The Five Kingdom Classification

The Five Kingdom Classification

The five kingdom classification was proposed by R.H. Whittaker in 1969. Five kingdoms were formed on the basis of characteristics such as cell structure, mode of nutrition, source of nutrition and body organization.

1. Kingdom Monera - Bacteria

All prokaryotes belong to the Kingdom Monera, which do not posses true nucleus. Cells of prokaryotes do not have a nuclear membrane and any membrane bound organelles. Most of the bacteria are heterotrophic, but some are autotrophs. Bacteria and Blue green algae are examples for monera.

2. Kingdom Protista:

The Kingdom Protista includes unicellular and a few simple multicellular eukaryotes.

There are two main groups of protists. The plant like protists are photosynthetic and are commonly called algae. Algae include unicellular and multicellular types. Animals like protists are often called protozoans. They include amoeba and paramecium.

3. Kingdom Fungi:

Fungi are eukaryotic, and mostly are multicellular. They secrete enzymes to digest the food and absorb the food after digested by the enzymes. Fungi saprophytes as decomposers (decay –causing organisms) or as parasites. Kingdom Fungi includes molds, mildews, mushrooms and yeast.

4. Kingdom Plantae:

Planatae (plants) are multicellular eukaryotes that carry out photosynthesis. Reserve food materials are starch and lipids in the form of oil or fat. Plant cells have cell wall and specialized functions, such as photosynthesis, transport of materials and support. Kingdom Plantae includes ferns, cone bearing plants and flowering plants.

5. Kingdom Animalia:

Animalia (animals) are multicellular, eukaryotic and heterotrophic animals. Cells have no cell wall. Most members of the animal kingdom can move from place to place. Eg. Invertebrates like sponges, hydra, flatworms round worms, insects, snails, starfishes. Vertebrates like Fish, amphibians, reptiles, birds, and mammals including human beings belong to the kingdom Animalia.

IMPORTANT CHARACTERISTICS OF FIVE KINGDOMS

Merits of five Kingdom Classification

* This system of classification is more scientific and natural.

* This system of classification clearly indicates the cellular organization, mode of nutrition, and characters for early evolution of life.

* It is the most accepted system of modern classification as the different groups of organisms are placed phylogenetically.

* It indicates gradual evolution of complex organisms from simpler one.

Demerits of five Kingdom Classifications

* In this system of classification of viruses have not been given a proper place.

* Multicellular organisms have originated several times from protists.

* This type of classification has drawn back with reference to the lower forms of life.

* Some organisms included under protista are not eukaryotic.