The proofreading DNA repair system differs from other types of DNA repair in that it
A) does not actually decrease the mutation rate.
B) can only occur in prokaryotes.
C) can only occur in eukaryotes.
D) occurs as DNA is being replicated.
E) removes abnormal bases that have formed because of chemical damage.

Question

Quizplus · Accepted Answer

The proofreading DNA repair system occurs during DNA replication and involves the correction of errors made during that process. This differs from other types of DNA repair, such as nucleotide excision repair or base excision repair, which remove abnormal or damaged bases that were not caused by replication errors. Option A is incorrect because the proofreading system does decrease the mutation rate by fixing replication errors. Options B and C are incorrect because the proofreading system can occur in both prokaryotes and eukaryotes. Option E is incorrect because it describes a different type of DNA repair.

The Proofreading DNA Repair System Differs from Other Types of DNA