Can UV light induce mutations in DNA?

Ultraviolet (UV) light is a form of radiation that can indeed induce mutations in DNA, primarily through the formation of thymine dimers. When DNA is exposed to UV light, adjacent thymine bases can covalently bond to one another instead of pairing with adenine across the DNA strand. This creates a distortion in the DNA structure, which can lead to errors during DNA replication if not properly repaired.

The repair mechanisms, such as nucleotide excision repair, can fix these dimers; however, if the damage is not repaired or the repair processes fail, it can result in mutations. This mutation can have various biological consequences, including the potential for cancers, making UV light a significant mutagenic agent in living organisms.

Other options do not provide a complete understanding of the capability of UV light to induce mutations. While bacteria can be affected by UV light, it is not exclusive to them; all organisms, including humans, are susceptible to the mutagenic effects of UV radiation. Additionally, the formation of thymine dimers occurs with the exposure to UV light regardless of water’s presence, though water can play a role in the broader context of DNA repair processes.