why are organisms placed into the domain of eukarya
Domain (biology) In biological taxonomy, a domain (Latin: regio[1]), also superkingdom or empire,[2] is the highest taxonomic rank of organisms in the three-domain system of taxonomy designed by Carl Woese, an American microbiologist and biophysicist. According to the Woese system, introduced in 1990, the tree of life consists of three domains: Archaea, Bacteria, and Eukarya.[1] The first two are all prokaryotic microorganisms, or single-celled organisms whose cells have no nucleus. All life that has a nucleus and membrane-bound organelles, and multicellular organisms, is included in the Eukarya. Stefan Luketa in 2012 proposed a five "dominion" system, adding two more to the above.[3]
Life Since its primordial beginnings, life on Earth has changed its environment on a geologic time scale. To survive in most ecosystems, life must often adapt to a wide range of conditions. Some microorganisms, called extremophiles, thrive in physically or geochemically extreme environments that are detrimental to most other life on Earth. Aristotle was the first person to classify organisms. Later, Carl Linnaeus introduced his system of binomial nomenclature for the classification of species. Eventually new groups and categories of life were discovered, such as cells and microorganisms, forcing dramatic revisions of the structure of relationships between living organisms. The cell is considered the structural and functional unit of life.[8] There are two kinds of cells, prokaryotic and eukaryotic, both of which consist of cytoplasm enclosed within a membrane and contain many biomolecules such as proteins and nucleic acids. Cells reproduce through a process of cell division, in which the parent cell divides into two or more daughter cells.