List the characteristics of cork. How are they formed? Mention their role.

• Cork cells are mature and dead
• They are compactly arranged
• They do not have intercellular spaces
• They are thick and have several

Outer protective tissue of the plant undergoes changes with age. Epidermis of the stem is replace by a secondary meristem call phellogen or cork cambium .It is a simple tissue which consists of rectangular cells whose protoplasts are vacuolated. Cork cells contains tanins and chloroplasts.

Cork cambium forms cork on the outer side and secondary cortex on the inner side by giving off new cells on both its sides. The layer of cells which is cut by cork cambium on the outer side ultimately becomes several layered thick cork (bark) of trees.

Cork cells are compactly arranged dead cells and they lack intercellular spaces. Walls of cork cells are thickened with suberin which is fat. Because of Suberin these cells are impermeable to water and gases.

Role of cork

Cork provides protection to plant and it prevents loss of water from plant body. Cork protects the plants from infection and mechanical injury. Cork is light in weight and it cannot catch fire. Because of this property it is used as insulators. Cork is hard in nature hence it is used to make sports goods.