Biology - Diversity in Living Organisms



  • Biodiversity term is used to define the diversity of life forms.

  • Biodiversity is a word more often used to refer to the variety of life forms found in a particular geographic region.

  • Diversity of life forms of a geographic region provides stability in the respective region.

Base of Classification

  • Greek thinker Aristotle first classified animals based on their place of residence whether they lived on land, in water, or in the air.

  • Later, all the living organisms are identified and categorized on the basis of their body design in form and function.

  • The idea of evolution was first described by Charles Darwin in 1859 in his book namely – The Origin of Species.’

  • Charles Darwin first described this idea of evolution in 1859 in his book, ‘The Origin of Species.’

Hierarchy of Classification Groups

  • Some biologists, namely Ernst Haeckel (1894), Robert Whittaker (1959), and Carl Woese (1977) have attempted to classify all living organisms into broad categories and named them ‘Kingdoms.’

  • Whittaker categorized into five kingdoms namely −

    • Monera

    • Protista

    • Fungi

    • Plantae

    • Animalia

  • Further, these kingdoms have been classification by naming the sub-groups at various levels as −

  • Let’s discuss each kingdom in brief −


  • The organisms of Monera kingdom do not have a defined nucleus or organelles, neither do any of them show multi-cellular body designs.

Monera Kingdom
  • The examples of this monera kingdom are bacteria, anabaena, blue-green algae or cyanobacteria, and mycoplasma.


  • The organisms of Protista kingdom include many kinds of unicellular eukaryotic organisms.

  • The examples of Protista kingdom are algae, euglena, diatoms, and protozoans, etc.


  • The organisms of fungi kingdom are heterotrophic eukaryotic organisms.

  • The organisms of this kingdom use decaying organic material as their food and therefore, they are also known as saprophytes.


  • The organisms of this kingdom are multicellular eukaryotes with cell walls.

  • The organisms of plantae are autotrophs and they use chlorophyll for making their food (i.e. photosynthesis).

  • All plants are examples of plantae kingdom.


  • The organisms of Animalia kingdom are all organisms which are multicellular eukaryotes without cell walls.

  • Organisms of Animalia kingdom are heterotrophs.