CBSE Class 9 Answered

Cork is a nonliving, water-resistant protective tissue that is formed on the outside of the cork cambium in the woody stems and roots of many seed plants. The cork cells are compactly arranged without any intercellular spaces. The walls of these cells are thickened due to the deposition of an organic substance called suberin, which makes these cells impermeable to water and gases. Cork is protective in function and prevents dessication, mechanical injury and infection.

When plants age. the epidermis is replaced by a strip of secondary meristem called cork cambium, outside of which is formed the cork.