1 Both mitochondria and prokaryotic cells contain their own DNA. 2 Neither of the two have true nuclei, but they do have a space in which their DNA is enclosed. 3 Mitochondria and prokaryotic cells have similar transcriptional machinery, which means that they have the same process of making RNA from DNA. 4 Mitochondria contain their own genome, and the formation of their genome in most organisms is circular similar to prokaryotes.