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Life Extension Organizations
Life, also known as biota, refers to matter that has biological processes, such as signaling and self-sustaining processes. It is defined descriptively by the capacity for homeostasis, organisation, metabolism, growth, adaptation, response to stimuli, and reproduction. All life over time eventually reaches a state of death, and none is immortal. Many philosophical definitions of living systems have been proposed, such as self-organizing systems. Viruses in particular make definition difficult as they replicate only in host cells. Life exists all over the Earth in air, water, and soil, with many ecosystems forming the biosphere. Some of these are harsh environments occupied only by extremophiles. Life has been studied since ancient times, with theories such as Empedocles's materialism asserting that it was composed of four eternal elements, and Aristotle's hylomorphism asserting that living things have souls and embody both form and matter. Life originated at le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archean
The Archean ( , also spelled Archaean or Archæan), in older sources sometimes called the Archaeozoic, is the second of the four geologic eons of Earth's history of Earth, history, preceded by the Hadean Eon and followed by the Proterozoic and the Phanerozoic. The Archean represents the time period from (million years ago). The Late Heavy Bombardment is hypothesized to overlap with the beginning of the Archean. The Huronian glaciation occurred at the end of the eon. The Earth during the Archean was mostly a ocean world, water world: there was continental crust, but much of it was under an ocean deeper than today's oceans. Except for some rare Relict (geology), relict crystals, today's oldest continental crust dates back to the Archean. Much of the geological detail of the Archean has been destroyed by subsequent activity. The Earth's atmosphere was also vastly different in atmospheric chemistry, composition from today's: the prebiotic atmosphere was a reducing atmosphere rich in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemimastigophora
Hemimastigophora is a group of unicellular, single-celled eukaryotic organisms including the Spironematellidae, first identified in 1988, and the Paramastigidae. 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 kingdom (biology), kingdoms. It may be 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 (biology), tree of life was unclear, but the authors suggested that the structure of its Pellicle (biology), pellicle and cell nucleus indicated a close relationship with Euglenozoa. For 30 years after the description of the group, no genetic informati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Realm (virology)
In virology, realm is the highest taxonomic rank established for viruses by the International Committee on Taxonomy of Viruses (ICTV), which oversees virus taxonomy. Six virus realms are recognized and united by specific Conserved sequence, highly conserved traits: * ''Adnaviria'', which contains archaeal filamentous viruses with A-form double-stranded (ds) DNA genomes encoding a unique alpha-helical major capsid protein; * ''Duplodnaviria'', which contains all dsDNA viruses that encode the HK97-fold major capsid protein; * ''Monodnaviria'', which contains all single-stranded DNA (ssDNA) viruses that encode a HUH-tag, HUH superfamily endonuclease and their descendants; * ''Riboviria'', which contains all RNA viruses that encode RNA-dependent RNA polymerase and all viruses that encode reverse transcriptase; * ''Ribozyviria'', which contains hepatitis delta-like viruses with circular, negative-sense ssRNA genomes; * and ''Varidnaviria'', which contains all dsDNA viruses that en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virus
A virus is a submicroscopic infectious agent that replicates only inside the living Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting tobacco plants and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898, more than 16,000 of the millions of List of virus species, virus species have been described in detail. The study of viruses is known as virology, a subspeciality of microbiology. When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent viral particles, or ''virions'', consisting of (i) genetic material, i.e., long ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-cellular Life
Non-cellular life, also known as acellular life, is life that exists without a cellular structure for at least part of its life cycle. Historically, most definitions of life postulated that an organism must be composed of one or more cells, but, for some, this is no longer considered necessary, and modern criteria allow for forms of life based on other structural arrangements. Nucleic acid-containing infectious agents Viruses Researchers initially described viruses as "poisons" or "toxins", then as "infectious proteins"; but they possess genetic material, a defined structure, and the ability to spontaneously assemble from their constituent parts. This has spurred extensive debate as to whether they should be regarded as fundamentally biotic or abiotic—as very small biological organisms or as very large biochemical molecules. Without their hosts, they are not able to perform any of the functions of life—such as metabolism, growth, or reproduction. Since the 195 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parakaryon Myojinensis
''Parakaryon myojinensis'', also known as the Myojin parakaryote, is a highly unusual species of single-celled organism known only from a single specimen, described in 2012. It has features of both prokaryotes and eukaryotes but is apparently distinct from either group, making it unique among organisms discovered thus far. It is the sole species in the genus ''Parakaryon''. Etymology The generic name ''Parakaryon'' comes from Greek παρά (''pará'', "beside", "beyond", "near") and κάρυον (''káryon'', "nut", "kernel", "nucleus"), and reflects its distinction from eukaryotes and prokaryotes. The specific name ''myojinensis'' reflects the locality where the only sample was collected: from the bristle of a scale worm collected from hydrothermal vents at Myōjin Knoll (明神海丘, ), about deep in the Pacific Ocean, near Aogashima island, southeast of the Japanese archipelago. The authors explain the full binomial as "next to (eu)karyote from Myojin". Structure '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incertae Sedis
or is a term used for a taxonomy (biology), taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty at specific taxonomic levels is indicated by (of uncertain family), (of uncertain suborder), (of uncertain order) and similar terms. Examples * The fossil plant ''Paradinandra, Paradinandra suecica'' could not be assigned to any family, but was placed ''incertae sedis'' within the order Ericales when described in 2001. * The fossil ''Gluteus minimus (fossil), Gluteus minimus'', described in 1975, could not be assigned to any known animal phylum. The genus is therefore ''incertae sedis'' within the kingdom Animalia. * While it was unclear to which order the New World vultures (family Cathartidae) should be assigned, they were placed in Aves ''incertae sedis''. It was later agreed to place them in a separate order, Cathartiformes. * Boc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parakaryon
''Parakaryon myojinensis'', also known as the Myojin parakaryote, is a highly unusual species of single-celled organism known only from a single specimen, described in 2012. It has features of both prokaryotes and eukaryotes but is apparently distinct from either group, making it unique among organisms discovered thus far. It is the sole species in the genus ''Parakaryon''. Etymology The generic name ''Parakaryon'' comes from Greek παρά (''pará'', "beside", "beyond", "near") and κάρυον (''káryon'', "nut", "kernel", "nucleus"), and reflects its distinction from eukaryotes and prokaryotes. The specific name ''myojinensis'' reflects the locality where the only sample was collected: from the bristle of a scale worm collected from hydrothermal vents at Myōjin Knoll (明神海丘, ), about deep in the Pacific Ocean, near Aogashima island, southeast of the Japanese archipelago. The authors explain the full binomial as "next to (eu)karyote from Myojin". Structure '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TSAR
Tsar (; also spelled ''czar'', ''tzar'', or ''csar''; ; ; sr-Cyrl-Latn, цар, car) is a title historically used by Slavic monarchs. The term is derived from the Latin word '' caesar'', which was intended to mean ''emperor'' in the European medieval sense of the term—a ruler with the same rank as a Roman emperor, holding it by the approval of another emperor or a supreme ecclesiastical official—but was usually considered by Western Europeans to be equivalent to "king". Tsar and its variants were the official titles in the First Bulgarian Empire (681–1018), Second Bulgarian Empire (1185–1396), the Kingdom of Bulgaria (1908–1946), the Serbian Empire (1346–1371), and the Tsardom of Russia (1547–1721). The first ruler to adopt the title ''tsar'' was Simeon I of Bulgaria. Simeon II, the last tsar of Bulgaria, is the last person to have held this title. Meaning in Slavic languages The title tsar is derived from the Latin title for the Roman emperors, ''c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haptista
Haptista is a proposed group of protists made up of centrohelids and haptophytes. Phylogenomic studies indicate that Haptista, together with ''Ancoracysta twista'', forms a sister clade to the SAR supergroup#Internal phylogeny, TSAR Supergroup (biology), supergroup, but it may also be sister to the Cryptista (+Archaeplastida). It is thus one of the earliest diverging Diaphoretickes. Taxonomy Based on studies done by Cavalier-Smith, Chao & Lewis 2015 and Ruggiero et al. 2015. * Subphylum Centroheliozoa Cushman & Jarvis 1929 sensu Durrschmidt & Patterson 1987 [Heliozoa Haeckel 1862 stat. n. Margulis 1974 em. Cavalier-Smith 2003] ** Class Centrohelea Kuhn 1926 stat. n. Cavalier-Smith 1993 [Centroplastiales; Centrohelina Hartmann 1913; Centroplasthelida Febvre-Chevalier 1984] * Subphylum Haptophyte, Haptophytina Cavalier-Smith 2015 (Haptophyta Hibberd 1976 sensu Ruggerio et al. 2015) ** Clade Rappemonada Kim et al. 2011 *** Class Rappephyceae Cavalier-Smith 2015 ** Clade Haptomonada ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptista
Cryptista is a clade of alga-like eukaryotes. It is most likely related to Archaeplastida which includes plants and many algae, within the larger group Diaphoretickes. Other characteristic features of cryptophyte mtDNAs include large syntenic clusters resembling α-proteobacterial operons that encode bacteria-like rRNAs, tRNAs, and ribosomal protein genes. Additionally, they are an evolutionarily significant lineage found in mostly marine, glacial and freshwater environments. Although it has sometimes placed along with Haptista in the group Hacrobia, within the kingdom Chromista, most recent studies have found that Hacrobia is not a clade. For example, in 2016, a broad phylogenomic study found that cryptists fall within the group Archaeplastida, while haptophytes are closely related to the SAR supergroup. Taxonomy Based on studies done by Cavalier-Smith, Chao & Lewis 2015 * Corbihelia ** Clade Endohelia Cavalier-Smith 2015 *** Clade Endohelea Cavalier-Smith 2012 * Cla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant
Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with cyanobacteria to produce sugars from carbon dioxide and water, using the green pigment chlorophyll. Exceptions are parasitic plants that have lost the genes for chlorophyll and photosynthesis, and obtain their energy from other plants or fungi. Most plants are multicellular organism, multicellular, except for some green algae. Historically, as in Aristotle's biology, the plant kingdom encompassed all living things that were not animals, and included algae and fungi. Definitions have narrowed since then; current definitions exclude fungi and some of the algae. By the definition used in this article, plants form the clade Viridiplantae (green plants), which consists of the green algae and the embryophytes or land plants (hornworts, liverworts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
