• Turgidity: This occurs when a plant cell is placed in a solution which is weaker than the solution in the cell sap vacuole (In a dilute solution) water enters the cell by osmosis making the cell to swell. The amount of water entering a fully turgid cell is the same like the amount of water leaving it.
• Turgor Pressure: This is the outward pressure exerted by the vacuole on the cell wall as a result of the vacuole being filled with water.
• Back or Wall Pressure: This is the opposing inward pressure exerted by the cell wall on the expanding vacuole. When turgor pressure is equal to wall pressure, the cell is said to be turgid.
• Plasmolysis: If a plant cell is placed in a stronger solution like sugar or salt solution, water leaves the cell to the surrounding solution by osmosis. The cytoplasm shrinks away from the cell wall and the volume of the vacuole decreases. The cells in this state are said to be plasmolysed.

Wilting:  This is when a plant seedling is losing water in hot conditions by transpiration more than it can absorb from the cell.