Question

List the characteristics of cork. How are they formed? Mention their role.

Answer 1

Hint: The cork is the part of the periderm of the plant which helps to protect the inner tissues of the plants from many unfavourable conditions and the conditions which are harmful to plants.

Complete answer:
The cork is defined as a part of the periderm that protects the inner plant tissues from different conditions like mechanical injuries, water loss, and pathogens. The cork is known to be composed of cells that are dead at maturity and filled with air, tannins, or resins.
-As the plants get older day by day, the outer protective tissue which is known as the epidermis undergoes certain changes. A strip of the secondary meristem is very commonly called phellogen or cork cambium replaces the epidermis of the stem.
-Cork cambium is made up of simple tissue, the cells are rectangular in shape and their protoplast has many vacuoles and contains tannins and chloroplasts. The cork cambium gives off new cells on its every side, thus forming cork (phellem) on the outer side and therefore the secondary cortex or phelloderm on the inner side.
The layer of the cells which is cut by cork cambium on the outer side will ultimately become several layered thick corks and is considered as the bark of the trees. Cells of cork are dead and are found to be compactly arranged without intercellular spaces.
-The walls of cells of the cork are found to be heavily thickened with a substance which is organic and is also known to be a fatty substance, commonly known as suberin, which makes these cells impermeable to water and different gases.
Cork is protective in function. Its cells prevent loss of water from the plant body, which is a common term known as desiccation. Infection and mechanical injury. It's light and doesn't erupt easily, thanks to these properties, cork is employed as insulators, shock-absorbers, linoleum (used as flooring), and sports goods for example in making of shuttlecocks, cricket balls, wooden paddles of Ping-Pong, etc.).

Note: The commercial cork is usually obtained from the surface of the stem of the tree which is commonly known as the Quercus suber and is mainly found in Southern Europe and North Africa.