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प्रश्न
Give Reasons for the following.
On sprinkling common salt on grass growing in a lawn, the grass is killed.
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उत्तर
Sprinkling salt makes soil solution hypertonic hence grass lose water due to exosmosis.
संबंधित प्रश्न
Mention whether the following statement is true or false. Correct the false statement by altering the last word only.
Addition of salt to pickles prevents growth of bacteria because they turn turgid.
Give reason for the following:
Potato cubes, when placed in water, become firm and increase in size.
Define the following:
Osmosis
Explain why:
The leaves of wilted lettuce, if kept in cold water, become crisp.
Mention whether the following statement is true (T) or false (F) and give explanation in support of your answer.
Plasmolysis is reverse of deplasmolysis.
A leaf cell of a water plant was placed in a liquid other than pond water. After sometime, it assumed a shape as shown below:
Redraw in the space provided, the diagram of the cell if it is soon placed in ordinary water for some time.
Give at least three uses of water to green plants
Given below is the figure of an experimental set up to demonstrate root pressure.
(i) Define root pressure.
(ii) What change would you observe in the water level after some time?
(iii) What role is being played by the root pressure in the given experiment?
(iv) Why the oil has been sprinkled on water?
The beaker is divided into two chambers A and B. The big circle represents solute and the small circles solvent.
(i) What can you say about the size of the holes in the membrane, if it is to behave semi- permeably between these two?
(ii) Will the solvent molecules pass through the membrane from left to right, from right to left, in either direction or in both directions?
(iii) In which direction will there be a net movement of solvent molecules?
Fill in the Blank
When there is no movement of water in the cell from the outside medium, the medium is considered to be ______ to cell sap.
