Classification

Classification groups organisms by comparing their similarities and differences:

Traditional (Linnaean) classification system

• The traditional classification system, devised by Carl Linnaeus, categorises organisms based on their structure and characteristics.
• He created 7 different groups - Kingdom, Phylum, Class, Order, Family, Genus, Species.

3-domain system

Carl Woese proposed the 3 domain system. This classifies organisms based on chemical analysis.

The 3 domains are:

• Archaea - primitive bacteria.
• Bacteria - true bacteria.
• Eukaryota - organisms possessing complex sub-cellular structures (protists, fungi, plants and animals).