To show how organisms are related, scientists classify them into levels of organization. Scientists who classify organisms and name them are called taxonomists.
Taxonomists classify and name organisms so that we can tell them apart from each other. Even though a starfish, catfish, and a crayfish all share the word fish, they are actually very different types of species.
The levels of classification used to identify organisms are categorized from broad to specific. The most specific level of classification contains only one organism, while the broad level of classification includes many organisms that are distant relatives.
The full classification for a blue whale:
Organisms that have complex cells that have a nucleus are categorized in the domain "Eukarya".
Eukaryotic organisms that get food from other organisms and cannot produce their own food are categorized in the kingdom "Animalia".
Animals that have backbones are classified in the phylum "Chordata".
Animals with backbones that have hair and produce milk for their young are classified in the class "Mammalia".
Marine mammals such as porpoises, whales, and dolphins are classified in the order "Cetacea".
Many whales that use baleen hair to collect krill for food are categorized in the family "Balaenopteridae".
Eight species of baleen whales are classified in the genus "Balaenoptera".
The blue whale is classified with the species name "musculus".