On the Basis of Organisms' Classification
Whittaker's (1969) five kingdom system of organisms' classification, which is worldwide accepted, categorizes all organisms into five different kingdoms: the micro-organisms (except viruses, viroids etc.) are grouped in three of them. The bacteria and cyanobacteria are monerans; microalgae, protozoans and slime moulds are protistans, and; the microfungi are mycopbytans. The categorization is as follows:


