Practice question

According to Woese, Fox, and colleagues 1990 proposal, cellular life partitions into three domains reflecting fundamental cellular organization: Bacteria comprising ester-linked lipid membranes, peptidoglycan walls, and single RNA polymerase; Archaea containing ether lipids, pseudomurein, distinct RNA polymerase multiplicity, and eukaryotic-like histones; and Eukarya defined by nucleus, spliceosomal introns, cytoskeleton, and mitochondria. Domains represent highest taxonomic rank above kingdom, each monophyletic. Subsequent genome projects confirmed domain separation through concatenated protein phylogenies, supporting division of formerly prokaryote-eukaryote dichotomy into tripartite scheme encompassing all cellular organisms excluding viruses.