Question

Which physical mutagen works through ionizing radiation to break DNA strands?

Options

• UV radiation

• Alpha rays alone

• X-rays and gamma rays

• Beta rays alone

Answer 1

X-rays and gamma rays are ionizing physical mutagens that cause mutations by breaking DNA strands. These high-energy radiations directly damage the phosphodiester backbone and bases, causing double-strand or single-strand breaks that must be repaired, often resulting in mutations if repair is imperfect.