A protein-based, flexible, whip-like organ of locomotion found on some microorganisms. With these, microorganisms are able to swim. Flagella are usually very long and there are usually only one or two per cell. The tails of sperm cells are examples of flagella. Flagella are used in the swimming motion of bacteria towards sources of nutrients in a process called chemotaxis. Singular: flagellum.
Long thin filamentous attachments which confer the power of locomotion on motile species of bacteria, parasites, etc. If attached to one or both ends of an organism they are described as ‘polar’; if along its length as ‘peritrichous’. The flagella are the source of the H antigens by means of which some motile species and sub-species may be identified. Flagella are normally assumed present when a given bacteriological species is motile, otherwise they are demonstrable by electron microscopy or (with care) by tannic acid – basic fuchsin staining for normal light microscopy.
Slender, hair-like extensions used by bacilli and spirilla for locomotion (moving about).