Why classify?
There are millions of organisms on Earth, so scientists use classification to arrange them into groups based on shared characteristics. Classification makes it easier to study, name and identify living things. Organisms with many features in common are placed in the same group.
Kingdoms of life
The largest groups are called kingdoms. Living things are commonly sorted into five kingdoms:
| Monera | bacteria, single-celled |
| Protista | amoeba, mostly single-celled |
| Fungi | mushrooms, moulds, yeast |
| Plantae | trees, flowers, ferns |
| Animalia | insects, fish, mammals |
Key idea
Classification moves from large, general groups to small, specific ones: Kingdom → group → species. The smallest group, the species, contains organisms that are most alike and can reproduce together.
Naming a species
Every species is given a two-word scientific name using binomial nomenclature. The first word is the genus and the second names the species, and the name is written in italics.
Example
The scientific name of the tiger is Panthera tigris. Panthera is the genus (also shared with lions) and tigris names the species.
Remember
- Classification groups organisms by shared features.
- Five kingdoms: Monera, Protista, Fungi, Plantae, Animalia.
- Binomial nomenclature gives each species a two-word Latin name.