| Mechanism | Types and pathways and comments | 
   
  | 1. Structural organization of the genome | 1. Nuclear genome. 2. Mitochondrial genome
 | 
   
  | 2. Structural features of DNA | Complementary strand stores genetic information | 
   
  | 3. Degeneracy of the genetic code | Multiple point mutations might occur without affecting  synthesized protein | 
   
  | 4. Nuclear localization of DNA | Physical protection of nuclear genome | 
   
  | 5. DNA-associated proteins | 1. Physical barriers 2. Biochemical buffers
 3. Deactivating biomolecules
 4. Modulation of charge transport
 5. Limitation of DNA helix distortion
 | 
   
  | 6. Replication proofreading system | Prophylactic pathway during DNA replication | 
   
  | 7. Genetic repair systems | A. Nuclear DNA repair 1. Base excision repair.
 2. Nucleotide excision repair
 3. Direct reversal repair.
 4. Mismatch repair
 5. Recombination repair
 B. RNA repair/editing system
 Post-transcription repair/editing of some mRNA defects via guide RNA (gRNA)/editosome complex
 C. Mitochondrial DNA (mtDNA) repair
 | 
   
  | 8. Protein repair systems | Correction of post-translation protein misfolding/aggregation by chaperones | 
   
  | 9. Silencing of transposons by piwiRNA | Reduces transposon-induced mutations during development | 
   
  | 10. Antioxidant enzyme systems |  | 
   
  | 11. Apoptosis | Prophylactic pathway against spread of mutations of heavily or lethally mutated genomes to daughter cells | 
   
  | 12. Melatonin | Anti-clastogenic, anti-mutagenic, anti-carcinogenic and anti-oxidant compound. |