The three domains are: Bacteria, Archaea, and Eukarya. The three domain system was introduced by Carl Woese. The domain Archaea are prokaryotes, like the methanogens, and halophiles; this domain includes members with no nuclear membrane, a distinct biochemistry and RNA markers from bacteria. The domain bacteria consists of members like the cyanobacteria, the actinobacteria etc. They have a cell membrane made of glycerol diester lips and a bacterial rRNA but no nuclear membrane. The eukaryotes are the most developed with three kingdoms - fungi, animalia and plantae; they have membranes in their nucleus
