Biological Classification:-

Biological classification of Plants and Animals was first proposed by Aristotle on the basis of simple morphological characters.Linnaeus later classified all living organisms into two kingdoms:- Plantae and Animalia. R.H.whittaker proposed an elaborate five kingdom classification:- Monera, Protista, Fungi, Plantae and Animalia. The main criteria of the five kingdom classification were 1) Cell structure, 2) Body organization, 3) mode of nutrition, 4) Reproduction and 5) Phylogenetic relationships.

In the five-kingdom classification, bacteria are included in kingdom Monera. Bacteria are cosmopolitan in distribution. bacteria may be autotrophic or heterotrophic in their mode of nutrition.

Kingdom, Protista includes all single-celled Eukaryotes such as:- Chrysophytes, Dinoflagellates, Euglenoids, Slime-moulds, and Protozoans. Protista have defined Nucleus and other membrane-bound organelles. They reproduce asexually and sexually. 

 

Members of kingdom Fungi show a great Diversity in structure and habitat. Most fungi are saprophytic in their mode of nutrition. They show asexual and sexual reproduction.

 Ex:- Phycomycetes, Ascomycetes, Basidiomycetes, and Deuteromycetes as the four classes under this kingdom.

The Plantae includes all eukaryotic Chlorophyll-containing organisms. Algae, Bryophytes, pteridophytes, Gymnosperms, and Angiosperms are included in this group 

The heterotrophic eukaryotic, multicellular organisms lacking a cell wall are included in the kingdom Animalia. The mode of nutrition of these organisms is Holozoic. The reproduce mostly by the sexual mode.

Some Acellular organisms like viruses and viroids as well as the lichens are not included in the five-kingdom system of classification