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Question
Give Reasons for the following.
Salt and sugar are used in preserving food.
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Solution
Salt and sugar increase the concentration of food, destroying bacteria by plasmolysis.
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Cell turgidity is caused by _______________
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If a marine plant is transferred to fresh water, it bursts due to ___________
Two potato cubes each 1 cm3 in size, were placed separately in two containers (A and B), the container A having water and the other (B) containing concentrated sugar solution. After 24 hours when the cubes were examined, those placed in water were found to be firm and had increased slightly in size and those placed in concentrated sugar solution were found to be soft and somewhat decreased in size. Use the above information to answer the questions that follow:
Account for the softness and decrease in size of the potato cubes which were placed in sugar solution.
What do you mean by transpiration pull ?
Give Reasons for the following.
It is necessary to maintain a normal osmotic concentration of the blood.
Give Reasons for the following.
On sprinkling common salt on grass growing in a lawn, the grass is killed.
In the figure below ‘A’ shows a cell in the normal state and ‘B’ shows the same cell after leaving it in a certain solution for a few minutes.
(i) Describe the change which has occurred in the cell as seen in B.
(ii) Give the technical term for the condition of the cell as reached in B and as it was in A.
(iii) Define the process which led to this condition.
(iv) What was the solution-isotonic, hypotonic or hypertonic, in which the cell was kept?
(v) How can the cell in B, be brought back to its original condition?
(vi) Name the parts numbered 1 to 3.
The diagram below represents an experimental set up to demonstrate a vital process. Study the same and then answer the questions that follow:
(i) Name the process.
(ii) Define the above named process.
(iii) What would you observe in the experimental setup after an hour or so?
(iv) What control experiment can be set up for the above experiment?
(v) Keeping in mind the root hair cell and its surrounding name the part that corresponds to (1) Concentrated sugar solution, (2) Parchment paper, (3) Water in the beaker.
(vi) Name any other substance that can be used instead of parchment paper in the above experiment.
(vii) Mention two advantages of this process to the plant.
Fill in the Blank
The pressure which develops in the cortical cells of root which force a part of the water upward ____________.
Explain the term:
Diffusion
