How is broken DNA repaired? Homologous recombination, animated (opens in new tab)

Every minute, the DNA inside human cells is under attack from things like radiation, toxins, and normal wear-and-tear. Most fixes are simple, but sometimes both strands of DNA snap, an injury called a “double-strand break.” Left unrepaired, this damage can lead to apoptosis (programmed cell death) or senescence (where the...