what is epidermis class 9

Epidermis is the outermost layer of cells covering an organism, in particular, the surface epithelium of the skin of an animal, overlying the dermis and the outer layer of tissue in a plant, except where it is replaced by periderm. In animals, the epidermal cells protect the underlying cells, and the waxy cuticle prevents the loss of moisture from the leaves and stems in plants. The epidermis is made up of epithelial tissue, which is the primary protective layer of the skin consisting of a keratinized stratified squamous epithelium. The epidermis serves as a barrier against water loss and infection, regulates the gas exchange mechanism, secretes metabolic chemicals, and absorbs water and vital minerals. The epidermis contains different types of cells, including keratinocytes, melanocytes, Langerhans cells, and Merkel cells.