How does ionizing radiation lead to mutations?

Ionizing radiation leads to mutations primarily by inducing damage to DNA. This damage occurs when ionizing radiation, such as X-rays or gamma rays, interacts with the atomic structure of biological molecules. The energy from the radiation can displace electrons from atoms in DNA, resulting in the formation of free radicals and other reactive species. These highly reactive molecules can then attack the DNA, causing various types of damage such as strand breaks, base modifications, and cross-linking.

When the DNA is damaged, it may not be correctly repaired during the cell's normal repair processes. If the damage is not successfully repaired, or if the repair process is flawed, it can lead to changes in the DNA sequence, which may manifest as mutations. These mutations can affect gene function and potentially lead to various consequences, including cancer or other genetic disorders.

The other options presented do not accurately reflect the mechanism by which ionizing radiation causes genetic mutations. Strengthening the DNA structure or facilitating DNA replication does not pertain to the effects of ionizing radiation. Additionally, while DNA repair mechanisms are essential for maintaining genetic integrity, if ionizing radiation induces significant damage, these repair processes may be overwhelmed or fail, further contributing to mutation formation rather than efficiently repairing the DNA.