Question

Patient with Xerodermapigmentosum experience increased frequency of skin cancer. This isdue to a defect in the nucleotide excision repair (NER) pathway.This pathway involves the removal of UV damaged nucleotides withnucleases and the removed sequence is then filled in by DNApolymerase. Compare/contrast this process with DNAproofreading.

a) they are likely to occur in difference phases of the cellcycle
b) only one involves the breaking of phosphodiester bonds
c) if the nuclease activity is from DNA polymerase, one is likelyto involve 5' to 3' nuclease activity while the other involves the3' to 5' activity
d) one likely involves an exonuclease while the other anendonuclease