Which of the following DNA repair mechanisms is correctly defined?

Question

Quizplus · Accepted Answer

Base excision repair is a type of DNA repair mechanism that uses DNA glycosylase to remove a damaged base by cleaving the glycosidic bond. This is followed by the removal of the sugar and subsequent replacement with a new nucleotide. This mechanism is specific for small, non-helix-distorting lesions, such as oxidized or deaminated bases, and does not involve cutting the phosphodiester backbone.

Answer: B
 Photolyase is a type of DNA repair enzyme that uses light energy to break the covalent bonds of cyclobutane dimers that are formed between adjacent pyrimidine residues (usually cytosine) in DNA due to exposure to ultraviolet light. This mechanism is specific for UV-induced damage and does not involve cutting the phosphodiester backbone.

Answer: A, D
 The mismatch repair system (A) corrects errors that occur during DNA replication, such as mismatches, insertions, or deletions, that can arise due to errors in DNA synthesis or DNA damage. Nucleotide excision repair (D) is a type of DNA repair mechanism that removes larger helix-distorting lesions, such as thymine dimers, by cutting the phosphodiester backbone on either side of the lesion and replacing it with a new nucleotide.

Which of the Following DNA Repair Mechanisms Is Correctly Defined