Which of the Following Statements About Sequence Proofreading During DNA

Question

Which of the following statements about sequence proofreading during DNA replication is FALSE?
A)The exonuclease activity is in a different domain of the DNA polymerase.
B)The exonuclease activity cleaves DNA in the 5′-to-3′ direction.
C)The DNA proofreading activity occurs concomitantly with strand elongation.
D)If an incorrect base is added, it is "unpaired" before removal.

Accepted Answer

The exonuclease activity involved in proofreading during DNA replication cleaves DNA in the 3′-to-5′ direction, not the 5′-to-3′ direction. This allows the polymerase to remove incorrectly paired bases immediately after they are incorporated, ensuring high fidelity in DNA replication.