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Stygamoebida
The Flabellinia are a subclass of Amoebozoa. During locomotion the cells are flattened and have a clear layer called ''hyaloplasm'' along the front margin. Some form slender subpseudopodia projecting outward from the hyaloplasm, but the cell mass does not flow into these as in true pseudopodia, and advances without a definite central axis as in the Tubulinea The Tubulinea are a major grouping of Amoebozoa, including most of the more familiar amoebae genera like ''Amoeba'', '' Arcella'', ''Difflugia'' and '' Hartmannella''. Characteristics During locomotion most Tubulinea have a roughly cylindrical f .... They also lack distinctive features like shells and flagella, and are united mainly by evidence from molecular trees. The group was originally created by Alexey Smirnov and his coauthors as the class Flabellinea, which was similar in composition to the group Discosea, proposed by Cavalier-Smith ''et al.'' (2004). In 2011, Smirnov accepted Discosea as a class and reduced F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discosea
Discosea is a class of Amoebozoa, consisting of naked amoebae with a flattened, discoid body shape. Members of the group do not produce tubular or subcylindrical pseudopodia, like amoebae of the class Tubulinea. When a discosean is in motion, a transparent layer called ''hyaloplasm'' forms at the leading edge of the cell (see lamelliopodium). In some discoseans, short "subpseudopodia" may be extended from this hyaloplasm, but the granular contents of the cell do not flow into these, as in true pseudopodia. Discosean amoebae lack hard shells, but some, like ''Cochliopodium'' and ''Korotnevella'' secrete intricate organic scales which may cover the upper (dorsal) surface of the cell. No species have flagella or flagellated stages of life. The composition of Discosea is similar to that of the class Flabellinea, proposed by Alexey Smirnov and his collaborators in 2005. However, Discosea is a more comprehensive taxon, including several groups not included in Flabellinea. In 2011, S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dermamoebida
Discosea is a class of Amoebozoa, consisting of naked amoebae with a flattened, discoid body shape. Members of the group do not produce tubular or subcylindrical pseudopodia, like amoebae of the class Tubulinea. When a discosean is in motion, a transparent layer called ''hyaloplasm'' forms at the leading edge of the cell (see lamelliopodium). In some discoseans, short "subpseudopodia" may be extended from this hyaloplasm, but the granular contents of the cell do not flow into these, as in true pseudopodia. Discosean amoebae lack hard shells, but some, like '' Cochliopodium'' and '' Korotnevella'' secrete intricate organic scales which may cover the upper (dorsal) surface of the cell. No species have flagella or flagellated stages of life. The composition of Discosea is similar to that of the class Flabellinea, proposed by Alexey Smirnov and his collaborators in 2005. However, Discosea is a more comprehensive taxon, including several groups not included in Flabellinea. In 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stygamoebida
The Flabellinia are a subclass of Amoebozoa. During locomotion the cells are flattened and have a clear layer called ''hyaloplasm'' along the front margin. Some form slender subpseudopodia projecting outward from the hyaloplasm, but the cell mass does not flow into these as in true pseudopodia, and advances without a definite central axis as in the Tubulinea The Tubulinea are a major grouping of Amoebozoa, including most of the more familiar amoebae genera like ''Amoeba'', '' Arcella'', ''Difflugia'' and '' Hartmannella''. Characteristics During locomotion most Tubulinea have a roughly cylindrical f .... They also lack distinctive features like shells and flagella, and are united mainly by evidence from molecular trees. The group was originally created by Alexey Smirnov and his coauthors as the class Flabellinea, which was similar in composition to the group Discosea, proposed by Cavalier-Smith ''et al.'' (2004). In 2011, Smirnov accepted Discosea as a class and reduced F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amoebozoa
Amoebozoa is a major taxonomic group containing about 2,400 described species of amoeboid protists, often possessing blunt, fingerlike, lobose pseudopods and tubular mitochondrial cristae. In traditional and currently no longer supported classification schemes, Amoebozoa is ranked as a phylum within either the kingdom Protista or the kingdom Protozoa. In the classification favored by the International Society of Protistologists, it is retained as an unranked " supergroup" within Eukaryota. Molecular genetic analysis supports Amoebozoa as a monophyletic clade. Modern studies of eukaryotic phylogenetic trees identify it as the sister group to Opisthokonta, another major clade which contains both fungi and animals as well as several other clades comprising some 300 species of unicellular eukaryotes. Amoebozoa and Opisthokonta are sometimes grouped together in a high-level taxon, variously named Unikonta, Amorphea or Opimoda. Amoebozoa includes many of the best-known amoeboid orga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acanthamoeba
''Acanthamoeba'' is a genus of amoeboid, amoebae that are commonly recovered from soil, fresh water, and other habitat (ecology), habitats. ''Acanthamoeba'' has two evolutive forms, the metabolically active trophozoite and a dormant, stress-resistant cyst. Trophozoites are small, usually 15 to 25 μm in length and amoeboid in shape. In nature, ''Acanthamoeba'' species are free-living bacterivores, but in certain situations, they can cause infections (acanthamebiasis) in humans and other animals. Distribution ''Acanthamoeba'' spp. are among the most prevalent protozoa found in the environment. They are distributed worldwide, and have been isolated from soil, air, sewage, seawater, chlorinated swimming pools, domestic tap water, bottled water, dental treatment units, hospitals, air-conditioning units, and contact lens cases. Additionally, they have been isolated from human skin, nasal cavities, throats, and intestines, as well as plants and other mammals. Role in disease Diseas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vannellida
The Vannellidae are a family of Amoebozoa, which are found in soil, fresh- and salt water. The most common genus is ''Vannella''. Description ''Vannellidae'' tend to be flattened and fan-shaped during motion, although some are long and narrow, and have a prominent clear margin at the anterior. In most amoebae, the endoplasm glides forward through the center of the cell, but vannellids undergo a sort of rolling motion with the outer membrane sliding around like a tank tread. These amoebae are usually 10-40 μm in size, but some are smaller or larger. ''Vannellidae'' are surrounded by an outer covering called the glycocalyx, which is generally 10-20 nm across, though the thickness varies among species. In some species, a layer of hair-like filaments called glycostyles protrudes from the glycocalyx. Taxonomy Molecular phylogenies include them in the class Flabellinia as a sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tubulinea
The Tubulinea are a major grouping of Amoebozoa, including most of the more familiar amoebae genera like ''Amoeba'', ''Arcella'', ''Difflugia'' and ''Hartmannella''. Characteristics During locomotion most Tubulinea have a roughly cylindrical form or produce numerous cylindrical pseudopods. Each cylinder advances by a single central stream of cytoplasm, granular in appearance, and has no subpseudopodia. This distinguishes them from other amoeboid groups, although in some members this is not the normal type of locomotion. Classification This class was anticipated by some biologists like Jahn, who grouped all amoebae with granular pseudopodia together, but most split the lobose amoebae into testate Testacealobosia and naked Gymnamoebia. These latter are polyphyletic, but molecular trees by Bolivar ''et al.'' identified a core monophyletic subgroup. Subsequent studies showed the testate lobose amoebae belong to the same group, which was thus renamed Lobosea ''sensu stricto'' or Tu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flagellum
A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates. A microorganism may have from one to many flagella. A gram-negative bacterium ''Helicobacter pylori'' for example uses its multiple flagella to propel itself through the mucus lining to reach the stomach epithelium, where it may cause a gastric ulcer to develop. In some bacteria the flagellum can also function as a sensory organelle, being sensitive to wetness outside the cell. Across the three domains of Bacteria, Archaea, and Eukaryota the flagellum has a different structure, protein composition, and mechanism of propulsion but shares the same function of providing motility. The Latin word means " whip" to describe its lash-like swimming motion. The flagellum in archaea is called the archaellum to note its difference from the bacterial flagellum. Eukaryotic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
