The binomial system is used to classify organisms, with the first word being the genus name (capitalised) and the second word being the species name (lower case)
Woese suggested the three domain system
Archaea - Once thought to be primitive bacteria first found in extreme places
Bacteria - Contains true bacteria
Eukaryota- Containe a broad range of organisms, including fungi, plants, animals and protists
Evolutionary trees show how different species are related to eachother