In the context of DNA repair and recombination, which cellular component is most directly damaged by UV radiation, creating lesions such as cyclobutane pyrimidine dimers?

• A. Nuclear DNA (the genome), where UV induces pyrimidine dimers that distort the DNA helix
• B. Microtubule proteins in the cytoskeleton, which undergo UV-triggered double-strand breaks
• C. Ribosomal RNA in the nucleolus, which is primarily cleaved into fragments by UV exposure
• D. Plasma membrane phospholipids, which are the main targets of UV-induced base modifications

Answer: (A)