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Hemimastigid
The Apusozoa are an Obazoa phylum comprising several genera of flagellate eukaryotes. They are usually around 5–20 μm in size, and occur in soils and aquatic habitats, where they feed on bacteria. They are grouped together based on the presence of an organic shell or theca under the dorsal surface of the cell. The name derives from the Ancient Greek words for footless () and animal (). This phylum is currently defined as containing the Breviata and the Apusomonadida. However, it currently usually is viewed as paraphyletic, with the Breviata as more basal. The opisthokonts appear to have emerged as sister of the apusomonadida. It has been suggested that the Mantamonadida be classified in Apusozoa. The ancyromonadida appear to be Varisulca Varisulca was a proposed basal Podiate taxon. It encompassed several lineages of heterotrophic protists, most notably the ancyromonads (planomonads), collodictyonids (diphylleids), rigifilids (''Rigifila'', ''Micronuclearia'') and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flagellate
A flagellate is a cell or organism with one or more whip-like appendages called flagella. The word ''flagellate'' also describes a particular construction (or level of organization) characteristic of many prokaryotes and eukaryotes and their means of motion. The term presently does not imply any specific relationship or classification of the organisms that possess flagella. However, the term "flagellate" is included in other terms (such as "dinoflagellate" and "choanoflagellata") which are more formally characterized. Form and behavior Flagella in eukaryotes are supported by microtubules in a characteristic arrangement, with nine fused pairs surrounding two central singlets. These arise from a basal body. In some flagellates, flagella direct food into a cytostome or mouth, where food is ingested. Flagella often support hairs, called mastigonemes, or contain rods. Their ultrastructure plays an important role in classifying eukaryotes. Among protoctists and microscopic anima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apusozoa
The Apusozoa are an Obazoa phylum comprising several genera of flagellate eukaryotes. They are usually around 5–20 μm in size, and occur in soils and aquatic habitats, where they feed on bacteria. They are grouped together based on the presence of an organic shell or theca under the dorsal surface of the cell. The name derives from the Ancient Greek words for footless () and animal (). This phylum is currently defined as containing the Breviata and the Apusomonadida. However, it currently usually is viewed as paraphyletic, with the Breviata as more basal. The opisthokonts appear to have emerged as sister of the apusomonadida. It has been suggested that the Mantamonadida be classified in Apusozoa. The ancyromonadida appear to be Varisulca, Planomonadida, shifting them possibly more basal than the Amoebozoa, or less basal. While some classification systems have placed Hemimastigida in Apusozoa, 2018 research indicated that hemimastigotes (/Hemimastix/Spironemidae) are thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apusomonas
''Apusomonas'' is a genus of Apusozoa The Apusozoa are an Obazoa phylum comprising several genera of flagellate eukaryotes. They are usually around 5–20 μm in size, and occur in soils and aquatic habitats, where they feed on bacteria. They are grouped together based on the prese ... erected by A. G. Aléxéieff in 1924. It includes the species ''Apusomonas proboscidea''. References Apusomonadida Eukaryote genera {{Unikont-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemimastigida
Spironemidae is a family of heterotrophic flagellates, in the group Hemimastigophora. They vary in size and shape from the ellipsoid ''Hemimastix amphikineta'' (14 × 7 μm) to the vermiform ''Spironema terricola'' (43 × 3 μm), and are united by the possession of two rows of cilia, called kineties. Phylogenomic analysis shows that Hemimastigophora are a distinct and ancient lineage of eukaryotic organisms, forming a possible sister clade to the supergroup Diaphoretickes. Taxonomy * Order Hemimastigida Foissner, Blatterer & Foissner 1988 [Hemimastigophora Foissner, Blatterer & Foissner 1988 sensu Cavalier-Smith 1993; Hemimastigea Foissner, Blatterer & Foissner 1988; Hemimastigidea] ** Family Spironematellidae *** Genus ''Hemimastix'' Foissner, Blatterer & Foissner, 1988 **** Species '' H. amphikineta'' Foissner, Blatterer & Foissner, 1988 **** Species '' H. kukwesjijk'' Eglit & Simpson, 2018 *** Genus ''Stereonema'' Foissner& Foissner, 1993 non ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crista
A crista (; plural cristae) is a fold in the inner membrane of a mitochondrion. The name is from the Latin for ''crest'' or ''plume'', and it gives the inner membrane its characteristic wrinkled shape, providing a large amount of surface area for chemical reactions to occur on. This aids aerobic cellular respiration, because the mitochondrion requires oxygen. Cristae are studded with proteins, including ATP synthase and a variety of cytochromes. Background With the discovery of the dual-membrane nature of mitochondria, the pioneers of mitochondrial ultrastructural research proposed different models for the organization of the mitochondrial inner membrane. Three models proposed were: *Baffle model – According to Palade (1953), the mitochondrial inner membrane is convoluted in a baffle-like manner with broad openings towards the intra-cristal space. This model entered most textbooks and was widely believed for a long time. *Septa model – Sjöstrand (1953) suggested that she ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitochondrion
A mitochondrion (; ) is an organelle found in the cells of most Eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used throughout the cell as a source of chemical energy. They were discovered by Albert von Kölliker in 1857 in the voluntary muscles of insects. The term ''mitochondrion'' was coined by Carl Benda in 1898. The mitochondrion is popularly nicknamed the "powerhouse of the cell", a phrase coined by Philip Siekevitz in a 1957 article of the same name. Some cells in some multicellular organisms lack mitochondria (for example, mature mammalian red blood cells). A large number of unicellular organisms, such as microsporidia, parabasalids and diplomonads, have reduced or transformed their mitochondria into other structures. One eukaryote, ''Monocercomonoides'', is known to have completely lost its mitochondria, and one multicellular organism, '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supra-kingdom
In biology, a kingdom is the second highest taxonomic rank, just below domain. Kingdoms are divided into smaller groups called phyla. Traditionally, some textbooks from the United States and Canada used a system of six kingdoms (Animalia, Plantae, Fungi, Protista, Archaea/Archaebacteria, and Bacteria/Eubacteria) while textbooks in Great Britain, India, Greece, Brazil and other countries use five kingdoms only (Animalia, Plantae, Fungi, Protista and Monera). Some recent classifications based on modern cladistics have explicitly abandoned the term ''kingdom'', noting that some traditional kingdoms are not monophyletic, meaning that they do not consist of all the descendants of a common ancestor. The terms ''flora'' (for plants), ''fauna'' (for animals), and, in the 21st century, ''funga'' (for fungi) are also used for life present in a particular region or time. Definition and associated terms When Carl Linnaeus introduced the rank-based system of nomenclature into biology in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spironemidae
Spironemidae is a family of heterotrophic flagellates, in the group Hemimastigophora. They vary in size and shape from the ellipsoid ''Hemimastix amphikineta'' (14 × 7 μm) to the vermiform ''Spironema terricola'' (43 × 3 μm), and are united by the possession of two rows of cilia, called kineties. Phylogenomic analysis shows that Hemimastigophora are a distinct and ancient lineage of eukaryotic organisms, forming a possible sister clade to the supergroup Diaphoretickes. Taxonomy * Order Hemimastigida Foissner, Blatterer & Foissner 1988 [Hemimastigophora Foissner, Blatterer & Foissner 1988 sensu Cavalier-Smith 1993; Hemimastigea Foissner, Blatterer & Foissner 1988; Hemimastigidea] ** Family Spironematellidae *** Genus ''Hemimastix'' Foissner, Blatterer & Foissner, 1988 **** Species '' H. amphikineta'' Foissner, Blatterer & Foissner, 1988 **** Species '' H. kukwesjijk'' Eglit & Simpson, 2018 *** Genus ''Stereonema'' Foissner& Foissner, 1993 non ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemimastix
Spironemidae is a family of heterotrophic flagellates, in the group Hemimastigophora. They vary in size and shape from the ellipsoid ''Hemimastix amphikineta'' (14 × 7 μm) to the vermiform ''Spironema terricola'' (43 × 3 μm), and are united by the possession of two rows of cilia, called kineties. Phylogenomic analysis shows that Hemimastigophora are a distinct and ancient lineage of eukaryotic organisms, forming a possible sister clade to the supergroup Diaphoretickes. Taxonomy * Order Hemimastigida Foissner, Blatterer & Foissner 1988 [Hemimastigophora Foissner, Blatterer & Foissner 1988 sensu Cavalier-Smith 1993; Hemimastigea Foissner, Blatterer & Foissner 1988; Hemimastigidea] ** Family Spironematellidae *** Genus '' Hemimastix'' Foissner, Blatterer & Foissner, 1988 **** Species '' H. amphikineta'' Foissner, Blatterer & Foissner, 1988 **** Species '' H. kukwesjijk'' Eglit & Simpson, 2018 *** Genus ''Stereonema'' Foissner& Foissner, 1993 non ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemimastigote
Hemimastigophora is a group of single-celled eukaryotic organisms with a single family, Spironemidae, first identified in 1988. Over the next 30 years, different authors proposed placing these organisms in various branches of the eukaryotes. In 2018 Lax ''et al''. reported the first genetic information for Spironemidae, and suggest that they are from an ancient lineage of eukaryotes which constitute a separate clade from all other eukaryotic kingdoms. It is potentially related to the Telonemia. History of classification Hemimastigophora was established in 1988 by Foissner ''et al''., as a new phylum with a single family, Spironemidae. Its placement on the eukaryote tree of life was unclear, but the authors suggested that the structure of its pellicle and cell nucleus indicated a close relationship with Euglenozoa. For 30 years after the description of the group, no genetic information was available. During that time, researchers proposed that it should be classified in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancyromonadida
Ancyromonadida or Planomonadida is a small group of biflagellated protists found in the soil and in aquatic habitats, where they feed on bacteria.Cavalier-Smith, T. (2013)Early evolution of eukaryote feeding modes, cell structural diversity, and classification of the protozoan phyla Loukozoa, Sulcozoa, and Choanozoa European journal of protistology, 49(2), 115-178. Includes freshwater or marine organisms, benthic, dorsoventrally compressed and with two unequal flagellae, each emerging from a separate pocket. The apical anterior flagellum can be very thin or end in the cell membrane, while the posterior flagellum is long and is inserted ventrally or laterally. The cell membrane is supported by a thin single layer teak and the mitochondrial crests are discoidal / flat. The group's placement is doubtful, as it seems to fall outside the five supergroups of eukaryotes. Cavalier-Smith considers that they constitute a basal group to Amoebozoa and Opisthokonta and places it together w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Varisulca
Varisulca was a proposed basal Podiate taxon. It encompassed several lineages of heterotrophic protists, most notably the ancyromonads (planomonads), collodictyonids (diphylleids), rigifilids (''Rigifila'', ''Micronuclearia'') and mantamonadids. Recent evidence suggests that the latter three are closely related to each other, forming a clade called CRuMs, but that this is unlikely to be specifically related to ancyromonads Cavalier-Smith had proposed the new subphylum Varisulca which consists of the classes Hilomonadea, Diphyllatea and Glissodiscea. The validity of this proposed taxonomy has yet to ruled upon by the Society of Protistologists. It is unlikely to be widely accepted, since Varisulca appears to be paraphyletic or polyphyletic (ancyromonads are not inferred to be the sister group to CRuMs). Glissodiscea and Multirhiza (a taxon encompassing Diphyllatea and Glissodiscea) also appear paraphyletic or polyphyletic, since ''Mantamonas'' belongs to CRuMs but ancyrom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
