Water relations of cell: 

                 Water  is life of a living body. It acts as a biological solvent. It takes part in metabolic activities of cell. Its movements in and outside the cell is called osmosis. Osmosis is a process in which solvent moves from higher concentration to the lower concentration through the cell membrane.

Balance of Water and Solutions in the body: 

                 Water is used in most of the metabolic processes in the body of plants. The water moves and comes out of the cells by Osmosis. In osmosis the solvent moves from the region of higher concentration to the region of lower concentration through the plasma membrane.

                  When a plant cell is placed in pure water or hypotonic solution (solution contains more water than cell sap), then endosmosis takes place, due to which water enters the plant cell. As a result of this process the cell becomes turgid. By the continue movement of water inside the cell, it does not burst, because cell wall causes internal hydrostatic pressure or pressure potential, which does not allow further movement of water inside the cell.

                 When plant cell is placed in a hypertonic solution (more concentrated solution than cell sap), exosmosis occurs, the water moves from inside to outside, so the cytoplasm of cell shrinks from the cell wall, it is called plasmolysis.