Amoeboid in the context of "Chlorarachniophyte"

The Rhizaria are a diverse and species-rich clade of mostly unicellular eukaryotes. Except for the chlorarachniophytes and three species in the genus Paulinella in the phylum Cercozoa, they are all non-photosynthetic, but many Foraminifera and Radiolaria have a symbiotic relationship with unicellular algae. A multicellular form, Guttulinopsis vulgaris, a cellular slime mold, has been described. This group was used by Cavalier-Smith in 2002, although the term "Rhizaria" had been long used for clades within the currently recognized taxon.

Being described mainly from rDNA sequences, they vary considerably in form, having no clear morphological distinctive characters (synapomorphies), but for the most part they are amoeboids with filose, reticulose, or microtubule-supported pseudopods. In the absence of an apomorphy, the group is ill-defined, and its composition has been very fluid. Some Rhizaria possess mineral exoskeletons (thecae or loricas), which are in different clades within Rhizaria made out of opal (SiO₂), celestite (SrSO₄), or calcite (CaCO₃).

Dictyostelium discoideum is a species of soil-dwelling amoeba belonging to the phylum Amoebozoa, infraphylum Mycetozoa. Commonly referred to as slime mold, D. discoideum is a eukaryote that transitions from a collection of unicellular amoebae into a multicellular slug and then into a fruiting body within its lifetime. Its unique asexual life cycle consists of four stages: vegetative, aggregation, migration, and culmination. The life cycle of D. discoideum is relatively short, which allows for timely viewing of all stages. The cells involved in the life cycle undergo movement, chemical signaling, and development, which are applicable to human cancer research. The simplicity of its life cycle makes D. discoideum a valuable model organism to study genetic, cellular, and biochemical processes in other organisms.

Chaos is a genus of single-celled amoeboid organisms in the family Amoebidae. The largest and most-known species, the so-called "giant amoeba" (Chaos carolinense), can reach lengths up to 5 mm, although most specimens fall between 1 and 3 mm.

Members of this genus closely resemble those of the genus Amoeba and share the same general morphology, producing numerous cylindrical pseudopods, each of which is rounded at the tip. However, while Amoeba have a single nucleus, Chaos can have as many as a thousand. Because of this attribute, C. carolinense was once placed in the genus Pelomyxa alongside the giant multinucleate amoeba Pelomyxa palustris. Recently, molecular phylogenetic studies of this species have confirmed the view of some earlier researchers that it is more closely related to Amoeba than to Pelomyxa. The species is now placed in the independent genus Chaos, a sister group to Amoeba.

Paulinella is a genus of at least twelve species including both freshwater and marine amoeboids. Like many members of euglyphids it is covered by rows of siliceous scales, and use filose pseudopods to crawl over the substrate of the benthic zone. Species within the group can be distinguished by features like the overall shell dimensions, the number of vertical scale rows (3-5), the number of scales per row (7–14) and the number of oral scales.

Phagocytes are cells that protect the body by ingesting harmful foreign particles, bacteria, and dead or dying cells. They include monocytes, macrophages, neutrophils, tissue dendritic cells, and mast cells. Their name comes from the Greek phagein, "to eat" or "devour", and "-cyte", the suffix in biology denoting "cell", from the Greek kutos, "hollow vessel". They are essential for fighting infections and for subsequent immunity. Phagocytes are important throughout the animal kingdom and are highly developed within vertebrates. One litre of human blood contains about six billion phagocytes. They were discovered in 1882 by Ilya Ilyich Mechnikov while he was studying starfish larvae. Mechnikov was awarded the 1908 Nobel Prize in Physiology or Medicine for his discovery. Phagocytes occur in many species; some amoebae behave like macrophage phagocytes, which suggests that phagocytes appeared early in the evolution of life.

Phagocytes of humans and other animals are called "professional" or "non-professional" depending on how effective they are at phagocytosis. The professional phagocytes include many types of white blood cells (such as neutrophils, monocytes, macrophages, mast cells, and dendritic cells). The main difference between professional and non-professional phagocytes is that the professional phagocytes have molecules called receptors on their surfaces that can detect harmful objects, such as bacteria, that are not normally found in the body. Non-professional phagocytes do not have efficient phagocytic receptors, such as those for opsonins. Phagocytes are crucial in fighting infections, as well as in maintaining healthy tissues by removing dead and dying cells that have reached the end of their lifespan.

Acanthamoeba is a genus of amoebae that are commonly recovered from soil, fresh water, and other habitats.The genus Acanthamoeba has two stages in its life cycle, the metabolically active trophozoite stage and a dormant, stress-resistant cyst stage. In nature, Acanthamoeba species are generally free-living bacterivores. However, they are also opportunistic pathogens able to cause serious and potentially fatal infections in humans and other animals.

Amoeba is a genus of single-celled amoeboids in the family Amoebidae. The type species of the genus is Amoeba proteus, a common freshwater organism, widely studied in classrooms and laboratories.