Final answer:
Homologous recombination and nonhomologous end joining are the repair pathways that can accurately repair a double-strand break in DNA.
Step-by-step explanation:
The repair pathways that can accurately repair a double-strand break in DNA are homologous recombination and nonhomologous end joining. Homologous recombination repairs double-strand breaks with the aid of a number of enzymes and proteins that utilize a homologous sequence as a template for repair. Nonhomologous end joining, on the other hand, directly joins the broken DNA ends without the need for a template, which can result in the loss or addition of a few nucleotides at the junction, potentially leading to mutations.
Base excision repair and nucleotide excision repair are involved in fixing single-stranded DNA damage, such as incorrect bases or bulky helix-distorting lesions like thymine dimers. Direct chemical reversal is a mechanism where enzymes like photolyase directly reverse certain kinds of damage such as thymine dimers caused by UV light.