'Light' Part 3 - How does sunlight damage DNA?

We all know we should be careful when in the sun, but Prof Catherine Green's interests lie in understanding how Human cells manage to copy the enormous amounts of DNA they have without making mistakes and how they cope with threats; like sunlight. Cath describes what happens when DNA gets damaged and how her work seeks to understand the cellular machinery involved in copying and repairing DNA. She also discusses other threats and risks, how other animals protect themselves from sunlight and how understanding these processes better will help us understand disorders, everyone's risks and develop more targeted treatments.