Chapter Tissues class 9th ( introduction and temporary plant tissue plant tissue)

Tissue-----Group of cells which are structurally similar and perform same function like muscle tissue of xylem etc.are called tissue.

Significance of tissues:-
1. It enables division of labour so that  in multicellular organisms all work is divided by all the cells .
2. It enhances the efficiency of work. 
3. it helps in doing more complex functions.

Types of Tissue----
1 Plant tissue 
2 Animal tissue

Plant tissue -Temporary (meristmatic )& Permanent 
The tissues which change into other types of tissues are called temporary while the others which remain same are called permanent.

Meristmatic tissue -The cells of meristmatic tissue are fast growing rich in cytoplasm well defined nucleus and mostly lack vacoule. these cells divide very fast and keep changing into other type of tissue.
Types of meristmatic cells 

1Apical meristem -----These are present in the root and shoot tips They help in increasing the height and depth of the plant.
 2Lateral meristem----These cells are present in the periphery and are responsible for increasing the diameter (girth) of the plant .This is also called cambium.
3Intercalary meristem -----These cells are present at the base of leaves or internodes (on both sides of nodes).They help in developing branches.
 


(Draw this diagram in the notebook with labelling)