Question 3
Explain the basis for grouping organisms into five kingdoms.
R.H. Whittaker proposed the five kingdom classifications of living organisms which include Kingdom Monera, Protista, Fungi, Plantae and Animalia.
The basis of grouping organisms into five kingdoms is as follows:
Cell Structure: There are two broad categories of cell structure:– Eukaryotic and Prokaryotic. All prokaryotes come under the kingdom Monera and rest all are kept in other kingdoms.
Number of cells: It divides into unicellular and multicellular. Unicellular eukaryotes are kept in the kingdom Protista, while multicellular eukaryotes are kept in other kingdoms.
Mode and source of nutrition and Cell wall: Organisms are divided into autotrophs and heterotrophs based on the mode of nutrition. Heterotrophic organisms in which cell wall is present are taken under the kingdom Fungi. Autotrophic organisms in which cell wall is present are taken in the kingdom Plantae. Organisms in which cell wall is absent are taken in the kingdom Animalia.