- The concentration of water molecules in surrounding medium is higher than water molecules concentration in the cell.
Explanation:
Osmosis is a spontaneous process where movement of solvent molecules occurs into a region of higher solute concentration from lower solute concentration through a partially permeable membrane, so as to tend to equalise the solute concentration on the two sides.
When movement of the solvent takes place from outside to inside the all (inward movement) the process is endosmosis. It occurs in hypotonic solution and causes the swelling of cell.

Osmosis is a spontaneous process where movement of solvent molecules occurs into a region of higher solute concentration from lower solute concentration through a partially permeable membrane, so as to tend to equalise the solute concentration on the two sides.
When movement of the solvent takes place from outside to inside the all (inward movement) the process is endosmosis. It occurs in hypotonic solution and causes the swelling of cell.

When the concentration of water both in the surrounding medium and in the cell is same, the solution in the the surrounding medium is said to be isotonic and no movement of water molecule takes place.
