What are tissues ? What are their main groups?



Tissue : A group of similar or dissimilar cells having a common origin and co-operating with one another to perform a similar or a set of similar functions is called a tissue. Plant tissues have been classified into two fundamental types : (1) Meristematic tissue : These are the tissues which are made up of group of immature and similar cells and are in continuous state of division and forming new cells. (2) Permanent tissue : These are composed of mature cells which have definite shape, size and functions and have lost the power of divisions.