This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'Uv radiation has which of the following effects on cell \nSelect and explain. \nA. Prevents formation of pyrimidine dimers, B. Stimulates formation of pyrimidine dimers, C. Prevents formation of purine dimers, D. All the above', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ref Robbins 8/e p312, 9/e p314 The carcinogenicity of UV_B light is attributed to it's formation of pyrimidine dimmers in DNA.this type of DNA amage is repaired by the nucleotide extension repair pathway of DNA repair is illustrated by hight frequency of cancers in individuals with the hereditary disorder xeroderma pigmentosum", 'role': 'assistant'}]