5 kingdom classification From Aristotle to Copland system of classification, a need of natural system of classification, based on ancestral relationship eas always left. Such classification was proposed by R. H. Whittaker in 1o69.it is one of the most widely accepted system. This system is based on the cool three criterias.
1. Complexity of cell structure- whether the cell is Prokaryktic or Eukaryotic.
2.complexity of body organization- whether it's unicellular and simple or multicellular and complex.
3.mode of nutrition- it maybe autotrophic or heteroteophic
Whittaker divided the organisms into the following five kingdoms. He placed all the prokaryotes in monera and most unicellular simple Eukaryotes in protista. He considered fungi, which acquire nutrition by absorption, sufficiently different from plants.
1.Kingdom monera( kingdom of prokaryotes) kingdom monera including all the Prokaryktic organisms ie cyanobactetia, Archaebacteria and Eubacteria. All monera are unicellular, they lack nucleic acids and other membranes bound organelles. Their DNA is with out histones protein and is found in the form of single chromosome. They reproduce by binary fission or may undergo genetic recombination. Moneras are the important decomposers and mineralisers in the biosphere.
2.kingdom protista ( kingdom of unicellular Eukaryotes)
There possess true nucleus and other Membrane bound organelles. Most of them possess flagella or cilia at some stage of their life cycle. Protista are extremely complex, their cell show even more diversity than is found among the cell of multicellular kingdom. They don't develop from an embryo as plants and animals do. Y
The kid include variety of life form ex. Algae resemble like plants ( diatoms) , protozoa resemble like animals (amoeba, paramecium) and euglenoids ( euglena) which have both plants and animals characters.
Protista are either autotrophic or holozoic which feed on other protists by injection..a few protists live on animals as parasites.
3.kingdom fungi( kingdom of multicellular decomposers)
This kingdom includes unicellular (yeast) multicellular(eg molds) and macroscopic ( eg mushroom) fungi. In multicellular fungi the cells join together to form a thin tubes called hyphae. Cell wall mostly made-up chitin.they lack chlorophyll so, they are either parasites or saprophytes.
4.kingdom plantae( kingdom of multicellular producers)
It includes multicellular autotrophic plants, characterized by presence of cellulosic cell wall. The main groups included are seaweed like green, red,and brown algae, all mosses, ferns, conifers and flowering plants. They have photosynthetic pigments chlorophyll and are only the organisms which have the capacity to synthesize complex organic compounds from CO2 and water using light energy trapped by the photosynthetic pigments. Thus they are the primary producers of a land and alone sea shores.
5.kingdom animalia ( multicellular consumers)
Into animals of vertebrate and invertebrates, are heteroteophic and obtain energy by injection of organic matter. They are derived from zygote, show organ -system organization, very few animals show cellular organization ( sponges) or tissue organization( hydra) . Animals show locomotion.
Although Whittaker's system is the most accepted classification it has certain demerits.for ex, both kingdom mk monera and protista include walled and wall less organisms, photosynthetic and nonphotosynthetic organisms, and unicellular and fillamentius or mycelial form.
All the best....
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