What are the principal taxa used in classifying eukaryotes?
What are the principal taxa used in classifying eukaryotes?
Answer
Eukaryotes are classified using a hierarchical system of taxa that includes several principal categories. The classification can vary slightly depending on the specific framework used, but the following ranks are commonly recognized in the classification of eukaryotic organisms:
Principal Taxa for Classifying Eukaryotes
- Domain: Eukarya
- This is the highest taxonomic rank for eukaryotic organisms, distinguishing them from prokaryotes (Bacteria and Archaea).
- Supergroup:
- Recent classifications often include supergroups to better reflect evolutionary relationships among eukaryotes. For example, the supergroups include:
- SAR (Stramenopiles, Alveolata, Rhizaria)
- Excavata
- Archaeplastida
- Opisthokonta
- Recent classifications often include supergroups to better reflect evolutionary relationships among eukaryotes. For example, the supergroups include:
- Kingdom:
- Traditionally, eukaryotes have been divided into four main kingdoms:
- Animalia (animals)
- Plantae (plants)
- Fungi (fungi)
- Protista (a diverse group of mostly unicellular organisms)
- Traditionally, eukaryotes have been divided into four main kingdoms:
- Phylum (or Division in Botany):
- This rank groups organisms based on major body plans or structural features. For example:
- In Animalia: Chordata (vertebrates)
- In Plantae: Angiosperms (flowering plants)
- This rank groups organisms based on major body plans or structural features. For example:
- Class:
- A more specific grouping within a phylum. For instance:
- In Chordata: Mammalia (mammals)
- In Angiosperms: Dicotyledonae (dicots)
- A more specific grouping within a phylum. For instance:
- Order:
- Groups related families together. For example:
- In Mammalia: Carnivora (carnivorous mammals)
- Groups related families together. For example:
- Family:
- A group of related genera. For example:
- In Carnivora: Canidae (dogs and their relatives)
- A group of related genera. For example:
- Genus:
- A group of closely related species. For instance:
- Canis (the genus that includes dogs and wolves)
- A group of closely related species. For instance:
- Species:
- The most specific level of classification, representing individuals that can interbreed. For example:
- Canis lupus (gray wolf)
- The most specific level of classification, representing individuals that can interbreed. For example:
Summary of Taxonomic Hierarchy
Rank | Description |
---|---|
Domain | Eukarya |
Supergroup | Major clades reflecting evolutionary relationships |
Kingdom | Major divisions within Eukarya |
Phylum | Groups based on body plans |
Class | More specific groupings within phyla |
Order | Related families grouped together |
Family | Related genera |
Genus | Closely related species |
Species | Most specific rank; capable of interbreeding |