Amoeben

An amoeba (plural amoebae) is a unicellular eukaryote in the group Amoebozoa. Note: in German-language usage, the plural is Amoeben. Amoebae are known for their flexible shape, produced by pseudopods that form as the cytoplasm streams. They move and feed by amoeboid movement and phagocytosis. Most lack a rigid cell wall; their cytoplasm typically consists of a clear ectoplasm and a granular endoplasm, and a nucleus houses the genetic material.

Nutrition and reproduction: They feed by phagocytosis, engulfing bacteria, algae, or detritus into food vacuoles for digestion. Reproduction is primarily asexual, by binary fission; some species can form resistant cysts to survive unfavorable conditions.

Habitat and ecology: Amoebae occur worldwide in soil, freshwater, and marine environments, often in moist environments or decaying organic matter. Free-living amoebae are common; some are opportunistic or obligate parasites, such as Entamoeba histolytica in humans.

Medical and research relevance: Several species affect human health, including Entamoeba histolytica, which causes amebiasis, and Naegleria fowleri, linked to rare brain infections. In biology, amoebae serve as simple model systems for studying cell locomotion, cytoskeleton dynamics, and phagocytosis; Amoeba proteus is a frequently used laboratory species.