sentences:  At damaged sites in the genome, both prokaryotic and eukaryotic cells utilize a number of postreplication repair (PRR) mechanisms to complete DNA replication.Chemically modified bases can be bypassed by either error-prone or error-free translesion polymerases, or through genetic exchange with the sister chromatid.The replication of DNA with a broken sugar-phosphate backbone is most likely facilitated by the homologous recombination proteins that confer resistance to ionizing radiation.