When the plants and bacteria reach water, they get into a hypotonic solution means, the concentration of solutes is greater inside the cell than outside of it. When the plant and bacteria are placed in water, they take up water by osmosis and starts to swell, but the cell wall prevents it from bursting. The plant cell become turgid. Turgidity means the cells are swollen and hard. The increase in pressure makes the cell rigid. This is why they do not expand and burst.
