|
Bikont
A bikont ("two flagella") is any of the eukaryotic organisms classified in the group Bikonta. Many single-celled members of the group, and the presumed ancestor, have two flagella. Enzymes Another shared trait of bikonts is the fusion of two genes into a single unit: the genes for thymidylate synthase (TS) and dihydrofolate reductase (DHFR) encode a single protein with two functions. The genes are separately translated in unikonts. Relationships Some research suggests that a unikont (a eukaryotic cell with a single flagellum) was the ancestor of opisthokonts (Animals, Fungi, and related forms) and Amoebozoa, and a bikont was the ancestor of Archaeplastida (Plants and relatives), Excavata, Rhizaria, and Chromalveolata. Cavalier-Smith has suggested that Apusozoa, which are typically considered ''incertae sedis'', are in fact bikonts. Relationships within the bikonts are not yet clear. Cavalier-Smith has grouped the Excavata and Rhizaria into the Cabozoa and the Archaeplastid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corticata
Corticata ("one with a cortex"), in the classification of eukaryotes (living organisms with a cell nucleus), is a clade suggested by Thomas Cavalier-Smith to encompass the eukaryote supergroups of the following two groups: * Plantae, or Archaeplastida (plants, red algae, green algae, and glaucophytes) * Chromalveolata (a group including kelp, water moulds, ciliates, dinoflagellates, and other organisms) Cavalier-Smith currently includes Rhizaria as well, resulting in an equivalency to Diaphoretickes. See also *Bikont A bikont ("two flagella") is any of the eukaryotic organisms classified in the group Bikonta. Many single-celled members of the group, and the presumed ancestor, have two flagella. Enzymes Another shared trait of bikonts is the fusion of two ge ... * Cabozoa References Bikont unranked clades Diaphoretickes {{Bikont-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diaphoretickes
Diaphoretickes () is a major group of eukaryotic organisms, with over 400,000 species. The majority of the earth's biomass that carries out photosynthesis belongs to Diaphoretickes. Diaphoretickes includes: * Archaeplastida (comprising red algae, glaucophytes, and green algae & land plants) * Cryptista * Haptista * Hemimastigophora * SAR supergroup (consisting of stramenopiles+alveolates+Rhizaria) * Telonemia Where Chromista is used as a taxon, its member groups all fall within Diaphoretickes. In 2012 Diaphoretickes received the following phylogenetic definition: :"The most inclusive clade containing ''Bigelowiella natans'' Moestrup & Sengco 2001 (Rhizaria), ''Tetrahymena thermophila'' Nanney & McCoy 1976 (Alveolata), ''Thalassiosira pseudonana'' Cleve 1873 (Stramenopiles), and ''Arabidopsis thaliana'' (Linnaeus) Heynhold, 1842 (Archaeplastida), but not ''Homo sapiens'' Linnaeus 1758 (Opisthokonta), ''Dictyostelium discoideum'' Raper 1935 (Amoebozoa) or ''Euglena gracilis'' K ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plants+HC+SAR Megagroup
Diaphoretickes () is a major group of eukaryotic organisms, with over 400,000 species. The majority of the earth's biomass that carries out photosynthesis belongs to Diaphoretickes. Diaphoretickes includes: * Archaeplastida (comprising red algae, glaucophytes, and green algae & land plants) * Cryptista * Haptista * Hemimastigophora * SAR supergroup (consisting of stramenopiles+alveolates+Rhizaria) * Telonemia Where Chromista is used as a taxon, its member groups all fall within Diaphoretickes. In 2012 Diaphoretickes received the following phylogenetic definition: :"The most inclusive clade containing ''Bigelowiella natans'' Moestrup & Sengco 2001 (Rhizaria), ''Tetrahymena thermophila'' Nanney & McCoy 1976 (Alveolata), ''Thalassiosira pseudonana'' Cleve 1873 (Stramenopiles), and ''Arabidopsis thaliana'' (Linnaeus) Heynhold, 1842 (Archaeplastida), but not ''Homo sapiens'' Linnaeus 1758 (Opisthokonta), ''Dictyostelium discoideum'' Raper 1935 (Amoebozoa) or ''Euglena gracilis'' K ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diaphoretickes
Diaphoretickes () is a major group of eukaryotic organisms, with over 400,000 species. The majority of the earth's biomass that carries out photosynthesis belongs to Diaphoretickes. Diaphoretickes includes: * Archaeplastida (comprising red algae, glaucophytes, and green algae & land plants) * Cryptista * Haptista * Hemimastigophora * SAR supergroup (consisting of stramenopiles+alveolates+Rhizaria) * Telonemia Where Chromista is used as a taxon, its member groups all fall within Diaphoretickes. In 2012 Diaphoretickes received the following phylogenetic definition: :"The most inclusive clade containing ''Bigelowiella natans'' Moestrup & Sengco 2001 (Rhizaria), ''Tetrahymena thermophila'' Nanney & McCoy 1976 (Alveolata), ''Thalassiosira pseudonana'' Cleve 1873 (Stramenopiles), and ''Arabidopsis thaliana'' (Linnaeus) Heynhold, 1842 (Archaeplastida), but not ''Homo sapiens'' Linnaeus 1758 (Opisthokonta), ''Dictyostelium discoideum'' Raper 1935 (Amoebozoa) or ''Euglena gracilis'' K ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Cavalier-Smith
Thomas (Tom) Cavalier-Smith, FRS, FRSC, NERC Professorial Fellow (21 October 1942 – 19 March 2021), was a professor of evolutionary biology in the Department of Zoology, at the University of Oxford. His research has led to discovery of a number of unicellular organisms (protists) and advocated for a variety of major taxonomic groups, such as the Chromista, Chromalveolata, Opisthokonta, Rhizaria, and Excavata. He was known for his systems of classification of all organisms. Life and career Cavalier-Smith was born on 21 October 1942 in London. His parents were Mary Maude (née Bratt) and Alan Hailes Spencer Cavalier Smith. He was educated at Norwich School, Gonville and Caius College, Cambridge (MA) and King's College London (PhD). He was under the supervision of Sir John Randall for his PhD thesis between 1964 and 1967; his thesis was entitled "''Organelle Development in'' Chlamydomonas reinhardii". From 1967 to 1969, Cavalier-Smith was a guest investigato ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cavalier-Smith
Thomas (Tom) Cavalier-Smith, FRS, FRSC, NERC Professorial Fellow (21 October 1942 – 19 March 2021), was a professor of evolutionary biology in the Department of Zoology, at the University of Oxford. His research has led to discovery of a number of unicellular organisms (protists) and advocated for a variety of major taxonomic groups, such as the Chromista, Chromalveolata, Opisthokonta, Rhizaria, and Excavata. He was known for his systems of classification of all organisms. Life and career Cavalier-Smith was born on 21 October 1942 in London. His parents were Mary Maude (née Bratt) and Alan Hailes Spencer Cavalier Smith. He was educated at Norwich School, Gonville and Caius College, Cambridge (MA) and King's College London (PhD). He was under the supervision of Sir John Randall for his PhD thesis between 1964 and 1967; his thesis was entitled "''Organelle Development in'' Chlamydomonas reinhardii". From 1967 to 1969, Cavalier-Smith was a guest investigato ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discoba
Excavata is a major supergroup of unicellular organisms belonging to the domain Eukaryota. It was first suggested by Simpson and Patterson in 1999 and introduced by Thomas Cavalier-Smith in 2002 as a formal taxon. It contains a variety of free-living and symbiotic forms, and also includes some important parasites of humans, including '' Giardia'' and ''Trichomonas''. Excavates were formerly considered to be included in the now obsolete Protista kingdom. They are classified based on their flagellar structures, and they are considered to be the most basal flagellate lineage. Phylogenomic analyses split the members of Excavata into three different and not all closely related groups: Discobids, Metamonads and Malawimonads. Except for Euglenozoa, they are all non-photosynthetic. Characteristics Most excavates are unicellular, heterotrophic flagellates. Only the Euglenozoa are photosynthetic. In some (particularly anaerobic intestinal parasites), the mitochondria have been gre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scotokaryotes
The Scotokaryotes (Cavalier-Smith) is a proposed basal Neokaryote clade as sister of the Diaphoretickes. Basal Scotokaryote groupings are the Metamonads, the Malawimonas and the Podiata. In this phylogeny the Discoba are sometimes seen as paraphyletic and basal Eukaryotes. An alternative to the Unikont–Bikont division was suggested by Derelle ''et al.'' in 2015, where they proposed the acronyms Opimoda–Diphoda respectively, as substitutes to the older terms. The name Opimoda is formed from the letters (shown in capitals) of OPIsthokonta and 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 classi .... In this phylogeny Discoba belongs to the Diphoda clade. Taxonomy A proposed cladogram is See also * Diphoda References {{Taxonbar, from=Q21399998 Eukaryote unranke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cabozoa
In the classification of eukaryotes (living organisms with a cell nucleus), Cabozoa was a taxon proposed by Cavalier-Smith. It was a putative clade comprising the Rhizaria and Excavata. More recent research tends to place the Rhizaria with the Alveolata and heterokonts instead of the Excavata, however. See also *Corticata Corticata ("one with a cortex"), in the classification of eukaryotes (living organisms with a cell nucleus), is a clade suggested by Thomas Cavalier-Smith to encompass the eukaryote supergroups of the following two groups: * Plantae, or Archaepl ... References Obsolete eukaryote taxa Bikont unranked clades {{Bikont-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeplastida
The Archaeplastida (or kingdom Plantae ''sensu lato'' "in a broad sense"; pronounced /ɑːrkɪ'plastɪdə/) are a major group of eukaryotes, comprising the photoautotrophic red algae (Rhodophyta), green algae, land plants, and the minor group glaucophytes. It also includes the non-photosynthetic lineage Rhodelphidia, a predatorial (eukaryotrophic) flagellate that is sister to the Rhodophyta, and probably the microscopic picozoans. The Archaeplastida have chloroplasts that are surrounded by two membranes, suggesting that they were acquired directly through a single endosymbiosis event by feeding on a cyanobacterium. All other groups which have chloroplasts, besides the amoeboid genus ''Paulinella'', have chloroplasts surrounded by three or four membranes, suggesting they were acquired secondarily from red or green algae. Unlike red and green algae, glaucophytes have never been involved in secondary endosymbiosis events. The cells of the Archaeplastida typically lack centriol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Excavata
Excavata is a major supergroup of unicellular organisms belonging to the domain Eukaryota. It was first suggested by Simpson and Patterson in 1999 and introduced by Thomas Cavalier-Smith in 2002 as a formal taxon. It contains a variety of free-living and symbiotic forms, and also includes some important parasites of humans, including ''Giardia'' and ''Trichomonas''. Excavates were formerly considered to be included in the now obsolete Protista kingdom. They are classified based on their flagellar structures, and they are considered to be the most basal flagellate lineage. Phylogenomic analyses split the members of Excavata into three different and not all closely related groups: Discobids, Metamonads and Malawimonads. Except for Euglenozoa, they are all non-photosynthetic. Characteristics Most excavates are unicellular, heterotrophic flagellates. Only the Euglenozoa are photosynthetic. In some (particularly anaerobic intestinal parasites), the mitochondria have been greatly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromalveolata
Chromalveolata was a eukaryote supergroup present in a major classification of 2005, then regarded as one of the six major groups within the eukaryotes. It was a refinement of the kingdom Chromista, first proposed by Thomas Cavalier-Smith in 1981. Chromalveolata was proposed to represent the organisms descended from a single secondary endosymbiosis involving a red alga and a bikont. The plastids in these organisms are those that contain chlorophyll c. However, the monophyly of the Chromalveolata has been rejected. Thus, two papers published in 2008 have phylogenetic trees in which the chromalveolates are split up, and recent studies continue to support this view. Groups and classification Historically, many chromalveolates were considered plants, because of their cell walls, photosynthetic ability, and in some cases their morphological resemblance to the land plants (Embryophyta). However, when the five-kingdom system (proposed in 1969) took prevalence over the animal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
