An amoeba, often called an amoeboid, is a type of cell or unicellular organism with the ability to alter its shape, primarily by extending and retracting pseudopods. Amoebae 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. Microbiologists often use the terms "amoeboid" and "amoeba" interchangeably for any organism that exhibits amoeboid movement. In older classification systems, most amoebae were placed in the class or subphylum Sarcodina, a grouping of single-celled organisms that possess pseudopods or move by protoplasmic flow. However, molecular phylogenetic studies have shown that Sarcodina is not a monophyletic group whose members share common descent. Consequently, amoeboid organisms are no longer classified together in one group.

Read more in the app

Man in Florida killed by rare, brain-eating amoeba Naegleria fowleri

Repurposed drug battles ‘brain-eating’ amoeba

Nevada boy dies of rare brain-eating amoeba infection after swimming in Lake Mead

Brain-Eating Amoeba Caused Nebraska Child’s Death, Health Officials Say

Nebraska child likely died of a brain-eating-amoeba infection

What is an amoeba?

Boy dies from rare 'brain-eating' amoeba found in splash pad at Texas park

Child dies from rare brain-eating amoeba in California

Brain-Eating Amoeba Kills 7-Year-Old Boy In California

Floating Fire Ant Rafts Form Mesmerizing Amoeba-Like Shapes. Researchers say the morphing colonies help ants feel for solid land in a flooded environment—and might inspire swarming robots one day

Amoeba biology reveals potential treatment target for lung disease

Amoeba biology reveals potential treatment target for lung disease