Osmosis

• Osmosis is the movement of water molecules from an area of high concentration to low concentration through a partially permeable membrane.
• Water moves into plant cells by osmosis until they are turgid (taut).
• If there is too much water in the cell it will burst due to the pressure exerted by the water.
• Plant cells have a rigid cell wall which prevents them from bursting when they become turgid.
• When plants lose water, their leaves wilt as the cells shrink because they no longer contain enough water to be turgid.