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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?
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उत्तर
(i)
Solution 1 – Hypotonic solution
Solution 2 – Hypertonic solution
Solution 3 – Isotonic solution
(ii) In beaker three, the solution present is an isotonic solution, i.e. the relative concentration of water molecules and solutes is same in the solution as well as inside the cell. There is no movement of water molecules across the cell membrane. Hence, the size of the potato cubes remains same.
(iii) The cell sap of root hairs has higher concentration of solute than the surrounding water.
(iv) Osmosis is the diffusion of water molecules across the semi-permeable membrane from the region of dilute solution (i.e. a lower solute concentration) to the region of concentrated solution (i.e. a higher solute concentration).
(v) The cell wall is freely permeable to all the substances, while the cell membrane is selectively permeable and allows only certain substances to enter or exit the cell.
संबंधित प्रश्न
A plant cell placed in a certain solution got plasmolysed. What was the kind of solution?
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.
Give at least three uses of water to green plants
Differentiate between the following
Endosmosis and Exosmosis
The apparatus arranged here signifies an important process.
(i) Name the process.
(ii) Where does this process occur in plants?
(iii) What solution is placed inside the dialysis tubing?
(iv) What happens to the level of the solution in the capillary tube?
(v) Define the process mentioned in Q. (i) above.
The beaker is divided into two chambers A and B. The big circle represents solute and the small circles solvent.
(i) What can you say about the size of the holes in the membrane, if it is to behave semi- permeably between these two?
(ii) Will the solvent molecules pass through the membrane from left to right, from right to left, in either direction or in both directions?
(iii) In which direction will there be a net movement of solvent molecules?
Give Technical Term for the following.
The condition in which the water from a cell is completely removed due to exosmosis and no more shrinkage is possible.
Name the following:
Name the process by which water enters the root hair cell.
Name the following:
Condition of cell in which the cell content are shrunken.
Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:
During exosmosis, water moves from inside the cell to the outside of the cell.
