Question

a patient with xeroderma pigmentosum lacks nucleotide excision repair proteins. when exposed to sunlight, what mechanism is most compromised?
dna replication fidelity
repair of uv - induced thymine dimers
mismatch recognition
chromosome segregation
telomere maintenance

Explanation:

Nucleotide - excision repair is crucial for fixing UV - induced DNA damage like thymine dimers. Xeroderma pigmentosum patients lacking these repair proteins have compromised repair of such damage.

Answer:

Repair of UV - induced thymine dimers