1. Domain: The highest level of classification. There are three domains:
* Bacteria: Single-celled organisms without a nucleus.
* Archaea: Single-celled organisms without a nucleus, but with unique biochemistry.
* Eukarya: Organisms with cells that contain a nucleus.
2. Kingdom: Within each domain, organisms are further classified into kingdoms. Examples include:
* Animalia: Multicellular animals.
* Plantae: Multicellular plants.
* Fungi: Multicellular organisms that obtain nutrients by absorbing them from their surroundings.
* Protista: A diverse kingdom of mostly single-celled eukaryotes.
3. Phylum: A group of related classes within a kingdom.
4. Class: A group of related orders within a phylum.
5. Order: A group of related families within a class.
6. Family: A group of related genera within an order.
7. Genus: A group of closely related species.
8. Species: The most specific level of classification, defined as a group of organisms that can interbreed and produce fertile offspring.
Example:
* Domain: Eukarya
* Kingdom: Animalia
* Phylum: Chordata
* Class: Mammalia
* Order: Primates
* Family: Hominidae
* Genus: Homo
* Species: *Homo sapiens* (humans)
This system is known as the Linnaean taxonomy, named after the Swedish botanist Carl Linnaeus who developed it in the 18th century. It's a fundamental tool for understanding the diversity and relationships between living organisms.
