Question

Question 11 1 pts Mismatch repair requires all of the following EXCEPT: Requires the use of a repair DNA polymerase. O is tightly associated with new replicated DNA O Requires information from a nearby homologous chromosome O Makes use of ligase. Uses information on the parental strand to identify the error.

Answer 1

Cells have a variety of mechanisms to prevent mutations, or permanent changes in DNA sequence.
During DNA synthesis, most DNA polymerases "check their work," fixing the majority of mispaired bases in a process called proofreading. Immediately after DNA synthesis, any remaining mispaired bases can be detected and replaced in a process called mismatch repair. If DNA gets damaged, it can be repaired by various mechanisms, including chemical reversal, excision repair, and double-stranded break repair.

DNA mismatch repair (MMR) is a system for recognizing and repairing erroneous insertion, deletion, and mis-incorporation of bases that can arise during DNA replication and recombination, as well as repairing some forms of DNA damage. Mismatch repair is strand-specific.

Steps involved in mismatch repair are:
1. Mismatch is detected in a newly synthesized DNA.
2. The new DNA strand is cut, and its mispaired nucleotide and its neighbours are removed.
3. The missing patch is replaced with the correct nucleotides by a DNA polymerase.
4. A DNA ligase seals the gap in the DNA backbone.

So the step that is not required in mismatch repair from the above options is that it requires information from a nearby homologous chromosome.(c)