Question

If DNA is damaged due to mutations, can it be repaired by DNA polymerase? How?

Answer 1

There is a separate repair mechanism for any damage caused to DNA due to mutation, UV exposure or mismatching that escapes proof-reading mechanism. A nick or break is caused by an endonuclease near the region of repair. DNA polymerase I removes the mismatched or wrong nucleotides if present and synthesizes a correct replacement by using the intact strand as template. The newly formed segment is sealed by DNA ligase.