Question

Which of the following answers is incorrect?

Nucleotide Excision Repair is a pathway that _________

utilizes some helicases from TFIIH complex such as XPB and XPD.

repairs double stranded DNA breakage.

involves DNA synthesis.

repairs bulky DNA adducts/lesions caused by UV radiation and some chemicals.

has two sub-pathways one for transcribed DNA and the other for non-transcribed DNA.

Answer 1

Answer: Correct answer is option-3.

Explanation: The mechanism of nucleotide excision repair is involved in the repairing process of DNA. This damage is caused due to formation of pyrimidine dimers in the presence of UV radiation. These dimers are removed by the different steps involved in the pathway of NER. However, NER machinery is not directly linked to the DNA synthesis. During the process of repairing the adduct/lesion, it involves the exonuclease activity and only that gap is filled with polymerase. NER doesn't synthesise the whole stretch of DNA.