AP BIOLOGY

Detailed explanation-1: -The portion of DNA polymerase responsible for checking the accuracy of new nucleotides is the DnaQ protein (ɛ-subunits).

Detailed explanation-2: -This exonuclease activity is called the proofreading or editing function of DNA polymerase I. Pol I also has a unique 5′ to 3′ exonuclease activity that is required for its DNA repair function.

Detailed explanation-3: -The -subunit contains the 5′–3′ DNA polymerase active site (2, 3), the ɛ-subunit is responsible for 3′–5′ proofreading exonuclease activity (4) and the -subunit has no identified enzymatic activity (5).

Detailed explanation-4: -Mitochondrial DNA is replicated and repaired by DNA polymerase (Pol ). Pol , encoded by the POLG gene, is the only polymerase found in animal cell mitochondrial and is involved in replication, mutagenesis, and repair of mtDNA as well is a target of antiviral nucleoside analogs that cause mitochondrial toxicity.

Detailed explanation-5: -In bacteria, all three DNA polymerases (I, II and III) have the ability to proofread, using 3’