What type of repair would be used to fix a mutation that arises during replication and that escapes detection by polymerase proofreading mechanisms? What is the most likely reason that this mutation escaped correction during proofreading?

According to the double-strand break model, does gene conversionnecessarily involve DNA mismatch repair? Explain.

Restriction endonucleases are bacterial enzymes that cleave duplex (double-stranded) DNA at specific nucleotide sequences. The mode of replication of the animal virus SV40 has been investigated by using restriction endonucleases that cleave SV40 DNA into a number of unique segments. Like most viruses, SV40 DNA is circular. The map positions of the 11 fragments produced by a pair of restriction endonucleases are shown on the next page. Immediately following a 5 or 10 minute pulse of radioactively labeled thymidine, labeled SV40 molecules that have completed replication during the pulse are isolated. These newly replicated DNA molecules are digested by the restriction endonucleases and the resulting fragments are analyzed for the relative amounts of pulse label they contain. The results are in the table below. Assume that at the time the label was added there was a random population of replicating SV40 DNA molecules in all possible stages of synthesis. From the information given below,…

In the Meselson–Stahl experiment, which of the three modes of replication could be ruled out after one round of replication? after two rounds?