This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
UV radiation has which of the following effects on the cells 
Select and explain. 
A. UV radiation has which of the following effects on the cells, B. Stimulates formation of pyrimidine dimers, C. Prevents formation of purine dimers, D. All of the above
B: Stimulates formation of pyrimidine dimers
Answer: B: Stimulates formation of pyrimidine dimers 
Explanation: Direct quote from Robbins.. “The carcinogenicity of UV-B light is attributed to its formation of pyrimidine dimers in DNA”. This type of DNA damage is repaired by the nucleotide excision repair pathway. The importance of the nucleotide
excision repair pathway of DNA repair is illustrated by the high frequency of cancers in individuals with the hereditary disorder xeroderma pigmentosum..