how si the five kingdom classification advantageous over two kingdom classification????.. reply soooonnnn!!!!!
In two kingdom classification organisms are classified on the basis of presence or absence of cell wall in Plants and Animals. so, organisms which have features of both plants and animals are difficult to place. Demerits of two kingdom classification are as follows:
- There is no clear-cut distinction in the lower forms of life, into plants and animals e.g. Euglena is a unicellular organism having certain features of animals and certain features of plants. It has a flagellum which is used for locomotion and food capturing. However, it has chloroplasts like plant cells. It also lacks a cell wall.
- The eukaryotes have been put together with the prokaryotes .
- Fungi have been put under Plantae despite the fact that they lack, cellulose, cell wall, chlorophyll. They are saprophytic or parasitic in their mode of nutrition unlike the plants.
- The two kingdom system takes unicellular and multicellular organisms together. The bacteria were also considered as plants under this system of classification.
so, five kingdom classification was proposed by Whittaker to minimize the demerits of two kingdom classification. So, Whittaker used following criteria for classification"
- cell organization
- Body organization
- Mode of nutrition
- Life style(whether the organism is producer,composer or decomposer)
Five kingdoms of Whittaker's classification are as follows:
Monera -Organisms without membrane bound organelles.
Protista -Unicellular Organisms which have Nuclei which don't fit anywhere else
Fungi -Multicellular Organisms with Cell walls, with Nuclei and which absorb their nutrition.
Plantae -Multicellular Organisms with Cell Walls, with Nuclei and which make their own nutrition
Animalia -Multicellular Organisms with No Cell Walls