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प्रश्न
Mention whether the following statement is true (T) or false (F) and give explanation in support of your answer.
Plasmolysis is reverse of deplasmolysis.
पर्याय
True
False
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उत्तर
True.
Plasmolysis occurs due to outflow of water from the cell when placed in hypertonic solution due to which the cytoplasm shrinks away from the cell wall. On the other hand, deplasmolysis is the result of the re-entry of water into the plasmolysed cell when placed in hypotonic solution due to which the protoplasm again swells up pressing tight against the cell wall.
संबंधित प्रश्न
Two potato cubes each 1 cm3 in size, were placed separately in two containers (A&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 had somewhat decreased in size. Use the above information to answer the questions that follow:
Account for the firmness and increase in the size of the potato cubes placed in water.
Explain why:
We gargle with saline solution in case of throat infection.
What do you mean by transpiration pull ?
What is the significance of diffusion?
Give Reasons for the following.
Plants growing in fertilized soil are often found to wilt if the soil is not adequately watered. Why?
A plant cell kept in a drop of water was examined under the low power magnification of a microscope, as shown:
(i) What would you do to bring this cell back to its original condition?
(ii) What scientific term is used for such condition?
(iii) Draw the same cell if it is kept in a strong sugar solution.
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?
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?
Fill in the Blank
The pressure which develops in the cortical cells of root which force a part of the water upward ____________.
Define the following term:
Osmotic Pressure
