DNA mostly relies on the fact that there's 2 strands that are (logically speaking) a mirror copy of each other (a C is paired with a G and vice versa, an A to a

DNA mostly relies on the fact that there's 2 strands that are (logically speaking) a mirror copy of each other (a C is paired with a G and vice versa, an A to a T and vice versa), it's like RAID 3 with only 2 disks (one being parity). Apart from repairing structural damage such as missing bonds, the cell can even repair missing bases or non-straight breaks without loss. This mechanism is also used for replication: the entire strand is split and each half is completed with its mirror counterpart.