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प्रश्न
Explain the term:
Plasmolysis
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उत्तर
- When a living cell is placed in a hypertonic solution, exo-osmosis occurs. This is called plasmolysis.
- During plasmolysis, the protoplast of the cell shrinks and recedes from the cell wall, causing the cell to become flaccid. Such a cell is called a plasmolysed cell.
- In a plasmolyzed cell, a gap is developed between the cell wall and the protoplast. This gap is filled by the outer solution.
संबंधित प्रश्न
Give the appropriate biological or technical term for the following.
Movement of molecules of a substance from their higher concentration to lower concentration when they are in direct contact.
Movement of molecules of a substance from the region of their higher concentration to the region of their lower concentration without the involvement a separating membrane, is called
Complete the following statements:
Hypotonic solution is one in which the solution kept outside the cell has lower solute concentration than ……………… the cell.
The following diagram represents a plant cell after being placed in a strong sugar solution.
Guidelines 1 to 5 indicate the following
(1)Cell wall, (2) Strong sugar solution, (3) Protoplasm (4) Large vacuole, (5) Nucleus
(1)What is the state of the cell shown in the cell shown in the diagram?
(2)Name the structure which acts as a selectively permeable membrane.
(3)If the cell had been placed in distilled water instead of strong sugar solution, which feature would not have been seen?
(4)Name any one feature of this plant cell which is not present in an animal cell.
Define the following:
Osmosis
Distinguish between the following:
Turgor pressure and osmotic pressure
Distinguish between the following:
Plasmolysis and deplasmolysis
Name the following:
The inward movement of solvent molecules through the plasma membrane of the cell.
Explain why:
The leaves of wilted lettuce, if kept in cold water, become crisp.
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.
A leaf cell of a water plant was placed in a liquid other than pond water. After sometime, it assumed a shape as shown below:
Comment on the nature (tonicity) of the liquid surrounding the cell.
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.
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.
A solution whose concentration is equal to the cell sap.
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.
Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:
Osmosis is defined as the movement of water from a concentrated sugar solution to a dilute sugar solution.
