
Rupa B. answered 12/10/12
Well qualified and experienced biology and chemistry tutor
Plant cells are actively involved in water transportation, and thus plant cell wall ensures that the cell does not burst due to over expansion as water flows in (internal turgor pressure). It helps to maintain the shape and osmolarity of thecells and acts as defense against pressure due to inflow of water.
Besides this cell walls also provides structural and mechanical support, protection against pathogens and dehydration.