Asgard_archaea | TriviaQuestions.online

⭐ Core Definition: Asgard archaea

Asgard archaea (previously known as superphylum "Asgard" or phylum "Asgardarchaeota") are a kingdom belonging to the domain Archaea that contain eukaryotic signature proteins.

After including the kingdom category into ICNP, the only validly published names of this group are kingdom Promethearchaeati and phylum Promethearchaeota. All formerly proposed "phyla" would be de-ranked to classes in this framework. It appears that the eukaryotes, the domain that contains the animals, plants, fungi and protists, emerged within the Promethearchaeati, in a branch containing the "Heimdallarchaeia" [de; es]. This supports the two-domain system of classification over the three-domain system.

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👉 Asgard archaea in the context of Eukaryote

The eukaryotes (/juːˈkærioʊts, -əts/) are the domain of Eukaryota or Eukarya, organisms whose cells have a membrane-bound nucleus. All animals, plants, fungi, seaweeds, and many unicellular organisms are eukaryotes. They constitute a major group of life forms alongside the two groups of prokaryotes: the Bacteria and the Archaea. Eukaryotes represent a small minority of the number of organisms, but given their generally much larger size, their collective global biomass is much larger than that of prokaryotes.

The eukaryotes emerged within the archaeal phylum Promethearchaeota. Ignoring mitochondrial DNA (which is bacterial rather than archaeal), this would imply only two domains of life, Bacteria and Archaea, with eukaryotes incorporated among the Archaea. Eukaryotes first emerged during the Paleoproterozoic, likely as flagellated cells. The leading evolutionary theory is they were created by symbiogenesis between an anaerobic Promethearchaeota archaeon and an aerobic proteobacterium, which formed the mitochondria. A second episode of symbiogenesis with a cyanobacterium created the plants, with chloroplasts.

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⭐ Core Definition: Asgard archaea
👉 Asgard archaea in the context of Eukaryote
Asgard archaea in the context of Endosymbiosis

Asgard archaea in the context of Endosymbiosis

An endosymbiont or endobiont is an organism that lives within the body or cells of another organism. Typically, the two organisms are in a mutualistic relationship. Examples are nitrogen-fixing bacteria (called rhizobia), which live in the root nodules of legumes, single-cell algae inside reef-building corals, and bacterial endosymbionts that provide essential nutrients to insects.

Endosymbiosis played key roles in the development of eukaryotes and plants. Roughly 2.3 billion years ago an archaeon (likely within the Asgard superphylum) absorbed an alphaproteobacterium through phagocytosis, that eventually became the mitochondria that provide energy to almost all living eukaryotic cells. Approximately 1 billion years ago, some of those cells absorbed cyanobacteria that eventually became chloroplasts, organelles that produce energy from sunlight. Approximately 100 million years ago, a lineage of amoeba in the genus Paulinella independently engulfed a cyanobacterium that evolved to be functionally synonymous with traditional chloroplasts, called chromatophores.

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Asgard archaea in the context of "Eukaryote"

⭐ In the context of Eukaryotes, the Asgard archaea, particularly the Promethearchaeota, are considered to be…

⭐ Core Definition: Asgard archaea

👉 Asgard archaea in the context of Eukaryote

Asgard archaea in the context of Endosymbiosis