Question

External protective tissues of plants are (of dicot stem are)

• A. Cork and pericycle
• B. Cortex and epidermis
• C. Pericycle and cortex
• D. Epidermis and cork

Answer 1

The correct option is D Epidermis and cork

During extrastellar secondary growth, the epidermis and pericycle, with parenchyma or collenchyma cells acquire secondary meristematic property by de-differentiation and is called as phellogen or cork cambium. The outer layer of this cambium gradually lose their protoplast and become dead and their cell walls become thickened. These cells constitute cork or phellem. The phelloderm, phellogen and phellem form the primary covering layer when the epidermis gets ruptured.