Which is a true difference between prokaryotes and eukaryotes? which is a true difference between prokaryotes and eukaryotes? prokaryotes are all gram positive, eukaryotes are all gram negative prokaryotes are all single celled, eukaryotes are all multicellular prokaryotes all have cell walls, no eukaryotes have cell walls prokaryotes comprise a non-monophyletic grouping, while eukaryotes are monophyletic all of the above are true statements?