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Question
Explain why:
Bacteria and fungi do not grow in pickles, jams, jellies and squashes.
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Solution
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.
RELATED QUESTIONS
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.
When placed in a more concentrated solution, the cell contents will ______.
(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.
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 Reasons for the following.
Salt and sugar are used in preserving food.
Give Reasons for the following.
Plants growing in fertilized soil are often found to wilt if the soil is not adequately watered. Why?
Fill in the Blanks
Diffusion is the movement of molecules from a region of their ________ concentration to the region of their ________ concentration.
During a practical exam, a plant cell in a particular solution was placed under a compound microscope. Students were told to observe the cell and name the tonicity of the solution and mention the process that occurred in the cell.
