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प्रश्न
Explain why:
The leaves of wilted lettuce, if kept in cold water, become crisp.
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उत्तर
The leaves of the wilted lettuce become crisp when kept in cold water because they take up water due to endosmosis in hypotonic solution.
संबंधित प्रश्न
A candidate in order to study the process of osmosis has taken 3 potato cubes and put them in 3 different beakers containing 3 different solutions. After 24 hours, in the first beaker the potato cube increased in size, in the second beaker the potato cube decreased in size and in the third beaker there was no change in the size of the potato cube. The following diagram shows the result of the same experiment:
(i) Give the technical terms of the solutions used in beakers, 1, 2 and 3.
(ii) In beaker 3, the size of the potato cube remains the same. Explain the reason in brief.
(iii) Write the specific feature of the cell sap of root hairs which helps in absorption of water.
(iv) What is osmosis?
(v) How does a cell wall and a cell membrane differ in their permeability?
Complete the following statements:
Hypotonic solution is one in which the solution kept outside the cell has lower solute concentration than ……………… the cell.
When placed in a more concentrated solution, the cell contents will ______.
Differentiate between the following:
Plasmolysis and deplasmolysis
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:
Comment on the nature (tonicity) of the liquid surrounding the cell.
In an experiment, two sets of apparatus were set up as shown below:
In A there is a concentrated sugar solution inside the thistle funnel and red ink in the water outside the funnel. In B there is a concentrated glucose solution with red ink inside the thistle funnel and water outside the thistle funnel.
In both A and B the level of liquid inside the funnels rises up the tubes. In A the sugar solution turns red and in B, the water turns red.
Study the given observations and answer these questions:
- Name the process by which red ink moves in A and B.
- Which type of pressure forces the water molecules to move towards thistle funnels and cause a rise in the water level?
- Where does this process occur in plants and animals?
- What material could be used as a semi-permeable membrane?
Give Technical Term for the following.
The pressure which is responsible for the movement of water molecules across the cortical cells of the root.
Define the following term:
Osmotic Pressure
