Collenchyma is a specialized supporting simple permanent tissue of living cells filled with protoplasm and characteristically possessing unevenly distributed thickenings of cellulose, pectin and hemicellulose on their wall. Although closely related to parenchyma, collenchyma has thicker walls and elongated cells. The cells are compactly arranged and may or may not possess intercellular spaces. It gives mechanical strength of plant parts and store food material. Sclerenchyma is considerably thick walled lignified supportive tissue characterized by the absence of living protoplasm hence, considered dead. It provides mechanical strength, save the plant from various stresses and strains and help in dehiscence of many fruits.