Dimerization of adjacent thymine bases Adenine finds itself paired with cytosine after a tautomeric shift Catastrophic chromosome breakage following exposure to gamma radiation Uracil incorporation into DNA A. Base excision repair B. Nonhomologous end joining C. Mismatch repair D. Photolyase

Photolyase is the mechanism that is used in the process of the DNA repair in the cells where dimerization of the adjacent thyamine bases.

Mismatch repair occurs due to tautomeric shift that leads to the pairing in between adenine with cytosine.

Non homologous chromosome end joining is the process of the Ligating without end without any requirement of homologous template.

Damaged Bases of DNA is remove and replaced is through the process of the base excision repair, in this process only damaged base is remove.