Which of the following is NOT a type of DNA repair mechanism?

Gene amplification is not a type of DNA repair mechanism. Instead, it refers to the process by which certain genes are duplicated, leading to an increased number of copies within the genome. This mechanism often contributes to genetic changes that can promote cancer or other diseases by enabling the overexpression of certain proteins.

In contrast, mismatch repair, base excision repair, and nucleotide excision repair are all essential pathways involved in correcting specific types of DNA damage. Mismatch repair corrects errors that occur during DNA replication when the wrong nucleotide is incorporated. Base excision repair addresses small, non-helix-distorting lesions in the DNA, such as deaminated bases. Nucleotide excision repair is responsible for removing bulky DNA adducts or helix-distorting damage caused by environmental factors, like UV radiation. Each of these repair mechanisms plays a critical role in maintaining genomic stability and preventing mutations that could lead to disease.