What are the levels of classification listed in order from general to specific?
Biologists traditionally begin with Domain; Kingdom; Phylum; Order; Class; Family; Genus; species; and subspecies.
The first categorical level--called a taxonomic level--is the broadest. That means it includes the MOST organisms. By organisms we are including only cell-based organisms, so viruses, viroids and prions are not included.
As one goes further down these levels, there are fewer organisms present in that level. It may help to think of an upside-down triangle, where the Domain (Eukarya, Archaea or Bacteria) is at the top or widest level. Once the genus and species is identified-for example, Homo neanderthalis _then very few organisms, if any, still live on Earth for that genus and species.