AP BIOLOGY

Detailed explanation-1: -During proofreading, DNA polymerase enzymes recognize this and replace the incorrectly inserted nucleotide so that replication can continue. Proofreading fixes about 99% of these types of errors, but that’s still not good enough for normal cell functioning.

Detailed explanation-2: -Nucleotide excision-repair uses DNA polymerases delta or epsilon to resynthesize the bases removed during repair of pyrimidine dimers and other bulky adducts in DNA. Similarly, mismatch-repair of replication errors appears to involve DNA polymerases delta or epsilon.

Detailed explanation-3: -The polymerase checks whether the newly added base has paired correctly with the base in the template strand. If it is the right base, the next nucleotide is added. If an incorrect base has been added, the enzyme makes a cut at the phosphodiester bond and releases the wrong nucleotide.

Detailed explanation-4: -DNA polymerase is responsible for the process of DNA replication, during which a double-stranded DNA molecule is copied into two identical DNA molecules.

Detailed explanation-5: -The DNA repair is done by enzyme DNA polymerase. Most of the mistakes during DNA replication are promptly corrected by DNA polymerase. DNA polymerase proofreads the base that has just been added. In proofreading, the DNA pol reads the newly-added base before adding the next one so a correction can be made.