The word flagellate also describes a particular construction (or level of organization) characteristic of many prokaryotes and eukaryotes and their means of motion.
[1] Flagella in eukaryotes are supported by microtubules in a characteristic arrangement, with nine fused pairs surrounding two central singlets.
Many parasites that affect human health or economy are flagellates in at least one stage of life cycle, such as Naegleria, Trichomonas and Plasmodium.
[citation needed]An overview of the occurrence of flagellated cells in eukaryote groups, as specialized cells of multicellular organisms or as life cycle stages, is given below (see also the article flagellum):[6][7][8] In older classifications, flagellated protozoa were grouped in Flagellata (= Mastigophora), sometimes divided into Phytoflagellata (= Phytomastigina, mostly autotrophic) and Zooflagellata (= Zoomastigina, heterotrophic).
The amoeboflagellates (e.g., the rhizarian genus Cercomonas, some amoebozoan Archamoebae, some excavate Heterolobosea) have a peculiar type of flagellate/amoeboid organization, in which cells may present flagella and pseudopods, simultaneously or sequentially, while the helioflagellates (e.g., the cercozoan heliomonads/dimorphids, the stramenopile pedinellids and ciliophryids) have a flagellate/heliozoan organization.