Which factor contributes to increased radiosensitivity during cell division?

Increased radiosensitivity during cell division is primarily linked to the rate of division. Cells that are actively dividing and replicating their DNA tend to be more vulnerable to radiation damage because radiation can disrupt cellular processes, especially during the critical phases of the cell cycle, such as the synthesis (S) phase and mitosis (M) phase.

During these phases, the DNA is more open to being affected by ionizing radiation, leading to potential breaks or mutations. This increased susceptibility during division is a key principle in understanding how radiation impacts rapidly dividing tissues, such as those found in bone marrow or the lining of the gastrointestinal tract, which are consistently undergoing division.

While metabolism, health of the organism, and size of the cell can influence overall cell function and resilience to various stresses, they are not direct factors that increase radiosensitivity in the same way that the rate of division does. Thus, the rate at which a cell divides is the most critical factor contributing to its sensitivity to radiation exposure.