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प्रश्न
Explain why:
Bacteria and fungi do not grow in pickles, jams, jellies and squashes.
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उत्तर
Jam, jellies and pickles are kept in hypertonic solution of sugar or salt in which plasmolysis of bacteria and fungi takes place. This kills the bacteria and fungi and hence, pickles, jam and jellies are preserved properly.
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?
Differentiate between the following pairs on the basis of what is indicated in the brackets.
Hypotonic solution and Hypertonic solution [condition of a plant cell when placed in them]
Complete the following statements:
Hypotonic solution is one in which the solution kept outside the cell has lower solute concentration than ……………… the cell.
(a) Mention whether the following statement is true (True) or false (False)
(b) Correct the false statement by altering the last word only.
A plant cell placed in hypotonic solution gets Plasmolysed.
Define the following:
Diffusion
Define the term:
Plasmolysis
Give a diagrammatic representation of plasmolysis in a cell.
Name the following:
The pressure through which water can rise upto some feet.
Fill in the Blanks
Osmosis in the diffusion of _______ molecules from the region of higher _____ potential to that of lower potential across a S.P.M.
