What consequence might occur if a cell fails to repair a double-strand DNA break?

If a cell fails to repair a double-strand DNA break, one of the primary consequences is cell death or senescence. Double-strand breaks are one of the most severe forms of DNA damage, and if they are not properly repaired, they can lead to genomic instability. This instability can disrupt essential cellular processes, potentially leading to apoptosis (programmed cell death) or senescence (an irreversible state of cell cycle arrest).

When a cell encounters a double-strand break, it typically activates repair mechanisms such as homologous recombination or non-homologous end joining. If these repair pathways are ineffective due to various factors, including the presence of mutations or deficiencies in repair proteins, the cell may initiate apoptosis to prevent propagation of potentially damaged DNA. On the other hand, if the cell enters a senescent state, it stops dividing but remains metabolically active, which can have further implications for tissue function and aging.

Normal cellular function, cell cycle progression, and increased cellular replication are unlikely outcomes in the presence of unaddressed double-strand breaks because the integrity of the genome is compromised, making it difficult for the cell to maintain standard operations. Thus, the risk of losing control over cell division and function is significantly increased, which is why