The Cellular Metabolic Process in Which a Cell Duplicates One or More Molecules of Dna. DNA Replication Begins When Specific Sequences Known As Origins of Replication Are Recognized and Bound by Initiation Proteins and Ends When the Original DNA Molecule Has Been Completely Duplicated and the Copies Topologically Separated. the Unit of Replication Usually Corresponds to the Genome of the Cell an Organelle or a Virus. the Template For Replication Can Either Be an Existing DNA Molecule or Rna.
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.
Catalysis of the Reaction: Deoxynucleoside Triphosphate + Dna(n) = Diphosphate + Dna(n+1); the Synthesis of DNA From Deoxyribonucleotide Triphosphates in the Presence of a DNA Template and a 3'hydroxyl Group.