Practice question

Bacteria and Archaea collectively represent prokaryotic grade of organization characterized by absence of membrane-bound nucleus, 70S ribosomes, circular chromosome typically without histones, and binary fission. Both domains lack mitochondria, endoplasmic reticulum, and mitosis, though they differ fundamentally in membrane lipid chirality, cell wall chemistry, and RNA polymerases. The term prokaryote originally grouped them to contrast with eukaryotic complexity, emphasizing structural simplicity. Despite genomic divergence revealed by Woese, shared cellular architecture justifies collective reference as prokaryotes, including two distinct domains among three domains of life.