Bacteria, Archaea and Eukarya, based on fundamental cell differences and rRNA.
Carl Woese (1977) used 16S/18S rRNA sequences to identify Archaea as distinct from Bacteria. Archaea share more molecular machinery with Eukarya. Recent work puts eukaryotes within Archaea (two-domain tree).
Domain-level differences include membrane lipids, RNA polymerase and cell wall chemistry. Eukaryotes arose from an archaeal host that engulfed a bacterium.
Remember: domains sit above kingdoms.
Bacteria, Archaea and Eukarya, based on fundamental cell differences and rRNA.
Three Domains of Life is one of the 52 topics in Taxonomy & Biodiversity. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Taxonomic Hierarchy, Conservation Biology, Shared Derived Characters.
Methanogens are archaea; E. coli is a bacterium.
Three Domains of Life is a Beginner topic, so no earlier topic is required. Other Beginner topics in Taxonomy & Biodiversity that pair well with it include Taxonomy, Binomial Nomenclature, Taxonomic Hierarchy.
The closest topics to Three Domains of Life are Taxonomic Hierarchy, Conservation Biology, Shared Derived Characters, Cryptic Species. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Three Domains of Life. To practise the whole of Taxonomy & Biodiversity, use the Taxonomy & Biodiversity quiz.
Three Domains of Life: Bacteria, Archaea and Eukarya, based on fundamental cell differences and rRNA. Taxonomic Hierarchy: Domain, kingdom, phylum, class, order, family, genus and species form nested ranks. Read both side by side and note what each one explains.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Taxonomic Hierarchy and explain the difference aloud. Finally, take the Taxonomy & Biodiversity quiz and come back to this page for any question you miss.
Domain, kingdom, phylum, class, order, family, genus and species form nested ranks.
🗂️ Taxonomy & BiodiversityThe scientific study and protection of biodiversity.
🗂️ Taxonomy & BiodiversityNovel traits inherited from a recent common ancestor that define a clade.
🗂️ Taxonomy & BiodiversityDistinct species that look nearly identical and are separated only by molecular or behavioural evidence.
🗂️ Taxonomy & Biodiversity