The effects of osmosis on animal and plant cells

Animal cells

Red blood cells placed in a solution with the same water concentration as their cytoplasm (0.85 per cent salt solution) will not experience an overall change in volume. No osmosis occurs.

Blood cells surrounded by dilute solution are hypotonic. The cells swell then burst.

Red blood cells placed in a solution with a higher water concentration compared to their contents (eg pure water) will gain water by osmosis, swell up and burst.

Water will diffuse from a higher water concentration outside the cell to a lower water concentration inside the cell.

Blood cells surrounded by concentrated solution are hypertonic. The cells shrivel.

Red blood cells placed in a solution with a lower water concentration compared to their contents (eg 1.7 per cent salt solution) will lose water by osmosis and shrink.

Water will diffuse from a higher water concentration inside the cell to a lower water concentration outside the cell.