Formation of Cavities in cell wall
- In Young Plants cells are pressed together. There is no space in between them. Walls separate with the successive growth of cells and form intercellular spaces. They are filled with minerals, water or air thereafter. These are called cavities.
- They are the following three types
(i) Schizogenous Cavities :
- Large air spaces are seen when cells separate from each other. These are called schizogenous cavities.
- They help in diffusion of liquid substances and gases.
- Example- resin canal in Pinus.
(ii) Lysigenous cavities :
- They are formed by disintegration of cells.
- Example oil gland of Citrus (lemon).
(ii) Schizolysigenous cavities :
- These schizolysigenous cavities are formed by disintegration of intra cellular spaces and cells.
- For example cavities present in protoxylem of stem of maize.
Function of cell wall
(i) to provide strength to the cell.
i) it protects the cell and provides strength.
(iii) It also protects the cytoplasm from outer injury.
ii) Cell wall is permeable to solvent and solute so that substances can move from one cell to another cell through diffusion.
(iv) The nature of cell walls is colloidal hence it can imbibe water easily.