Question

epidermis and cork cells are called protective tissue why

Answer 1

 epidermis  is a single layer of cells that covers the leaves, flowers, roots and stems of plants. It forms a boundary between the plant and the external environment. The epidermis serves several functions: it protects against water loss, regulates gas exchange, secretes metabolic compounds. Cork cambium (pl. cambia or cambiums) is a tissue found in many vascular plants as part of the periderm. The cork cambium is a lateral meristem and is used to protect the body.

Answer 2

The entire surface of a plant has this outer covering of epidermis. It protects all the parts of the plant. Epidermal cells on the aerial parts of the plant often secrete a waxy, water resistant later on their outer surface. This aids in protection against loss of water, mechanical injury and invasion by parasitic fungi.