Biological classification

• binomial system - uses the genus name + the species name to avoid confusion when naming organisms
• classification - the process of placing living things into groups
• Hierarchy - group within larger groups which don’t overlap
• Classifying living things

  • it is for our convenience
  • to make the study of living things more manageable
  • to make it easier to identify organisms
  • to help us see the relationships between species
• Modern Classification Hierarchy

  current system of classification uses 8 taxonomic levels :

  1. Domain
  2. Kingdom
  3. Phylum
  4. Class
  5. Order
  6. Family
  7. Genus
  8. Species
• • Domain - the highest taxonomic rank

  3 domains : Archea, Eubacteria + Eukaryotae
• • Kingdom - traditionally 5 main kingdoms : Plantae, Animalia, Fungi + Protoctista are all eukaryotic which possess a nucleus
  • ->all those who do not possess a nucleus are grouped into Kingdom Prokaryotae
• • Phylum - a major subdivision of the kingdom - contains all the groups of organisms that have same body plan e.g. possession of a backbone
• • Class - a group of organisms that all possess the same general traits w.g. same number of legs
• Order - a subdivision of the class using additional information about the organisms e.g. class animal is divided into meat-eating animals (order Carnivora) + vegetation-eating animals (order Herbivora)
• • Family - a group of closely related genera e.g. within the order Carnivora we might recognise the ‘dog’ and ‘cat’ family
• Species - the basic unit of classification - all members of a species show some variations, but all are essentially the same