Biological Classification

Key Stage 4

Meaning

Classification is sorting living organisms into groups based on their similarities.

About Classification

Before the discovery of DNA classification was purely based on the appearance and behaviour of organisms.

Carl Linnaeus developed a system of classification based on the similar characteristics of organisms. Organisms were put into groups and sub-groups:

• Kingdom - The largest group. Examples include animals and plants.
• Phylum - The second largest group. Examples include chordata (animals with a backbone) and Arthropoda (animals with jointed legs and segmented bodies).
• Class - Examples include mammals (humans, neanderthals, chimpanzees, bonobos, gorillas, baboons, lemurs, dolphins, whales, cows, badgers) and birds (crows, ostriches).
• Order - Examples include primates (humans, neanderthals, chimpanzees, bonobos, gorillas, baboons, lemurs) and cetacea (dolphins and whales).
• Family - Examples include hominidae (humans, neanderthals, chimpanzees, bonobos and gorillas) and Cercopithecidae (baboons).
• Genus - Examples include Homo (humans and neanderthals) and Pan (chimpanzees and bonobos).
• Species - Sapien is the name for the human species.

Developments in genetics have further added to this system with three Domains above the Kingdoms:

• Archae - Primitive forms of bacteria.
• Bacteria
• Eukaryota - All eukaryotic organisms.