Final answer:
Mismatch repair, base excision repair, and nucleotide excision repair are similar in that each uses an undamaged segment of DNA as the template for repair (Option A).
Step-by-step explanation:
Mismatch repair, base excision repair, and nucleotide excision repair are all fundamental DNA repair mechanisms that ensure the integrity of genetic material. One thing they have in common is each uses an undamaged segment of DNA as the template for repair. In mismatch repair, the process targets incorrect bases that have been incorporated during replication, identifying and excising them based on methylation patterns in the template DNA, with the help of specialized enzymes such as Muts, MutL, and MutH, as well as exonucleases, DNA polymerase III, and ligase to correct the mistake.
On the other hand, nucleotide excision repair specializes in repairing bulky lesions, such as pyrimidine dimers caused by UV damage, that distort the DNA helix by removing a short single-stranded segment of DNA around the damage. Crucial enzymes involved include UvrABC endonuclease and DNA polymerases and ligases. By making cuts on both the 3' and 5' ends of the damage, this pathway can excise and subsequently replace several nucleotides to maintain genomic stability.
Base excision repair deals with individual damaged bases such as those caused by oxidation or deamination. Specific glycosylases locate and remove the incorrect base, after which the sugar-phosphate backbone is cleaved, the correct base is inserted, and the nick is sealed.
Thus, the correct option is A.