One of the three domains of life. Like Bacteria, they are all microorganisms and lack a nucleus.
One of the three domains of life (the others being BACTERIA and Eucarya), formerly called Archaebacteria under the taxon Bacteria, but now considered separate and distinct. They are characterized by: (1) the presence of characteristic tRNAs and ribosomal RNAs; (2) the absence of peptidoglycan cell walls; (3) the presence of ether-linked lipids built from branched-chain subunits; and (4) their occurrence in unusual habitats. While archaea resemble bacteria in morphology and genomic organization, they resemble eukarya in their method of genomic replication. The domain contains at least three kingdoms: CRENARCHAEOTA; EURYARCHAEOTA; and KORARCHAEOTA.
A prokaryotic form of life that forms a domain in the tree of life. There are three domains: bacteria, archaea, and eukarya. Bacteria are also prokaryotic organisms. Eukaryotes include animals, plants, fungi, and protozoan and have very different cell structures, bigger and with internal membrane bound structures (organelles). While bacteria and archaea look similar in structure, they have very different metabolic and genetic activity. One defining physiological characteristic of archaea is their ability to live in extreme environments. They are often called extremophiles and unlike bacteria and eukarya depend on either high salt, high or low temperature, high pressure, or high or low pH.
Organisms making up one of the three branches on the phylogenetic tree of life. Their cells do not contain a defined nucleus and they are genetically and biochemically distinct from the Bacteria. See Eukaryotes and Bacteria.
(Greek, archein= to begin), also called the Archaebacteria The kingdom (or "domain") of single-celled organisms that live under extreme environmental conditions and have distinctive biochemical features.
A kingdom of "old bacteria," now commonly found in extreme environments like hot springs.
an early prokaryotic microbe, distinct from bacteria, that first appeared nearly 4 billion years ago
archaeon (sing.) one of the three current major domains of life, the others being the eukaryotes and the eubacteria. These bacteria-like organisms, all single-celled and lacking nuclei, are often, but not always, are found in extreme environments.
An evolutionarily distinct group (domain) of prokaryotes consisting of the methanogens, most extreme halophiles and hyperthermophiles, and Thermoplasma.
ar-KEE-a One of the three domains of life. Archaea are unicellular and have a combination of characteristics unlike those of the other two domains. 430
One of three domains of life, along with the Bacteria and the Eucarya. The archaea are prokaryotic organisms which were shown to be a distinct group from the bacteria by molecular phylogeny using 16S ribosomal RNA. The archaeal domain includes many extremophilic organisms.
Class of prokaryotes that constitutes one of the three distinct evolutionary lineages of modern-day organisms; also called archaebacteria and archaeans. These prokaryotes are in some respects more similar to eukaryotes than to the so-called true bacteria ( eubacteria). ( Figure 1-5)
One of the two main groups of prokaryotes, mostly found in extreme environments.
prokaryotic organisms evolutionarily distinct from bacteria; their gene expression pattern (transcription and translation) is more like the eukaryotic pattern.
Proposed, but not widely accepted, sixth taxonomic kingdom that would include the archaebacteria.
Bacteria (single-celled organisms) that live at high temperatures such as the high temperatures found within hydrothermal vent structures.
Unicellular microorganisms that constitute one of the three domains of life: bacteria, archaea, and eukaryotes. Like bacteria, archaea have no true nucleus; however, archaea are considered to be more closely related than bacteria to eukaryotes, organisms with a true nucleus.
(pronounced "are-kay"). One-celled, microscopic organisms without a nucleus. Half to two-thirds of their genes are unlike anything else on earth.; they are ancient, first appearing 3 to 4 billion years ago, and tend to favor extreme environments such as hydrothermal vents.
micro-organisms that belong to a major division of life, as different from bacteria as humans are.
Primitive, bacteria-like organism living in high-temperature environments [LCOTE
unicellular microorganisms that are members of Domain Archaea, one of the three trunks of the Tree of Life
Archaea (; from Greek αÏχαία, "ancient ones"; singular Archaeum, Archaean, or Archaeon), also called Archaebacteria , is a major division of living organisms. Although there is still uncertainty in the exact phylogeny of the groups, Archaea, Eukaryota and Bacteria are the fundamental classifications in what is called the three-domain system. Like bacteria, Archaea are single-celled organisms lacking nuclei and are therefore prokaryotes, classified as Monera in the alternative six-kingdom taxonomy.
