The animal cell will shrink due to loss of water to the external solution
Explanation:
An isotonic solution is that solution which has equal concentration with its external environment. Hence, no net movement of water occurs in an isotonic solution since there is no concentration gradient. Therefore, if an animal cell is placed in an isotonic solution at first, no net movement of water occurs because the intracellular and extracellular concentrations are at equilibrium.
However, if more solutes are added to the solution, it makes the solution HYPERTONIC to the cell i.e greater in concentration. This creates an osmotic gradient and causes water to move out of the animal cell into the solution in accordance to osmotic principles (movement of water from a low concentration of solute to high concentration of solute). This causes the animal cell to likely SHRINK.
