During DNA replication, DNA methylation: please explain answer  a. A and C b.  B. marks the strand not cut in mismatch repair c.  A and B d. A. marks the parental DNA strand e. C. marks the strand cut in mismatch repair

The experiment below is from a seminal set of experiments in the 1960s that illustrated the role of various repair pathways for DNA damage caused by UV radiation. In this experiment, the scientists isolated E coli strains that are mutant in the Rec A gene, the UvrA gene or both. They then irradiated cultures of each strain with increasing doses of UV light and measured the effect on cell viability. Answer the following questions about this data. A. Which DNA repair pathway and repair activity is inhibited by the Rec A mutant? B. Which DNA repair pathway and repair function is inhibited by UvrA mutant? C. Why is the UvrA/RecA double mutant so much more senitive to UV light than either mutant alone?

Can you explain it?

Which of the following DNA repair pathways repair DNA double strand breakage that only occur in diving cells?. Please select all correct answers. A. Nucleotide excision repair (NER) B. Mismatch repair (MMR) C. Double- strand break repair(DSBR) D.non- homologous end joining (NHEJ) E. Synthesis-dependent strand annealing(SDSA)