Which of the following would NOT be considered a mutagen or factor increasing mutation frequency?

Which of the following would NOT be considered a mutagen or factor increasing mutation frequency?

• A. Ultraviolet light
• B. High energy radiation
• C. High energy particles
• D. Pure water

Answer: (D)

Mutagens are agents that raise the rate of genetic mutations by damaging DNA or interfering with replication and repair. Ultraviolet light causes pyrimidine dimers in DNA, which can lead to mispairing during replication if not fixed. High-energy radiation and high-energy particles disrupt DNA through ionization and breaks, increasing the chance of mutations. Pure water, by contrast, does not damage DNA or affect replication on its own, so it does not increase mutation frequency. Therefore, pure water would not be considered a mutagen.

Mutagens are agents that raise the rate of genetic mutations by damaging DNA or interfering with replication and repair. Ultraviolet light causes pyrimidine dimers in DNA, which can lead to mispairing during replication if not fixed. High-energy radiation and high-energy particles disrupt DNA through ionization and breaks, increasing the chance of mutations. Pure water, by contrast, does not damage DNA or affect replication on its own, so it does not increase mutation frequency. Therefore, pure water would not be considered a mutagen.