Question

The process of plasmolysis in a plant cell may be defined as
A. Bursting of the plasma membrane in a hypotonic medium.
B. Shrinkage of cytoplasm in the hypertonic medium.
C. Breakage of the plasma membrane in a hypertonic medium.
D. Shrinkage of cytoplasm in the hypotonic medium.

Answer 1

Hint: In a hypertonic solution, plasmolysis is the phase in which cells remove water. If the cell is in a hypotonic solution that results in a lower external osmotic pressure and a net flow of water into the cell, the reverse process, deplasmolysis or cytolysis, can occur.

Complete answer: Hypertonic solution- There is a greater concentration of solutes for a hypertonic solution than for another solution. The concentration of solutes compared to that of another solution on the opposite side of a cell membrane; since it contains a higher concentration of solutes than the cytosol within the cell, a solution outside of a cell is considered hypertonic. When a cell is immersed in a hypertonic solution, osmotic pressure appears to cause water to escape out of the cell.
Hypotonic solution- A solution that is hypotonic has a lower concentration of solutes than another solution. This is because it has a lower concentration of solutes compared to the cytosol, a solution outside of a cell is considered hypotonic. Water diffuses into the cell due to osmotic pressure, and the cell sometimes looks turgid, or bloated. If the gradient is high enough for cells without a cell wall, such as animal cells, the absorption of excess water may generate sufficient pressure to cause cytolysis or cell rupture.
Isotonic solution- When its efficient osmotic concentration is the same as that of another solution, a solution is isotonic. When the concentration of solutes outside the cell equals the concentration of solutes within the cell, the solutions on either side of a cell membrane are isotonic. In this case, since there is no concentration gradient to induce the diffusion of significant quantities of water through the cell membrane, the cell neither swells nor shrinks.
Hence, the correct answer is option B, i.e., Shrinkage of cytoplasm in hypertonic medium.

Note: Plasmolysis in a plant cell is known as the cytoplasm shrinkage process as a result of water loss from the cell. This happens when plant cells are placed in a solution with a higher concentration of solutes than that of the cell. In this, the hypertonic solution is kept in the plant cell. Cells are lysed when cells are put in a hypotonic solution.