Non-constituitive system with visible light energy breaking covalent T-T bonds Multiple enzymes may repair an A-C error left unrecognized by DNA polymerase Catastrophic DNA damage caused by ultraviolet light can be survived by the cell with this A "spell check" function by the normal replication enzyme to ensure fidelity Thymine dimer-containing section of DNA is cut out, resynthesized and sealed

A. Proofreading
B. Photoreactivation
C. Mismatch repair
D. SOS repair
E. Excision repair