Life is classified in many levels from less specific to more specific:
Domain (bacteria, archaea, eukaryotes)
Kingdom
Phylum
Class
Order
Family
Genus
Species
The domains 'contains' the most number of organisms, species contain the least number of organisms.
Answer:
Species
Explanation:
The highest taxonomic category is domain followed by kingdom, phylum, class, order, family, genus and species. Among this, being the highest category, domain includes maximum number of organisms. On the other hand, being the lowest taxonomic category, species would include least number of organisms.
Example: Domain “eukarya” includes all the eukaryotic organisms while species "sapiens" includes only present day human beings.
