'''Tonisite''' ''efektif osmolarite'' veya ''efektif osmolalite'' nin bir ölçüsüdür. [[Osmolalite]] ve [[osmolarite]] partiküler bir solüsyonun membrandan bağımsız özellikleridir.
* If a cell is placed in a ''hypotonic'' solution (one of lower tonicity than the cell contents), the water concentration is greater outside the cell and so [[osmosis]] produces a net movement of water into the cell. This causes animal cells (without a cell wall) to burst and plant cells (which do have a cell wall) to become ''turgid''.
* If the medium is ''isotonic'', the water concentration is the same on either side of the cell membrane, and there is no net movement of water.