Carl Woese and collaborators identified two major branches of prokaryotic evolution. What was the basis for dividing prokaryotes into two domains?

The genetic characteristics such as ribosomal RNA sequences was the basis for dividing prokaryotes into two domains.

Explanation:

The six kingdom classification of living things include Animalia, Plantae, Fungi, Protista, Archaea (Archaebacteria), and Bacteria (Eubacteria). This classification is based on multicellularity, the presence or absence of nucleus, cell wall and membrane-bound organelles. Carl Richard Woese, an American microbiologist, and his colleagues grouped organisms into three domains - Bacteria, Archaea and Eukarya, based on the comparison of the sequences of small-subunit ribosomal RNA and differences in the cell membrane structures and in rRNA.

All prokaryotes are divided into domain Bacteria (cyanobacteria, proteobacteria, spirochetes, chlamydias, and gram-positive bacteria) and domain Archaea (euryarchaeotes, korarchaeotes, crenarchaeotes, and nanoarchaeotes) on the basis of genetic characteristics such as ribosomal RNA sequences. All eukaryotes are present in the domain Eukarya (animals, plants, fungi, and protists).

Prokaryotes are simple unicellular organisms that do not have a nucleus and membrane-bound organelles. Eukaryotes are complex multicellular organisms that have an organized nucleus and several membrane-bound organelles.