Source:http://linkedlifedata.com/resource/umls/id/C1178985
GO: Any constituent part of a flagellum, a long whiplike or feathery structure borne either singly or in groups by the motile cells of many bacteria and unicellular eukaryotes and by the motile male gametes of many eukaryotic organisms, which propel the cell through a liquid medium. [GOC:jl]