heat definition In physics, a form of energy associated with the movement of atoms and molecules in any material. The higher the temperature of a material, the faster the atoms are moving, and hence the greater the amount of energy present as heat.
Cilia (singular: cilium) are microscopic, hair-like structures that extend outwardfrom the surface of manyanimal cells. These structures are important in the cell cycle and replication, and cilia play a vital part in human and animal development and in everyday life. A typical cilium is between one and ten micrometers long, and usually less than one micrometer wide.
Cilia are similar to flagella in structure and function, but a cilium is shorter and moves differently. A ciliated cell usually has hundreds or thousands of cilia, which move in unison like little oars.Sometimes a cell will also use cilia to funnel food into an oral groove. flagellum is a whip-like structure that allows a cell to move. They are found in all three domains of the living world: bacteria, archaea, and eukaryota. While all three types of flagella are used for locomotion, they are structurally very different.