Definition: A landform that extends above the surrounding terrain in a limited area. A mountain is generally steeper than a hill, but there is no universally accepted standard definition for the height of a mountain or a hill although a mountain usually has an identifiable summit and a local relief of more than 300m.
Definition: A plain without trees (apart from those near rivers and lakes); it is similar to a prairie, although a prairie is generally considered as being dominated by tall grasses, while short grasses are said to be normal in the steppe. It may be semi-desert, or covered with grass or shrubs or both, depending on the season and latitude.
Definition: A wavelike sequence of muscular contraction and relaxation that passes along a tubelike structure, such as a vertebrate intestine, or the body of an earthworm
Definition: movement of an organism from one location to another using an inchworm like motion. This motion consists of extending the front part of the body and pulling the rear along the surface to meet the front.
