5. Do eukaryotic cells have restriction endonucleases? Justify your answer.
No, eukaryotic cells do not possess restriction enzymes. All the restriction endonucleases have been developed and isolated from different strains of bacteria. The bacteria possess these restriction endonucleases as a defence mechanism to restrict the growth of viruses. Their own DNA remain safe from these enzymes because it is methylated. The eukaryotic cell has RNA interference as a defence mechanism against foreign DNA. Thus, eukaryotic cells do not have restriction endonucleases.