A unique group of microorganisms that are called bacteria (Archaeobacteria) but are genetically and metabolically different from all other known bacteria. They appear to be living fossils, the survivors of an ancient group of organisms that bridged the gap in evolution between bacteria and multicellular organisms (eukaryotes).

Is a group of recently discovered organisms that resemble bacteria. However, these organisms are biochemically and genetically very different from bacteria. Some species of the domain Archaea live in [..]

One of two prokaryotic domains, the other being the Bacteria.

Microorganisms thought by some to have been the ancestors of the modern Eukaryota. Archaea surviving in today's world inhabit unlikely and difficult places. This group includes the thermophiles, [..]

organisms that resemble bacteria but also display characteristics found in multicellular organisms. They were discovered in 1977 and tend, like so many humans of that era, to favor extreme environments.

One of the three primary divisions of life. Archaea consist of unicellular organisms with prokaryotic cells. © 2005 by W. H. Freeman and Company. All rights reserved. Pierce, B. Genetics: A co [..]

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 ar [..]

One of the three domains of life. These are species that do not have nuclei and thus were originally grouped with bacteria

One of the three domains of life, archaea encompass any unicellular microorganisms that are genetically distinct from bacteria and eukarya, including organisms that inhabit extreme environments.

[noun] (plural of archaeon) One of three domains of life on Earth (the other two being Bacteria and Eukaryota), consisting of single-celled organisms that are prokaryotes (lacking membrane-bound organelles), yet phylogenetically and biochemically are as distinct from the Bacterial domain as they are from Eukaryotes.

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 sim [..]

One of the three domains of Life (the others being Bacteria and Eukarya), formerly called ArchaeBacteria under the taxon Bacteria, but now considered separate and distinct. They are characterized by: [..]

One of the three domains of life (the others being BACTERIA and Eukarya), formerly called Archaebacteria under the taxon Bacteria, but now considered separate and distinct. They are characterized by: [..]

("R-K-ah"): microscopic, single-celled organisms that along with bacteria make up the group "prokarya". Prokarya do not have nuclei. They are thought to be more clo [..]

are microbes that often resemble bacteria in size and shape but contain genes and metabolic pathways that are more similar to those of eukaryotes. They are, however, genetically distinct from both Bacteria and Eukarya, the other two domains of life on Earth. Archaea are found in a broad range of habitats, some very extreme, and are numerous in the [..]

Is a group of recently discovered organisms that resemble bacteria. However, these organisms are biochemically and genetically very different from bacteria. Some species of the domain Archaea live in the most extreme environments found on the Earth.

A unique group of microorganisms. They are called bacteria (Archaeobacteria) but they are genetically and metabolically different from all other known bacteria. They appear to be living fossils, the survivors of an ancient group of organisms that bridged the gap in evolution between bacteria and the eukaryotes (multicellular organisms). The name Ar [..]

One of the three domains of life. Archaea are unicellular and have a combination of characteristics unlike those of the other two domains.

Single-celled organisms lacking nuclei, formerly called archaebacteria, but now known to differ fundamentally from bacteria. # A taxonomic domain . #

(singular: archaeon) a group of tiny organisms often living in extreme environments, such as ocean vents and salt lakes.

micro-organisms that belong to a major division of life, as different from bacteria as humans are.