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Mycetozoa
Mycetozoa is a polyphyletic grouping of slime molds. It was originally thought to be a monophyletic clade, but in 2010 it was discovered that protostelia are a polyphyletic group within Conosa. Classification It can be divided into dictyostelid, myxogastrid, and protostelid groups. The mycetozoan groups all fit into the unikont supergroup Amoebozoa, whereas most other slime molds fit into various bikont groups ( fonticulids are opisthokonts). Utility in research The dictyostelids are used as examples of cell communication and differentiation, and may provide insights into how multicellular organisms develop. '' Physarum polycephalum'' are useful for studying cytoplasmic streaming. They have also been used to study the biochemical events that surround mitosis, since all of the nuclei in a medium-sized plasmodium divide in synchrony. It has been observed that they can find their way through mazes by spreading out and choosing the shortest path, an interesting example ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slime Mold
Slime mold or slime mould is an informal name given to a polyphyletic assemblage of unrelated eukaryotic organisms in the Stramenopiles, Rhizaria, Discoba, Amoebozoa and Holomycota clades. Most are near-microscopic; those in the Myxogastria form larger plasmodial slime molds visible to the naked eye. The slime mold life cycle includes a free-living single-celled stage and the formation of spores. Spores are often produced in macroscopic multicellular or multinucleate fruiting bodies that may be formed through aggregation or fusion; aggregation is driven by chemical signals called acrasins. Slime molds contribute to the decomposition of dead vegetation; some are parasitic. Most slime molds are terrestrial and free-living, typically in damp shady habitats such as in or on the surface of rotting wood. Some myxogastrians and protostelians are aquatic or semi-aquatic. The phytomyxea are parasitic, living inside their plant hosts. Geographically, slime molds are cosmopo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eumycetozoa
Eumycetozoa (), or true slime molds, is a diverse group of protists that behave as slime molds and develop fruiting bodies, either as sorocarps or as sporocarp (fungi), sporocarps. It is a monophyletic group or clade within the phylum Amoebozoa that contains the Myxogastria, myxogastrids, dictyostelids and Protosporangiida, protosporangiids. Characteristics Eumycetozoa is a clade that includes three groups of amoebozoan protists: Myxogastria, Dictyostelia and Protosporangiida—also known as Myxomycetes, Dictyosteliomycetes and Ceratiomyxomycetes, respectively. It is defined on a Phylogenetic nomenclature#Phylogenetic definitions of clade names, node-based approach as the least inclusive clade containing the species ''Dictyostelium discoideum'' (a dictyostelid), ''Physarum polycephalum'' (a myxogastrid) and ''Ceratiomyxa fruticulosa'' (a protosporangiid). All known members of Eumycetozoa generate fruiting bodies, either as sorocarps (in dictyostelids) or as sporocarp (fungi), s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myxogastria
Myxogastria/Myxogastrea (myxogastrids, ICZN) or Myxomycetes ( ICN) is a class of slime molds that contains 5 orders, 14 families, 62 genera, and 888 species. They are colloquially known as the ''plasmodial'' or ''acellular'' slime moulds. All species pass through several very different morphologic phases, such as microscopic individual cells, slimy amorphous organisms visible with the naked eye, and conspicuously shaped fruit bodies. Although they are monocellular, they can reach immense widths and weights: in extreme cases they can be up to across and weigh up to . The class Myxogastria is distributed worldwide, but it is more common in temperate regions where it has a higher biodiversity than in polar regions, the subtropics, or the tropics. They are mainly found in open forests, but also in extreme regions such as deserts, under snow blankets, or underwater. They also occur on the bark of trees, sometimes high in the canopy. These are known as cort ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conosa
Conosa is a grouping of Amoebozoa. It is subdivided into three groups: Archamoeba, Variosea and Mycetozoa. In some classifications, the mycetozoan Myxogastria and Dictyostelia are united in Macromycetozoa (= Eumycetozoa). Conosa includes the species '' Dictyostelium discoideum,'' a social amoeba, and '' Entamoeba histolytica'', a human pathogen, among others. Conosa are morphologically defined by a conical microtubular structure, and have been found to be monophyletic. Characteristics The Conosa group was first proposed by Thomas Cavalier-Smith in 1998 as a subphylum of Amoebozoa. Cavalier-Smith originally separated this group into two infraphyla: Archamoebae and Mycetozoa. Notable characteristics of these two groups are that Mycetozoa are free living, while Archamoebae are amitochondrial. This clade is morphologically defined by their complex microtubular skeleton that forms a partial or complete cone. They have a monolayer of microtubules that surround at least some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amoebozoa
Amoebozoa is a major Taxonomy (biology), taxonomic group containing about 2,400 described species of Amoeba, amoeboid protists, often possessing blunt, fingerlike, Pseudopod#Morphology, lobose pseudopods and tubular mitochondrial cristae. In traditional classification schemes, Amoebozoa is usually ranked as a phylum within either the kingdom (biology), kingdom Protista or the kingdom Protozoa. In the classification favored by the International Society of Protistologists, it is retained as an unranked "supergroup (biology), supergroup" within Eukaryota. Molecular genetics, 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, named Amorphea. Amoeboz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protosteliales
''Protostelium'' is a genus of protosteloid amoebozoans, i.e., amoebae capable of forming simple fruiting bodies composed of a stalk and a ball of spores. It contains numerous species, including '' P. aurantium'', which was initially classified in a different genus ''Planoprotostelium''. Phylogenetic analyses revealed that ''Planoprotostelium'' branches from within the genus ''Protostelium'', making them synonyms. The genus is placed in the family Protosteliidae within the monotypic order Protosteliida, which is part of a larger group of amoebozoans known as Variosea. Classification Many species from the genus ''Protostelium'' have been transferred over time to other protosteloid genera. The following species remain: * ''Protostelium apiculatum'' * ''Protostelium aurantium'' (=''Planoprotostelium aurantium'' ) * ''Protostelium mycophaga'' * ''Protostelium nocturnum'' * ''Protostelium okumukumu ''Protostelium okumukumu'' is a species of ''Protostelium'' found in Hawaii and N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trichiida
Trichiales (synonymous with Trichiida) is an order of slime moulds in the phylum Amoebozoa. Trichiales is one of five orders in the group Myxomycetes (also called Myxogastria), or the true plasmodial slime molds. It is also currently categorized under the superorder Lucisporidia with its sister group, Liceales. The order was first described by Thomas MacBride in 1922, and has retained the same name and status as a defined order in present phylogeny. In the plasmodium form, members of Trichiales lack a columella but have a well-developed capillitium for spore dispersal. The shape and details of the capillitium are used to define families within the order. Spores are brightly coloured, ranging from clear, white and yellow to pink and red-brown tones. The order currently has 4 families, 14 genera and 174 species. Recent molecular research has shown that while Trichiales probably represents a true taxonomic group, its sister group Liceales is likely paraphyletic, and it has been sugge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multicellular Organisms
A multicellular organism is an organism that consists of more than one cell, unlike unicellular organisms. All species of animals, land plants and most fungi are multicellular, as are many algae, whereas a few organisms are partially uni- and partially multicellular, like slime molds and social amoebae such as the genus ''Dictyostelium''. Multicellular organisms arise in various ways, for example by cell division or by aggregation of many single cells. Colonial organisms are the result of many identical individuals joining together to form a colony. However, it can often be hard to separate colonial protists from true multicellular organisms, because the two concepts are not distinct; colonial protists have been dubbed "pluricellular" rather than "multicellular". There are also macroscopic organisms that are multinucleate though technically unicellular, such as the Xenophyophorea that can reach 20 cm. Evolutionary history Occurrence Multicellularity has evolved indepen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unikont
Amorphea is a taxonomic supergroup that includes the basal Amoebozoa and Obazoa. That latter contains the Opisthokonta, which includes the fungi, animals and the choanoflagellates. The taxonomic affinities of the members of this clade were originally described and proposed by Thomas Cavalier-Smith in 2002. The International Society of Protistologists, the recognised body for taxonomy of protozoa, recommended in 2012 that the term Unikont be changed to Amorphea because the name "Unikont" is based on a hypothesized synapomorphy that the ISOP authors and other scientists later rejected. It includes amoebozoa, opisthokonts, and apusomonads. Taxonomic revisions within this group Thomas Cavalier-Smith proposed two new phyla: Sulcozoa, which consists of the subphyla Apusozoa ( Apusomonadida and Breviatea), and Varisulca, which includes the subphyla Diphyllatea, Discocelida, Mantamonadidae, Planomonadida and Rigifilida. Further work by Cavalier-Smith showed that Sulcozoa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitosis
Mitosis () is a part of the cell cycle in eukaryote, eukaryotic cells in which replicated chromosomes are separated into two new Cell nucleus, nuclei. Cell division by mitosis is an equational division which gives rise to genetically identical cells in which the total number of chromosomes is maintained. Mitosis is preceded by the S phase of interphase (during which DNA replication occurs) and is followed by telophase and cytokinesis, which divide the cytoplasm, organelles, and cell membrane of one cell into two new cell (biology), cells containing roughly equal shares of these cellular components. The different stages of mitosis altogether define the mitotic phase (M phase) of a cell cycle—the cell division, division of the mother cell into two daughter cells genetically identical to each other. The process of mitosis is divided into stages corresponding to the completion of one set of activities and the start of the next. These stages are preprophase (specific to plant ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
