1)Aristotle: First tried o classify all organisms into plants and animals on a scientific basis.
2)Linnaeus: He classified all organisms into two kingdoms namely Kingdom Plantae and Kingdome Animalia. However, he did not distinguish prokaryotes from eukaryotes, unicellular from multicellular organisms, photosynthetic from non photosynthetic organisms. Yet, due to the introduction of Binomial nomenclature, Linnaeus is considered to be the ‘Father of taxonomy’.
3)Haeckel : He identified kingdom protista.
4)Copeland: Proposed a 4 system of classification-Monera, Protista, Metaphyta and Meta zoa.
5)R.H. Whittaker: He proposed 5 kingdom classification; Monera, Protista, Fungi, Plantae and Animalia.
6)Woose: He proposed 6 kingdom classification-Archaebacteria, Eubacteria, Protista, Fungi, Plantae and Animalia.