characterized by concepts or the forming of concepts a drawing intended to explain how something works the distance across the center of an object a protein made by cells very clear; nothing hidden to make easier a part of a whole. flat or level part of something an action that is answered by a reaction, verbal or physical a document, a piece of writing to bring about an agreement between persons or groups, act as a helper at (or near) the middle point the smallest possible the study of the forms and structures of plants, animals and words to cover something else a round 3D object. e.g. a ball building something complex from simple parts something that is said differing, especially from something of the same general kind.