The five-kingdom classification proposed by R.H.Whittaker consisted of Monera, Protista, Fungi, Plantae, and Animalia. This classification was based on differentiating features like structure, body organization, mode of nutrition, phylogenetic relationships, and reproduction. Photautotrophs like blue-green algae were included in the kingdom Plantae, but in this classification has brought together all the prokaryotic organisms under the kingdom Monera, which also includes the heterotrophic bacteria like E. coli or pathogenic bacterias, and chemotrophic bacterias like Nitrosomonas, suplur-utilizing bacteria etc.