Cells have evolved several repair mechanisms to maintain genomic integrity:
1. Base Excision Repair (BER): This pathway repairs small, non-helix-distorting base lesions through the removal of damaged bases and resynthesis of the excised region.
2. Nucleotide Excision Repair (NER): NER is responsible for removing bulky, helix-distorting lesions, such as pyrimidine dimers, by excising a short single-stranded DNA segment containing the lesion.
3. Mismatch Repair (MMR): This system corrects base-pair mismatches and insertion-deletion loops that occur during DNA replication.
