Question

difference between parenchyma ,collenchyma and sclerenchyma on the basis of their cell wall

Answer 1

Paranchyma - 1) it has a primary cell wall 
                     2) cell walls are thin 
                     3) cell wall is made up of cellulose

Collemchyma-1) it also  has a primary cell wall
                     2) cell walls are thick at corners 
                     3) cell wall is made up of cellulose

Sclerenchyma-1) it has a secondary cell wall  
                      2) cell wall is very thick reducing the cellular space of the                                 cell 
                      3) cell wall is made up of "lignin"