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The Amoebozoa are a major group of amoeboid protozoa, including the majority that move by means of internal cytoplasmic flow. Their pseudopodia are characteristically blunt and finger-like, called lobopodia. Most are unicellular, and are common in soils and aquatic habitats, with some found as symbiotes of other organisms, including several pathogens. The Amoebozoa also include the slime moulds, multinucleate or multicellular forms that produce spores and are usually visible to the unaided eye. Chaos diffluens, an amoeba. ...
Amoeba (also spelled ameba) is a genus of protozoa that moves by means of temporary projections called pseudopods, and is well-known as a representative unicellular organism. ...
Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ...
Typical phyla Rhodophyta (red algae) Chromista Heterokontophyta (heterokonts) Haptophyta Cryptophyta (cryptomonads) Alveolates Dinoflagellata Apicomplexa Ciliophora (ciliates) Excavates Euglenozoa Percolozoa Metamonada Rhizaria Radiolaria Foraminifera Cercozoa Amoebozoa Choanozoa Many others; classification varies Protists are a heterogeneous group of living things, comprising those eukaryotes that are neither animals, plants, nor fungi. ...
Lühe is a commune in the north west of Hamburg (Germany). ...
Typical orders Protostelia Protosteliida Myxogastria Liceida Echinosteliida Trichiida Stemonitida Physarida Dictyostelia Dictyosteliida Slime moulds (or slime molds in American English) are peculiar protists that normally take the form of amoebae, but under certain conditions develop fruiting bodies that release spores, superficially similar to the sporangia of fungi. ...
The pelobionts are a small group of amoebae that lack mitochondria. ...
Species Entamoeba coli Entamoeba histolytica Entamoeba invadens Endolimax nana etc. ...
Amoeba (Chaos diffluens) Foraminiferan shells Heliozoan (Actinophrys sol) Amoeboids are cells that move or feed by means of temporary projections, called pseudopods (false feet). ...
Cytoplasm is a homogeneous, generally clear jelly-like material that fills cells. ...
Pseudopods or pseudopodia (false feet) are temporary projections of eukaryotic cells. ...
Typical orders Protostelia Protosteliida Myxogastria Liceida Echinosteliida Trichiida Stemonitida Physarida Dictyostelia Dictyosteliida Slime moulds (or slime molds in American English) are peculiar protists that normally take the form of amoebae, but under certain conditions develop fruiting bodies that release spores, superficially similar to the sporangia of fungi. ...
Amoebozoa vary greatly in size. Many are only 10-20 μm in size, but they also include many of the larger protozoa. The famous species Amoeba proteus may reach 800 μm in length, and partly on account of its size is often studied as a representative cell. Multinucleate amoebae like Chaos and Pelomyxa may be several millimetres in length, and some slime moulds cover several square feet. Amoeba (also spelled ameba) is a genus of protozoa that moves by means of temporary projections called pseudopods, and is well-known as a representative unicellular organism. ...
Chaos is a genus of giant amoebae, varying from 1-5 mm in length. ...
Pelomyxa are giant amoebae, usually 500-800 μm, but occasionally passing 3 mm in length. ...
Morphology
The cell is typically divided into a granular central mass, called endoplasm, and a clear outer layer, called ectoplasm. During locomotion the endoplasm flows forwards and the endoplasm runs backwards along the outside of the cell. Many amoebae move with a definite anterior and posterior; in essence the cell functions as a single pseudopod. They usually produce numerous clear projections called subpseudopodia (or determinate pseudopodia), which have a defined length and are not directly involved in locomotion.
Other amoebozoans may form multiple indeterminate pseudopodia, which are more or less tubular and are mostly filled with granular endoplasm. The cell mass flows into a leading pseudopod, and the others ultimately retract unless it changes direction. Subpseudopodia are usually absent. In addition to a few naked forms like Amoeba and Chaos, this includes most amoebae that produce shells. These may be composed of organic materials, as in Arcella, or of collected particles cemented together, as in Difflugia, with a single opening through which the pseudopodia emerge.
The primary mode of nutrition is by phagocytosis: the cell surrounds potential food particles, sealing them into vacuoles where the may be digested and absorbed. Some amoebae have a posterior bulb called a uroid, which may serve to accumulate waste, periodically detaching from the rest of the cell. When food is scarce, most species can form cysts, which may be carried aerially and introduce them to new environments. In slime moulds, these structures are called spores, and form on stalked structures called fruiting bodies or sporangia. Phagocytosis (literally, cell eating) is a form of endocytosis where large particles are enveloped by the cell membrane of a (usually larger) cell and internalized to form a phagosome, or food vacuole. ...
Vacuoles are large membrane-bound compartments within some eukaryotic cells where they serve a variety of different functions: capturing food materials or unwanted structural debris surrounding the cell, sequestering materials that might be toxic to the cell, maintaining fluid balance (called turgor) within the cell, exporting unwanted substances from the...
This is an article about cysts in the body. ...
A sporangium (pl. ...
Most Amoebozoa lack flagella and more generally do not form microtubule-supported structures except during mitosis. However, flagella occur among the pelobionts, and many slime moulds produce biflagellate gametes. The flagella is generally anchored by a cone of microtubules, suggesting a close relationship to the opisthokonts. The mitochondria characteristically have branching tubular cristae, but have been lost among pelobionts and the parasitic entamoebids, collectively referred to as archamoebae based on the earlier assumption that the absence was primitive. A flagellum (plural, flagella) is a whip-like organelle that many unicellular organisms, and some multicellular ones, use to move about. ...
This article is in need of attention from an expert on the subject. ...
Light micrograph of a newt lung cell in early anaphase of mitosis. ...
The pelobionts are a small group of amoebae that lack mitochondria. ...
Gametes (in Greek: γαμÎτες) —also known as sex cells, or spores—are the specialized germ cells that come together during fertilization (conception) in organisms that reproduce sexually. ...
The opisthokonts are a broad group of eukaryotes, including both the animals and fungi, together with a few sorts of protists. ...
Mitochondria are visible as thread-like structures in the light microscope. ...
Cross-section of a mitochondrion, showing: (1) inner membrane, (2) outer membrane, (3) cristae, (4) matrix Cristae are the infoldings of the inner membrane of a mitochondrion. ...
Species Entamoeba coli Entamoeba histolytica Entamoeba invadens Endolimax nana etc. ...
Classification Traditionally all amoebae with lobose pseudopods were treated together as the Lobosea, placed with other amoeboids in the phylum Sarcodina or Rhizopoda, but these were considered to be unnatural groups. Structural and genetic studies identified several independent groups: the percolozoans, pelobionts, and entamoebids. In phylogenies based on rRNA their representatives were separate from other amoebae, and appeared to diverge near the base of eukaryotic evolution, as did most slime molds. The Percolozoa are a group of colorless protists including many that can transform between amoeboid, flagellate, and encysted stages, collectively referred to as schizopyrenids or amoeboflagellates. ...
A non-coding RNA (ncRNA) is any RNA molecule that functions without being translated into a protein. ...
Kingdoms Animalia - Animals Fungi Plantae - Plants Protista A eukaryote (also spelled eucaryote) is an organism with complex cells, in which the genetic material is organized into membrane-bound nuclei. ...
However, revised trees by Cavalier-Smith and Chao in 1996 suggested that the remaining lobosans do form a monophyletic group, and that the archamoebae and Mycetozoa are closely related to it, although the percolozoans are not. Subsequently they emended the older phylum Amoebozoa to refer to this supergroup. Studies based on other genes have provided strong support for the unity of this group. Patterson treated most with the testate filose amoebae as the ramicristates, based on mitochondrial similarities, but the latter are now removed to the Cercozoa. Thomas Cavalier-Smith is a professor of evolutionary biology at the University of Oxford, and is winner of the International Prize for Biology 2004 and one of the most notable researchers concerning the relationships, development, and classification of living things. ...
This is the name of two notable people: David A. Patterson (computer scientist) David J. Patterson (biologist) This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ...
The Cercozoa are a group of protists, including most amoeboids and flagellates that feed by means of filose pseudopods. ...
Amoebae are difficult to classify, and relationships within the phylum remain confused. Originally it was divided into the subphyla Conosa, comprising the archamoebae and Mycetozoa, and Lobosa, including the more typical lobose amoebae. Molecular phylogenies provide some support for this division if the Lobosa are understood to be paraphyletic. They also suggest the morphological families of naked lobosans may correspond at least partly to natural groups: In phylogenetics, a grouping of organisms is said to be paraphyletic (Greek para = near and phyle = race) if all the members of the group have a common ancestor, but the group does not include all the descendants of the most recent common ancestor of all group members. ...
However, many amoebae have not yet been studied via molecular techniques, including all those that produce shells (Arcellinida). Genera Amoeba Chaos Deuteramoeba Hydramoeba Metachaos Parachaos Polychaos Trichamoeba The Amoebidae are a family of amoebozoa, including naked amoebae that produce multiple pseudopodia of indeterminate length. ...
Genera Cashia Glaeseria Hartmannella Nolandella Saccamoeba The Hartmannellidae are a common family of amoebozoa, usually found in soils. ...
Genera Clydonella Discamoeba Lingulamoeba Pessonella Platyamoeba Unda Vannella The Vannellidae are a distinctive family of amoebozoa. ...
References - Cavalier-Smith, T. & Chao, E.E. (1996). Molecular phylogeny of the free-living archezoan Trepomonas agilis and the nature of the first eukaryote. Journal of Molecular Evolution 43: 551-562.
- Cavalier-Smith, T. (1998). A revised six-kingdom system of life. Biological Reviews of the Cambridge Philosophical Society 73: 203-266.
- David J. Patterson (1999). The Diversity of Eukaryotes. American Naturalist 145: S96-S124.
- Baldauf, S.L. et al. (2000). A kingdom-level phylogeny of eukaryotes based on combined protein data. Science 290: 972-977.
- José F. Fahrni et al. (2003). Phylogeny of Lobose Amoebae Based on Actin and Small-Subunit Ribosomal RNA Genes. Molecular Biology and Evolution 20 (11): 1881-1886.
Science is the journal of the American Association for the Advancement of Science (AAAS). ...
External links - Molecular Phylogeny of Amoeboid Protists - Tree of Amoebozoa
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