Following exposure to ionizing radiation, single-strand breaks in a DNA molecule are most likely to result in:

When ionizing radiation interacts with DNA, it can cause various types of damage, including single-strand breaks (SSBs). SSBs are generally less severe than double-strand breaks (DSBs) and can often be repaired effectively by the cell's repair mechanisms. The cell has evolved robust mechanisms, such as the base excision repair pathway, to recognize and repair these breaks.

The concept that SSBs can be repaired without negative effects on the DNA molecule is grounded in the efficiency of these repair systems. If the repair is successful, the integrity of the DNA is restored, and no permanent mutation occurs. This ability to repair the damage is crucial for maintaining genomic stability and cell function.

In contrast, while SSBs could theoretically lead to cell death if the repair mechanisms fail or are overwhelmed, this is less common compared to the repair outcomes. The likelihood of immediate apoptosis occurring due to SSBs is also low, as apoptosis is more typically associated with extensive damage or other forms of stress. Therefore, recognizing that single-strand breaks often result in repair without lasting effects underscores the resilience of cellular repair processes in the face of radiation exposure.