AP BIOLOGY

Detailed explanation-1: -Cork is a protective tissue with dead suberin rich cells that forms thick and waterproof covering of older stem and root. Suberin is a waterproofing waxy substance which restricts water movement.

Detailed explanation-2: -It protects the plants by acting as a cushion against any physical or mechanical injuries. It is rich in suberin, a jelly-like compound that prevents water loss from plants. It makes the plants more resistant to bacterial and fungal infections.

Detailed explanation-3: -As growth proceeds, the cork cambium forms in living cells of the epidermis, cortex, or, in some plants, phloem and produces a secondary protective tissue, the periderm.

Detailed explanation-4: -Cork tissue is also known as phellem. Cork cells are dead when mature and hence form the outer layer in stems and roots of woody plants. They are impermeable to water and gases.