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Flagellate
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Flagellates are cells with one or more whip-like organelles called flagella.
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Encyclopedia
Flagellates are cells with one or more whip-like organelles called flagella. Some cells in animals may be flagellate, for instance the spermatozoa of most phyla. Higher plants and fungi do not produce flagellate cells, but the closely related green algae and chytrids do. Many protists take the form of single-celled flagellates.
It describes a means of motion, and does not provide specific classification.
However, the term "flagellate" is included in other terms (such as "zooflagellate") which are more formally characterized. Another group is Dinoflagellate.
Form and behavior
Eukaryotic flagella are supported by microtubules in a characteristic arrangement, with nine fused pairs surrounding two central singlets. These arise from a basal body or kinetosome, with microtubule roots that are an important part of the cell's brain. In some, for instance, they support a cytostome or mouth, where food is ingested. The flagella often support hairs, called mastigonemes, or contain rods. Their ultrastructure plays an important role in classifying eukaryotes.
In protists and microscopic animals, flagella are generally used for propulsion. They may also be used to create a current that brings in food. In most things, one or more flagella are located at or near the anterior of the cell eg Euglena. Often there is one directed forwards and one trailing behind. Among animals, fungi, and Choanozoa, which make up a group called the opisthokonts, there is a single posterior flagellum. They are from the phylum Mastigophora. They can cause diseases and they can make their own food. For example, Trypanosome which causes the African sleeping sickness.
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