Question

Which the of DNA repair removes the part of the strand having certain types of bulky lesions, like pyrimidine dimers and nucleotides to which various chemical groups?

a. nucleotide excision repair
b. base excision repair
c. mismatch repair
d. double-strand breakage repair
e. all of the above

Answer 1

Nucleotide excision repair is the type of DNA repair that removes bulky lesions like pyrimidine dimers. Enzymes replace damaged bases by making cuts on both ends of the lesion, removing the segment of DNA, and replacing it with the correct nucleotides.

Step-by-step explanation:

The type of DNA repair that removes the part of the strand having certain types of bulky lesions, like pyrimidine dimers and nucleotides to which various chemical groups, is nucleotide excision repair. In this repair mechanism, enzymes replace damaged bases by making cuts on both the 3' and 5' ends of the damaged base. The segment of DNA with the lesion is then removed and replaced with the correctly paired nucleotides by the action of DNA polymerase. This repair mechanism is particularly important in correcting thymine dimers caused by UV exposure.