Claw A claw is a curved, often sharp appendage at the tip of a digit in many vertebrates and some invertebrates, used for grasping, digging, defense and other functions; made chiefly of…
Keratin: structure, functions, and biological roles Keratin Keratin is a family of fibrous proteins that form hair, nails, horns, feathers and other tough, insoluble structures in animals. This article explains its types, formation, propert…
