The five kingdom classification that we are studying now is not the initial one. Linnaeus first came up with two kingdom classifications: Plantae and Animalia. He classifies based on movement and growth limit. In Plantae, he placed living organisms that are not able to move and have unlimited growth and in Animale, the living organisms are able to move but growth is limited.
But due to this classification so many doubts arose regarding the placing of certain species. The two-kingdom classification lasts for longer but not forever. It fails to differentiate eukaryotes, prokaryotes, photosynthetic, non-photosynthetic, unicellular, and multicellular. There are some living organisms that we can not keep under Plantae or Animalia.
At that time there was so much confusion even some scientists had discovered three kingdoms, four kingdoms, etc., but in all those five kingdoms classification is adopted by many people and even now we only study about that widely.
Five kingdom classification divides living organisms based on their mode of nutrition, cell structure, thallus organization, and reproduction which was done by Whittaker.
The five kingdom classification system was proposed by R.H. Whittaker in 1969. The system of arranging living organisms in groups or sets depending upon their likeness and variance is known as classification. By doing this we are able to study a wide variety of living organisms in an easy way. Whittaker classified living organisms in these five kingdoms based on the structure of cell, mode of nutrition, source of nutrition, body organization, reproduction, and interrelations.
Ernst Haeckel, Whittaker, Carl these biologists attempted for border classification but in these all we widely used and accepted the five kingdom classification.
Robert H Whittaker classified living organisms broadly into five kingdoms in 1969.
They are as follows:
Kingdoms are divided into subgroups at various levels for making our study and observation easy. This is the flowchart showing the hierarchy of classification.
Kingdom—> Phylum—>Class—> Order—> Family—> Genus—-> Species
Monerans have bacteria. Bacteria occur everywhere in nature, some are harmful and some are useful. Under the monera kingdom, prokaryotes are there which possess a cell wall. The cell wall is made up of polysaccharides. The mode of nutrition of monera can be autotrophic or heterotrophic. Some are photosynthetic and some or not. Monerans are unicellular which don’t have a well-defined nucleus and also lack organelles. Monera is further classified into archaebacteria and eubacteria.
Bacteria are classified into four types based on their shape and they are:
Examples of monerans are bacteria, cyanobacteria, and mycoplasma.
Protists are eukaryotic living organisms. They have cilia and flagella for mobility on their surface. Reproduction takes place in the form of cell fusion and zygote formation. Protists are heterotrophic and also autotrophic. Protists are further divided into
The father of the Five Kingdom Classification is Robert Whittaker, an American biologist. He proposed the five-kingdom system in 1969 to classify organisms based on their cell structure, mode of nutrition, and reproduction. This classification system was a significant advancement over the previous two-kingdom system and provided a more detailed and systematic approach to classifying life forms.
The Five Kingdom Classification system by Robert Whittaker divides life into five broad categories based on distinct characteristics. These are:
The main character in the context of the Five Kingdoms is Robert Whittaker, as he is the scientist who proposed the Five Kingdom Classification system. His work helped shift the scientific understanding of biodiversity and organism classification, influencing modern biology and taxonomy.
Five Kingdoms (Whittaker’s Classification):
Six Kingdom Classification: In the Six Kingdom Classification, Monera is divided into two kingdoms:
The Six Kingdoms classification was introduced as a refinement to Whittaker's Five Kingdom system, incorporating advances in molecular biology and genetic research that clarified the relationships between organisms.
