Biological Classification – Kingdom Concept

There are two kingdom classification concepts proposed by Carolus Linnaeus and R.H. Whittaker respectively.

Two kingdom classification:

·         Carolus Linnaeus proposed the two kingdom classification and is known as the Father of Taxonomy.

·         Linnaeus classified organisms as Plantae (Plants - autotrophs, have cell wall, do not move) & Animalia (Animals - heterotrophs, have no cell wall, can move).

·         Later Linnaeus found that the two kingdom classification was not sufficient because in that

Ø  Both Prokaryotes & Eukaryotes were grouped together.

Ø  Heterotrophs & Autotrophs were together.

Ø  There was no difference between unicellular and multi cellular Organisms.

Ø  Simple organisms were placed along with higher organisms.

Five kingdom classification:

·         Proposed by R.H. Whittaker (1969).

·         The kingdoms defined by him were named Monera, Protista, Fungi, Plantae and Animalia.

Main criteria for classification:

·         Based on the complexity of cell structure, organisms are classified as prokaryotes/ Eukaryotes.

·         Based on the Body organization, organisms are classified as Unicellular/ Multicellular.

·         Based on the mode of nutrition, organisms are classified as autotrophic / heterotrophic /

·         holozoic/Parasitic/Symbiotic.

·         Based on Life style (Producers / Consumers / Decomposers)