[[Image:BacterialFlagellum.jpg|thumb|200px|right|[[flagellum|Bacterial Flagellum]] flagellum with rotary motor, courtesy of Access Research Network (Art Battson)]]
A '''flagellum''' is a long, tail-like [[organelle]] in a [[cell]] that allows a cell to move around. It is made up of [[microtubule]]s and surrounded by a [[plasma]] [[membrane]].