Question

Which type 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 have been attached?

1) nucleotide excision repair
2) base excision repair
3) mismatch repair
4) double-strand breakage repair
5) all of the above

Answer 1

Nucleotide excision repair (NER) removes parts of the DNA strand with bulky lesions like pyrimidine dimers and nucleotides with attached chemical groups. Enzymes recognize the damage and replace the damaged DNA strand with the correct nucleotides.

Step-by-step explanation:

The type of DNA repair that removes the parts of the strand having certain types of bulky lesions, such as pyrimidine dimers and nucleotides to which various chemical groups have been attached, is nucleotide excision repair (NER).

In NER, enzymes recognize bulky, helix-distorting changes and remove the damaged DNA strand, replacing it with the correct nucleotides. This repair mechanism is often used when UV exposure causes the formation of pyrimidine dimers.