Nucleotide excision repair of thymine dimers
Which repair pathway removes thymine dimers caused by UV light?
Answer C: explanation for every choice
A
Mismatch repair fixes incorrectly paired bases left after replication.
B
Base excision repair removes single damaged bases, such as uracil from deaminated cytosine.
C
Correct. NER removes bulky, helix-distorting lesions. Defects cause xeroderma pigmentosum.
D
Nonhomologous end joining repairs double-strand breaks.
TakeawayBulky lesions such as thymine dimers → nucleotide excision repair.
Next question →
Reviewed 2026-11-05 by a medical student. Spot an error? Report it with question ID bb38.