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Metakaryota
The superkingdom Metakaryota was defined by Thomas Cavalier-Smith as advanced eukaryotes resulting from the endosymbiosis of a proteobacterium, giving rise to the 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 use ..., by an archezoan eukaryote. However, with the collapse of the Archezoa hypothesis (that amitochondriate eukaryotes were basal), this grouping was abandoned in later schemes. References Obsolete eukaryote taxa {{biology-stub ... [...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 making up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryota
Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacteria and Archaea (both prokaryotes) make up the other two domains. The eukaryotes are usually now regarded as having emerged in the Archaea or as a sister of the Asgard archaea. This implies that there are only two domains of life, Bacteria and Archaea, with eukaryotes incorporated among archaea. Eukaryotes represent a small minority of the number of organisms, but, due to their generally much larger size, their collective global biomass is estimated to be about equal to that of prokaryotes. Eukaryotes emerged approximately 2.3–1.8 billion years ago, during the Proterozoic eon, likely as Flagellated cell, flagellated phagotrophs. Their name comes from the Greek language, Greek wikt:εὖ, εὖ (''eu'', "well" or "good") and wikt:Π... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Martin Embley
(Thomas) Martin Embley is a professor at Newcastle University who has made contributions to our understanding of the origin of eukaryotes and the evolution of organelles such as mitochondria, One or more of the preceding sentences incorporates text from the royalsociety.org website where: mitosomes and hydrogenosomes, that are found in parasitic protists. In May 2021, Embley was appointed as a Fellow of the Royal Society. Education Embley was educated at Newcastle University, where he was awarded a PhD PHD or PhD may refer to: * Doctor of Philosophy (PhD), an academic qualification Entertainment * '' PhD: Phantasy Degree'', a Korean comic series * ''Piled Higher and Deeper'', a web comic * Ph.D. (band), a 1980s British group ** Ph.D. (Ph.D. albu ... on the biology of the bacterium '' Renibacterium salmoninarum'' in 1983. References {{DEFAULTSORT:Embley, Martin Fellows of the Royal Society Fellows of the Academy of Medical Sciences (United Kingdom) Members of the Eur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Sciences
Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditary information encoded in genes, which can be transmitted to future generations. Another major theme is evolution, which explains the unity and diversity of life. Energy processing is also important to life as it allows organisms to move, grow, and reproduce. Finally, all organisms are able to regulate their own internal environments. Biologists are able to study life at multiple levels of organization, from the molecular biology of a cell to the anatomy and physiology of plants and animals, and evolution of populations.Based on definition from: Hence, there are multiple subdisciplines within biology, each defined by the nature of their research questions and the tools that they use. Like other scientists, biologists use the scientific m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
