(a) With the help of well-labelled diagrams, describe the processof plasmolysis in plants, giving appropriate examples.
(b) Explain what will happen to a plant cell if it is kept in asolution having higher water potential.
(a) With the help of well-labelled diagrams, describe the processof plasmolysis in plants, giving appropriate examples.
(b) Explain what will happen to a plant cell if it is kept in asolution having higher water potential.
(a) Plasmolysis can be defined as the shrinkage of thecytoplasm of a plant cell, away from its cell wall and toward thecentre. It occurs because of the movement of water from theintracellular space to the outer-cellular space. This happens whenthe plant cell is placed in a hypertonic solution (i.e., a solutionhaving more solute concentration than the cell cytoplasm). Thiscauses the water to move out of the cell and toward the solution. Thecytoplasm of the cell shrinks and the cell is said to be plasmolysed.This process can be observed in an onion peel kept in a highlyconcentrated salt solution.
(b) When a plant cell is placed in a hypertonic solution ora solution having higher water potential, the water diffuses into thecell (i.e., movement is observed from higher to lower water pressureregion). The entry of water in the plant cell exerts pressure on therigid cell wall. This is called turgor pressure. As a result of itsrigid cell wall, the plant cell does not burst.
(a) Plasmolysis can be defined as the shrinkage of thecytoplasm of a plant cell, away from its cell wall and toward thecentre. It occurs because of the movement of water from theintracellular space to the outer-cellular space. This happens whenthe plant cell is placed in a hypertonic solution (i.e., a solutionhaving more solute concentration than the cell cytoplasm). Thiscauses the water to move out of the cell and toward the solution. Thecytoplasm of the cell shrinks and the cell is said to be plasmolysed.This process can be observed in an onion peel kept in a highlyconcentrated salt solution.
(b) When a plant cell is placed in a hypertonic solution ora solution having higher water potential, the water diffuses into thecell (i.e., movement is observed from higher to lower water pressureregion). The entry of water in the plant cell exerts pressure on therigid cell wall. This is called turgor pressure. As a result of itsrigid cell wall, the plant cell does not burst.
