Domain Kingdom Biology
The three domain system developed by carl woese in 1990 is a system for classifying biological organisms.
Domain kingdom biology. Before woese s discovery of archaea as distinct from bacteria in 1977 scientists believed there were only two types of life. On the other hand the kingdom is a major category of living organisms below the domain level. The key difference between kingdom and domain is that the kingdom is one of the five major groups of living organisms while the domain is one of the three taxonomic categories of living organisms above the kingdom level.
Thus domain is a category above the kingdom level. Accordingly there are three domains namely bacteria archaea and eukarya. In biological taxonomy a domain d ə ˈ m eɪ n or d oʊ ˈ m eɪ n latin.
Regnum plural regna is the second highest taxonomic rank just below domain kingdoms are divided into smaller groups called phyla traditionally some textbooks from the united states and canada used a system of six kingdoms animalia plantae fungi protista archaea archaebacteria and bacteria eubacteria while textbooks in countries like great britain india. There are five kingdoms namely monera protista. According to this system the tree of life consists of three domains.