Figure 6.10 Osmosis Can Modify the Shapes of Cells In a solution that is isotonic with the cytoplasm (A), a plant or animal cell maintains a consistent, characteristic shape because there is no net movement of water into or out of the cell. In these models, it is assumed that the solutes do not move across the membrane. In a solution that is hypotonic to the cytoplasm (B), water enters the cell. An environment that is hypertonic to the cytoplasm (C) results in water leaving the cell.