Question

The external solution having same concentration as that of cell sap is known as

• A. Hypertonic solution
• B. Isotonic solution
• C. Hypotonic solution
• D. Ultratonic solution

Answer 1

The correct option is B Isotonic solution

When cells are in isotonic solution, movement of water out of the cell is exactly balanced by movement of water into the cell.

If concentrations of dissolved solutes are less outside the cell than inside, the concentration of water outside is correspondingly greater. When a cell is exposed to such hypotonic conditions, there is net water movement into the cell. Cells without walls will swell and may burst (lyse)

In hypertonic solutions, concentrations of dissolved solutes are greater outside the cell and so the concentration of water outside is correspondingly lower. As a result, water inside the cell will flow outwards to attain equilibrium, causing the cell to shrink. As cells lose water, they lose the ability to function or divide.
There is nothing like ultratonic solution.

Thus, the correct answer is option (B).