<prompt> Effect of ultraviolet radiation on DNA is formation ofPurine dimersPyrimidine dimersDNA-DNA cros linkingAll of the above  <response>: UV light causes the formation of thymine dimers, where covalent bonds are formed between adjacent thymine residuesSince repair mechanism is not operating these mutations are accumulated, leading to cancerRef: DM Vasudevan, 7th edition, page no: 584 