Friday 5 January 2018

Explain the basis for grouping organisms into five kingdoms.

Answer : Robert .H. Whittaker in 1959 proposed a five kingdom classification of living organisms on the basis of Linnaeus’ system of classification encorporating cell structure, mode and source of nutrition and body organisation as main features. The five kingdoms proposed by Whittaker are Monera, Protista, Fungi, Plantae, and Animalia

The basis for grouping organisms into five kingdoms is as follows :
(i) On the basis of the presence or absence of membrane-bound organelles, all living organisms  are divided into two broad categories of eukaryotes and prokaryotes. This division lead to the formation of kingdom Monera, which includes all prokaryotes.
(ii) Then, eukaryotes are divided as unicellular and multicellular, on the basis of cellularity. Unicellular eukaryotes form kingdom Protista, and multicellular eukaryotes form kingdom Fungi, Plantae, and Animalia.
(iii) Animals are then separated on the basis of the absence of a cell wall.
(iv) Since fungi and plants both contain a cell wall, they are separated into different kingdoms on the basis of their modes of nutrition. Fungi have saprophytic mode of nutrition, whereas plants have autotrophic mode of nutrition. This results in the formation of the five kingdoms

Check for Complete Solved Exercise | Chapter 7. Diversity in Living Organisms | CBSE Class 9th Science