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Endamoebidae
The Archamoebae are a group of protists originally thought to have evolved before the acquisition of mitochondria by eukaryotes. They include genera that are internal parasites or commensals of animals (''Entamoeba'' and '' Endolimax''). A few species are human pathogens, causing diseases such as amoebic dysentery. The other genera of archamoebae live in freshwater habitats and are unusual among amoebae in possessing flagella. Most have a single nucleus and flagellum, but the giant amoeba '' Pelomyxa'' has many of each. Description Archamoebae are a diverse group of amoebae. Many have flagella for motility, while others do not. They grow in the absence of oxygen, though some can tolerate small amounts. Most described species of Archamoebae either lack mitochondria or are described to have reduced mitosomes. Habitat They thrive and live in soil, freshwater, and marine habitats. History The group Archamoebae was proposed by Thomas Cavalier-Smith in 1998 as part of the Archez ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mastigamoebidae
The Archamoebae are a group of protists originally thought to have evolved before the acquisition of mitochondria by eukaryotes. They include genera that are internal parasites or commensals of animals (''Entamoeba'' and '' Endolimax''). A few species are human pathogens, causing diseases such as amoebic dysentery. The other genera of archamoebae live in freshwater habitats and are unusual among amoebae in possessing flagella. Most have a single nucleus and flagellum, but the giant amoeba '' Pelomyxa'' has many of each. Description Archamoebae are a diverse group of amoebae. Many have flagella for motility, while others do not. They grow in the absence of oxygen, though some can tolerate small amounts. Most described species of Archamoebae either lack mitochondria or are described to have reduced mitosomes. Habitat They thrive and live in soil, freshwater, and marine habitats. History The group Archamoebae was proposed by Thomas Cavalier-Smith in 1998 as part of the Archez ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tricholimacidae
The Archamoebae are a group of protists originally thought to have evolved before the acquisition of mitochondria by eukaryotes. They include genera that are internal parasites or commensals of animals (''Entamoeba'' and '' Endolimax''). A few species are human pathogens, causing diseases such as amoebic dysentery. The other genera of archamoebae live in freshwater habitats and are unusual among amoebae in possessing flagella. Most have a single nucleus and flagellum, but the giant amoeba '' Pelomyxa'' has many of each. Description Archamoebae are a diverse group of amoebae. Many have flagella for motility, while others do not. They grow in the absence of oxygen, though some can tolerate small amounts. Most described species of Archamoebae either lack mitochondria or are described to have reduced mitosomes. Habitat They thrive and live in soil, freshwater, and marine habitats. History The group Archamoebae was proposed by Thomas Cavalier-Smith in 1998 as part of the Archez ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endamoebidae
The Archamoebae are a group of protists originally thought to have evolved before the acquisition of mitochondria by eukaryotes. They include genera that are internal parasites or commensals of animals (''Entamoeba'' and '' Endolimax''). A few species are human pathogens, causing diseases such as amoebic dysentery. The other genera of archamoebae live in freshwater habitats and are unusual among amoebae in possessing flagella. Most have a single nucleus and flagellum, but the giant amoeba '' Pelomyxa'' has many of each. Description Archamoebae are a diverse group of amoebae. Many have flagella for motility, while others do not. They grow in the absence of oxygen, though some can tolerate small amounts. Most described species of Archamoebae either lack mitochondria or are described to have reduced mitosomes. Habitat They thrive and live in soil, freshwater, and marine habitats. History The group Archamoebae was proposed by Thomas Cavalier-Smith in 1998 as part of the Archez ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelobiontida
The Archamoebae are a group of protists originally thought to have evolved before the acquisition of mitochondria by eukaryotes. They include genera that are internal parasites or commensals of animals (''Entamoeba'' and '' Endolimax''). A few species are human pathogens, causing diseases such as amoebic dysentery. The other genera of archamoebae live in freshwater habitats and are unusual among amoebae in possessing flagella. Most have a single nucleus and flagellum, but the giant amoeba '' Pelomyxa'' has many of each. Description Archamoebae are a diverse group of amoebae. Many have flagella for motility, while others do not. They grow in the absence of oxygen, though some can tolerate small amounts. Most described species of Archamoebae either lack mitochondria or are described to have reduced mitosomes. Habitat They thrive and live in soil, freshwater, and marine habitats. History The group Archamoebae was proposed by Thomas Cavalier-Smith in 1998 as part of the Archez ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelomyxidae
The Archamoebae are a group of protists originally thought to have evolved before the acquisition of mitochondria by eukaryotes. They include genera that are internal parasites or commensals of animals (''Entamoeba'' and '' Endolimax''). A few species are human pathogens, causing diseases such as amoebic dysentery. The other genera of archamoebae live in freshwater habitats and are unusual among amoebae in possessing flagella. Most have a single nucleus and flagellum, but the giant amoeba '' Pelomyxa'' has many of each. Description Archamoebae are a diverse group of amoebae. Many have flagella for motility, while others do not. They grow in the absence of oxygen, though some can tolerate small amounts. Most described species of Archamoebae either lack mitochondria or are described to have reduced mitosomes. Habitat They thrive and live in soil, freshwater, and marine habitats. History The group Archamoebae was proposed by Thomas Cavalier-Smith in 1998 as part of the Archez ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelomyxina
The Archamoebae are a group of protists originally thought to have evolved before the acquisition of mitochondria by eukaryotes. They include genera that are internal parasites or commensals of animals (''Entamoeba'' and '' Endolimax''). A few species are human pathogens, causing diseases such as amoebic dysentery. The other genera of archamoebae live in freshwater habitats and are unusual among amoebae in possessing flagella. Most have a single nucleus and flagellum, but the giant amoeba '' Pelomyxa'' has many of each. Description Archamoebae are a diverse group of amoebae. Many have flagella for motility, while others do not. They grow in the absence of oxygen, though some can tolerate small amounts. Most described species of Archamoebae either lack mitochondria or are described to have reduced mitosomes. Habitat They thrive and live in soil, freshwater, and marine habitats. History The group Archamoebae was proposed by Thomas Cavalier-Smith in 1998 as part of the Archez ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mastigamoebina
The Archamoebae are a group of protists originally thought to have evolved before the acquisition of mitochondria by eukaryotes. They include genera that are internal parasites or commensals of animals (''Entamoeba'' and '' Endolimax''). A few species are human pathogens, causing diseases such as amoebic dysentery. The other genera of archamoebae live in freshwater habitats and are unusual among amoebae in possessing flagella. Most have a single nucleus and flagellum, but the giant amoeba '' Pelomyxa'' has many of each. Description Archamoebae are a diverse group of amoebae. Many have flagella for motility, while others do not. They grow in the absence of oxygen, though some can tolerate small amounts. Most described species of Archamoebae either lack mitochondria or are described to have reduced mitosomes. Habitat They thrive and live in soil, freshwater, and marine habitats. History The group Archamoebae was proposed by Thomas Cavalier-Smith in 1998 as part of the Archez ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RRNA
Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosomal DNA (rDNA) and then bound to ribosomal proteins to form small and large ribosome subunits. rRNA is the physical and mechanical factor of the ribosome that forces transfer RNA (tRNA) and messenger RNA (mRNA) to process and translate the latter into proteins. Ribosomal RNA is the predominant form of RNA found in most cells; it makes up about 80% of cellular RNA despite never being translated into proteins itself. Ribosomes are composed of approximately 60% rRNA and 40% ribosomal proteins by mass. Structure Although the primary structure of rRNA sequences can vary across organisms, base-pairing within these sequences commonly forms stem-loop configurations. The length and position of these rRNA stem-loops allow them to create three- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitosomes
A mitosome is an organelle found in some unicellular eukaryotic organisms, like in members of the supergroup Excavata. The mitosome was found and named in 1999, and its function has not yet been well characterized. It was termed a ''crypton'' by one group, but that name is no longer in use. The mitosome has been detected only in anaerobic or microaerophilic organisms that do not have mitochondria. These organisms do not have the capability of gaining energy from oxidative phosphorylation, which is normally performed by mitochondria. The mitosome was first described in ''Entamoeba histolytica,'' an intestinal parasite of humans. Mitosomes have also been identified in several species of Microsporidia and in '' Giardia intestinalis''. Origin and function Mitosomes are almost certainly derived from mitochondria. Like mitochondria, they have a double membrane and most proteins are delivered to them by a targeting sequence of amino acids. The targeting sequence is similar to that used ... [...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 inves ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archezoa
Archezoa was a kingdom proposed in the 20th century by Thomas Cavalier-Smith (1942–2021), and was believed to encompass eukaryotes which did not have mitochondria (and are therefore ''amitochondriate'') or peroxisomes (e.g. '' Giardia''). The category was dropped after it was discovered that all the amitochondriates were descendants of eukaryotes with mitochondria that had lost them. History Origin This taxonomic category was proposed upon the discovery that some protists lacked mitochondria, which suggested to Cavalier-Smith that the initial ancestor of eukaryotes emerged prior to the endosymbiosis of mitochondria (cf. '' Giardia''). Eukaryotes that eventually acquired a bacterial endosymbiont that became the mitochondria were placed in a taxonomic group which Cavalier-Smith called the Metakaryota, whereas the Archezoa represented a paraphyletic group involving four phyla representing primitive eukaryotes which evolved prior to the acquisition of mitochondria. Organisms mak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entamoeba Histolytica
''Entamoeba histolytica'' is an anaerobic parasitic amoebozoan, part of the genus ''Entamoeba''. Predominantly infecting humans and other primates causing amoebiasis, ''E. histolytica'' is estimated to infect about 35-50 million people worldwide. ''E. histolytica'' infection is estimated to kill more than 55,000 people each year. Previously, it was thought that 10% of the world population was infected, but these figures predate the recognition that at least 90% of these infections were due to a second species, '' E. dispar''. Mammals such as dogs and cats can become infected transiently, but are not thought to contribute significantly to transmission. The word '' histolysis'' literally means disintegration and dissolution of organic tissues. Transmission The active ( trophozoite) stage exists only in the host and in fresh loose feces; cysts survive outside the host in water, in soils, and on foods, especially under moist conditions on the latter. The infection can occur whe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
