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

Parenchyma	Collenchyma
(i) These are thin and cellulose walled cells.	(i) It is thick and bulky due to excess. Deposition of cellulose and pectic substances at the corners.
(ii) It is a soft tissue.	(ii) It is soft as well as strong tissue.
(iii) It performs the function of storing food.	(iii) It provides mechanical support.
(iv) It is alive because it has a lot of intercellular space.	(iv) It does not have intercellular space.
(v) It is found in almost all parts of the plants.	(v) It is not found in monocot plants.

Collenchyma	Sclerenchyma
(i) This tissue is made up of living cells	(i) This tissue is made up of dead cells
(ii) It is metabolically active in which protoplasm is found	(ii) These are dead cells and do not contain protoplasm.
(iii) Due to the deposition of cellulose and pectic substances at their corners, they are bulky	(iii) Their cells have a uniform thickening and this is due to the presence of lignin.
(iv) This tissue provides flexible firmness (or rigidity)	(iv) This tissue provides mechanical strength to all parts of plants.

Chapter 6