Biological Classification

SYNOPSIS

• Different classification systems proposed by scientists:
  
  
  

  Classification System	Description
  Two Kingdom Classification	Linnaeus (1758) divided all organisms into two kingdoms—Plantae and Animalia
  Three Kingdom Classification	Haeckel (1866) created a new kingdom Protista having only unicellular eukaryotes.
  Four Kingdom Classification	Copeland (1956) placed prokaryotes under a separate kingdom named Monera.
  Five Kingdom Classification	R.H. Whittaker (1969) classified organisms into five kingdoms—Monera, Protista, Plantae, Fungi and Animalia.
  Six Kingdom Classification	Carl Woese proposed the three domain system—Archae (Archaebacteria), Bacteria (Eubacteria), Eukarya (Plantae, Animalia, Protista, Fungi).

• Classification of Kingdom Protista:
• Classification of Kingdom Fungi:
  
  
  
  
  
• Classification of Kingdom Monera:
  
  
  
  

• Viruses are non-cellular organisms characterised by an inert crystalline structure outside the living cell.

• Viroids are infectious RNA particles which lack a protein coat. 

• Prions are infectious proteinaceous agents which lack genetic material.

• Lichens are the symbiotic association between an alga (phycobiont) and a fungus (mycobiont).

Different classification systems proposed by scientists: