Which enzymatic activity allows DNA polymerases to excise mispaired bases immediately during replication?
Answer and explanation
Correct answer: B. 3'-to-5' exonuclease activity
Proofreading relies on 3'-to-5' exonuclease activity, which removes the mismatched terminal nucleotide immediately before synthesis resumes. 5'-to-3' exonuclease activity is used to degrade RNA primers, not for proofreading.
Practise more Cellular Biology and Molecular Genetics.
Free questions with an explanation for every one, and full timed Medical University Entrance Examination (Bulgaria) mock tests.
More Cellular Biology and Molecular Genetics questions
- What is the primary role of cholesterol in mammalian plasma membranes at low temperatures?
- Which stoichiometry characterizes one complete cycle of the Na+/K+-ATPase pump?
- How does D-glucose cross the apical membrane of small intestinal enterocytes?
- Which protein complex forms the coat of vesicles involved in receptor-mediated endocytosis of LDL?
- In which cellular subcompartment does oxidative decarboxylation of pyruvate to acetyl-CoA take place?
- Which respiratory chain complex transfers electrons directly to molecular oxygen in mitochondria?