Domain System Biology
According to this system the tree of life consists of three domains.
Domain system biology. In biology a domain refers to the largest of all groups in the classification of life. In biological taxonomy a domain d ə ˈ m eɪ n or d oʊ ˈ m eɪ n latin. The three domain system developed by carl woese in 1990 is a system for classifying biological organisms.
Archaea bacteria and eukarya. Regio also superkingdom realm or empire is the highest taxonomic rank of organisms in the three domain system of taxonomy devised by carl woese et al. There are currently 3 agreed groups at this level the archaea domain bacteria domain and eukarya domain.
Comparing rrna structure is especially useful.