<P> The entire surface of the plant consists of a single layer of cells called epidermis or surface tissue . The entire surface of the plant has this outer layer of epidermis . Hence it is also called surface tissue . Most of the epidermal cells are relatively flat . The outer and lateral walls of the cell are often thicker than the inner walls . The cells forms a continuous sheet without inter cellular spaces . It protects all parts of the plant . </P> <P> The complex tissue consists of more than one type of cells which work together as a unit . Complex tissues help in the transportation of organic material, water and minerals up and down the plants . That is why it is also known as conducting and vascular tissue . The common types of complex permanent tissue are: </P> <Ul> <Li> Xylem or wood </Li> <Li> Phloem or bast . </Li> </Ul> <Li> Xylem or wood </Li>

Describe three functions of the protective tissue in plants