The Process of Restoring DNA After Damage. Genomes Are Subject to Damage by Chemical and Physical Agents in the Environment (e.g. Uv and Ionizing Radiations Chemical Mutagens Fungal and Bacterial Toxins Etc.) and by Free Radicals or Alkylating Agents Endogenously Generated in Metabolism. DNA Is Also Damaged Because of Errors During Its Replication. a Variety of Different DNA Repair Pathways Have Been Reported That Include Direct Reversal Base Excision Repair Nucleotide Excision Repair Photoreactivation Bypass Double Strand Break Repair Pathway and Mismatch Repair Pathway.
A System For the Correction of Errors in Which an Incorrect Base Which Cannot Form Hydrogen Bonds with the Corresponding Base in the Parent Strand Is Incorporated Into the Daughter Strand. the Mismatch Repair System Promotes Genomic Fidelity by Repairing Base Base Mismatches Insertion Deletion Loops and Heterologies Generated During DNA Replication and Recombination.