An
amoeba (; rarely spelled
amœba, US English commonly
ameba; plural
am(o)ebas or
am(o)ebae ), often called
amoeboid, is a type of
cell or
organism which has the ability to alter its shape, primarily by extending and retracting
pseudopods. Amoebas do not form a single
taxonomic group; instead, they are found in every major
lineage of
eukaryotic organisms. Amoeboid cells occur not only among the
protozoa, but also in
fungi,
algae, and
animals.