5 What would be most likely to happen if there is a strain o

5) What would be most likely to happen if there is a strain of E. coli that has a mutation in the DNA polymerase III gene that abolished its exonuclease activity only.

A) There would be no base mismatch repair, but bases damaged by U.V. or mutagens could be repaired.

B) DNA replication would produce DNA with increased mismatches that could not be repaired after replication.

C) DNA replication would cease.

D) Bases damaged by U.V. or mutagens would not be repaired but mismatched bases could be repaired.

E) DNA replication would produce DNA with increased mismatches that could be repaired after replication.

Solution

E. DNA replication would produce DNA with increased mismatches that could not be repaired after replication.

if the exonuclease activity is not there the mismatch repair can not be repaired. EXO1 enzymechops out a segment of the mutant strand. Then a DNA polymerase can replace the missing section of the strand with a new section and the mistake is repaired.