Question

Question 6 1 pts You created a mutant form of DNA polymerase in which the 3'to 5'exonuclease (proofreading] function has been destroyed, although its polymerase activity is still fine. Which of the following properties do you expect the mutant polymerase to have? O It will polymerize in both the 5-to-3' direction and the 3-to-5' direction. O It will likely make a new strand of DNA (same length) slower than a normal polymerase. It will be more likely to generate thymidine dimers. As it gets to an Okasaki fragment it will begin digesting the DNA in front of it. O It will be more likely to generate mismatched base pairs.

Answer 1

DNA polymerase can polymerise only in 5' to 3' direction.It generally has a 3' to 5' exonuclease activity hich it uses to proof read and check for base pair mismatches, cuts and replaces a nucleotide at that point.In this case this activity has been lost. Therefore this will result in the likely generation of mismatched base pairs.Therefore last option is correct.

It polymerises only only in 5' to 3' direction so first option is wrong and loss of exonuclease activity does not slow its polymerisation so second is wrong, it only polymerises to form okasaki fragments and doesn't digest them, thymine dimers are generally generated by mutations and not by DNA pol activity. DNA pol only fills the gaps when the thymine dimers are removed by other enzymes.