Prokaryotes do have their genomic DNA concentrated and localized to a small area within cell. so its not accurate to say that they do not have a nucleus.
Prokaryotes are single-celled organisms belonging to the domains Bacteria and Archaea. Prokaryotic cells are much smaller than eukaryotic cells, have no nucleus, and lack organelles. All prokaryotic cells are encased by a cell wall. Many also have a capsule or slime layer made of polysaccharide.
