AP BIOLOGY

Detailed explanation-1: -DNA polymerases are the enzymes that build DNA in cells. During DNA replication (copying), most DNA polymerases can “check their work” with each base that they add. This process is called proofreading.

Detailed explanation-2: -Most of the mistakes during DNA replication are promptly corrected by DNA polymerase which proofreads the base that has just been added.

Detailed explanation-3: -The fidelity of DNA replication relies on nucleotide selectivity of replicative DNA polymerase, exonucleolytic proofreading, and postreplicative DNA mismatch repair (MMR).

Detailed explanation-4: -The enzyme responsible for proofreading during replication is called DNA polymerase. DNA polymerase takes an ‘unzipped’ DNA strand and adds in the appropriate nucleotide bases to make two complete double-helix strands.

Detailed explanation-5: -Very few errors are made during DNA replication because DNA polymerase effectively “proof-reads” the new molecules it is making. This enzyme will only link a new nucleotide into the growing chain if the previous one is paired correctly.