Five Kingdom System of Classification

Source:  Five Kingdom System of Classification    Tag:  kingdom protista classification
Five Kingdom System of Classification

Robert Whittaker 1967 introduced five kingdom classification system on the basis of the cellular organization i.e., prokaryotic, unicellular eukaryotic and Multicellular eukaryotic.
The principal modes of nutrition i.e. photosynthesis, absorption and ingestion
Although Lynn Margulies and Karlene shwaiz modified Whittaker five kingdom classification system in 1988 on the basis of cellular organization mode of nutrition, cytology, genetics and organelle symbiotic origin but the kingdom were five and same as proposed by Whittaker.

  • 1.       Kingdom Monera.
It includes the prokaryotic organisms in which the genetic material is not enclosed in the nuclear membrane. These are unicellular, although some types form chains, clusters or colonies of cells. Most are are interophic but some perform photosynthesis because they have chlorophyll in their cytoplasm e.g. photosynthetic and cyano bacteria (blue green algae).
Archeo bacteria (extremophiles i.e. like extreme environmental conditions) and rubacteria (true bacteria) and cyano bacteria included in kingdom Monera.

  • 2.       Kingdom Protista:
It includes eukaryotic unicellular and simple Multicellular organisms. There are three main types of protests. Algae are unicellular, colonial or sometimes simple Multicellular. They resemble plant cells because they have chlorophyll in chloroplast but they have cell wall of cellular simple Multicellular means that they cannot have Multicellular sex organs and do not form embryos during their life cycles. Protozoans resemble animals whose cells lack chlorophyll and cell walls. Some protests are like fungi.

  • 3.       Kingdom Fungi:
There eukaryotic Multicellular organisms. They are heterotrophy and take their food by absorption. Most fungi are decomposers. They live on organic material, secrete digestive enzymes and absorb small organic molecules formed by the digestion by enzymes. For example: mushrooms rust, smui molds.

  • 4.       Kingdom Plantae:
(i)                   It includes eukaryotic Multicellular autotropls i.e. They are capable of preparing their own food by photosynthesis because of the presence of chlorophyll in the chloroplast.
(ii)                 They have cell wall composed of cellulose.
(iii)                Ther have Multicellular sex organs and form embryos during their life cycles.
(iv)               Mosses, Ferns, Angiosperms and gymnosperm are included in Kingdom Plantae.

  • 5.       Kingdom Animalia:
(i)                   It includes eukaryotic Multicellular consumers.
(ii)                 Animals live mostly by ingesting food and digesting it within specialized cavities.
(iii)                They lack cell wall.
(iv)               They show movements.