The statement that is NOT a characteristic that prokaryotes and eukaryotes share is:
a) All cells have membrane-bound organelles and a nucleus.
This is incorrect because prokaryotes do not have membrane-bound organelles or a nucleus; they have a simpler cellular structure. Eukaryotes, on the other hand, do contain membrane-bound organelles and a nucleus. The other options (having cell membranes, ribosomes, and DNA/RNA) are characteristics shared by both prokaryotic and eukaryotic cells.