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Which of the following repair pathways can accurately repair a double-strand break?

a. base excision repair
b. nucleotide excision repair
c. direct chemical reversal
d. homologous recombination
e. nonhomologous end joining

User Orien
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1 Answer

7 votes

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.

User Mattbawn
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