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Estrutura celular. Ver artigos principais: Célula e Célula eucariótica. Esquema de uma célula típica eucarionte animal: (1) Nucléolo com cromossomos, (2) Núcleo, (3) Ribossoma, (4) Vesícula, (5) Retículo endoplasmático rugoso, (6) Complexo de Golgi, (7) Microtúbulos, (8) Retículo endoplasmático liso, (9) Mitocôndria, (10) Vacúolo ...
The eukaryotes (/ j uː ˈ k ær i oʊ t s,-ə t s / yoo-KARR-ee-ohts, -əts) constitute the domain of Eukarya or Eukaryota, organisms whose cells have a membrane-bound nucleus. All animals, plants, fungi, and many unicellular organisms are eukaryotes.
- Context
- Symbiogenesis
- Last Eukaryotic Common Ancestor
- Scenarios
- Diversification: Crown Eukaryotes
- External Links
Life arose on Earth once it had cooled enough for oceans to form. The last universal common ancestor (LUCA) was an organism which had ribosomes and the genetic code; it lived some 4 billion years ago. It gave rise to two main branches of prokaryotic life, the bacteria and the archaea. From among these small-celled, rapidly-dividing ancestors arose ...
According to the theory of symbiogenesis (also known as the endosymbiotic theory) championed by Lynn Margulis, a member of the archaea gained a bacterial cell as a component. The archaeal cell was a member of the Asgard group. The bacterium was one of the Alphaproteobacteria, which had the ability to use oxygen in its respiration. This enabled it –...
The last eukaryotic common ancestor (LECA) is the hypothetical last common ancestor of all living eukaryotes, around 2 billion years ago, and was most likely a biological population. It is believed to have been a protist with a nucleus, at least one centriole and cilium, facultatively aerobic mitochondria, sex (meiosis and syngamy), a dormant cyst ...
Biologists have proposed multiple scenarios for the creation of the eukaryotes. While there is broad agreement that the LECA must have had a nucleus, mitochondria, and internal membranes, the order in which these were acquired has been disputed. In the syntrophic model, the first eukaryotic common ancestor (FECA, around 2.2 gya) gained mitochondria...
In turn, the LECA gave rise to the eukaryotes' crown group, containing the ancestors of animals, fungi, plants, and a diverse range of single-celled organisms with the new capabilities and complexity of the eukaryotic cell. Single cells without cell walls are fragile and have a low probability of being fossilised. If fossilised, they have few featu...
Attraction and sex among our microbial Last Eukaryotic Common Ancestors, The Atlantic, November 11, 2020
O domínio taxonômico Eukariota, Eukaria, Eukarya, Eukaryota, também referido como eucariotas ou eucariontes inclui todos os seres vivos com células eucarióticas, ou seja, com um núcleo celular cercado por uma membrana e com várias organelas.
En biología y taxonomía, Eukaryota o Eukarya (del griego: εὖ eu —‘bueno’, ‘bien’, 'verdadero'— y κάρυον karyon —‘nuez’, ‘carozo’, ‘núcleo’—) es el dominio (o imperio) que incluye los organismos formados por células con núcleo verdadero.
Gli eucarioti (Eukaryota, dal greco εὖ eu «vero» e κάρυον káryon «nucleo») sono, con i procarioti, uno dei due domini della classificazione tassonomica degli esseri viventi.
En resumen, Eukaryota incluye a los organismos pluricelulares repartidos en los reinos: Animalia, Plantae y Fungi, y también se encuentran los organismo unicelulares (microscópicos), entre los que están microsporidios, protozoos (ameboides, flagelados, ciliados), levaduras, algunos hongos y mohos.
