Although both types of cells have a plasma/cell membrane, ribosomes, cytoplasm and genetic material there are many important differences. Many of the differences are related to their genetic material. Firstly, prokaryotes have 'naked' DNA, compared to DNA that is associated with proteins in eukaryotes. Furthermore, prokaryotic DNA is arranged into a circular chromosome, while eukaryotes organise their DNA into linear chromosomes. Eukaryotes house their DNA in a nucleus, while prokaryotic DNA is inside the cytoplasm as prokaryotes do not have nuclei. Finally, prokaryotes do not have introns and exons in their DNA, while eukaryotes do.Other differences include organelles like ribosomes. The ribosomes in prokaryotes are 70S, while in eukaryotes they are 80S. Prokaryotes also do not have membrane-bound organelles like those present within eukaryotes. When it comes time to divide, prokaryotes accomplish this through fission, but eukaryotes undergo mitosis. Additionally, prokaryotes are usually much smaller in size, at approximately 10 microns, while eukaryotes are approximately 100 microns. Finally, prokaryotes always have a cell wall, whereas in eukaryotic cells, only plants and fungi have a cell wall while mammalian cells do not.