movement of water through xylem element to xylem vessels above it occurs due to the cohesive force between the water molecules, suction pressure and transpiration pull.
DPD is equal to :
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OP $ \times $ TP (WP)
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OP $ + $ TP (WP)
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OP $ - $ TP (WP)
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TP (WP) $ - $ OP
- 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 is known as diffusion pressure deficit. It allows for easy absorption of water due to the diffusion pressure gradient. Water moves from lower DPD to higher DPD.
- It is equal to the difference between osmotic pressure and turgor pressure.
- DPD of a cell is influenced by both osmotic pressure and wall pressure (turgor pressure) which opposes the endosmotic entry of water, i.e. DPD = OP - wall pressure.
Water passes into cell or one cell to another due to
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O.P.
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D.P.D.
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W.P.
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Diffusion
The actual pressure with which water enters into the cell is called as
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D.P.D.
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O.P.
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W.P.
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Diffusion
Actual flow of water is decided by the deficit in diffusion pressure. More the dissolved solute particles greater will be the deficit in diffusion pressure and lesser the number of solute particles lesser will be deficit in diffusion pressure. One more component is the wall pressure which is equal and opposite to the turgor pressure. Mathematically expressed DPD is equal to OP - TP. Water moves from an area of lower DPD to an area of higher DPD.
If cell A with DPD $5$ atm is surrounded by many cells with DPD $4$ atm then.
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The net movement of water will be from cell A to the surrounding cells
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Net movement of water will be into cell A from the surrounding cells
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Water will not move at all
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Water movement will depend on other unknown factors
The actual pressure with which water enters into cell is called
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DPD
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OP
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WP
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Diffusion
The actual pressure with which water enters into a cell is 'Diffusion Pressure Deficit' or DPD. It can be calculated as the difference in the osmotic pressure and turgor pressure. Osmotic pressure causes movement of water into the cell and develops because of the solutes dissolved in the solution of cell sap. On the other hand the turgor pressure is an opposing force, which works in the direction opposite to the movement of water and prevents entry of water into the cell. Turgor pressure develops because of the entry of water into the cell.
The osmotic parameter determining flow of water from one cell to another is
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Osmotic pressure
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Turgor pressure
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Diffusion pressure deficit
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Hydrostatic pressure
Diffusion pressure deficit (DPD) is a negative measurement to understand the flow of water from one cell to another. It is important to note that we are considering deficit in diffusion pressure and not diffusion pressure. As a rule, water always flows from lower DPD to higher DPD. This is because lesser the dissolved salts, lesser will be the deficit (so low DPD) and more the dissolved salts more will the deficit (so high DPD). As you can guess water will flow from a region of lower dissolved salts (i.e., low DPD) towards a region of more dissolved salts (i.e., higher DPD).
Which of the following is not correct about $DPD$?
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Its the loss of diffusion pressure
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Maximum valu of $DPD$ is equal to $OP$
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$DPD$ of pure $H _{2}O$ is zero
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Increase in $TP$ of a cell decreases $DPD$
The term diffusion pressure deficit (DPD) is the reduction in the diffusion pressure of water in solution or cell over its pure state due to presence of solutes in it and forces opposing diffusion. Diffusion pressure of water is maximum and its theoretical value is 1236 atm. DPD of a solution is equal to its osmotic pressure i.e. DPD = OP(of solution). DPD of a cell is influence by both osmotic pressure and wall pressure (turgor pressure) which opposes the endosmotic entry of water, i.e. DPD = OP - Wall pressure. DPD is directly proportional to the concentration of the solution. DPD decreases with dilution of solution. The actual pressure with which cell absorbs water is called "suction pressure".
Which of the following is incorrectly match :-
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For fully turgid cell $ \Rightarrow $ DPD $ = 0 $
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DPD of solution is vessel $ \Rightarrow $ $ OP - TP = 0 $
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For full turgid cell $ \Rightarrow OP = TP $
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DPD for a flaccid cell $ \Rightarrow DPD = OP $
It is reduction in the diffusion pressure of water in solution or cell over its pure state due to presence of solutes in it and forces opposing diffusion. Diffusion pressure of water is maximum and its theoretical value is 1236 atm. DPD of a solution is equal to its osmotic pressure i.e. DPD = OP(of solution) and in this case the DPD is not zero. For a turgid cell OP=TP and DPD=0. DPD for a flaccid cell is maximum and is equal to OP.