DNA polymerase editing

DNA PHOTO LYASES DNA POLYMERASES EDITING MECHANISMS DNA repair,... 

The answer is d. (Murray, pp 435—451. Scriver, pp 3—45. Sack, pp 1-40. Wilson, pp 101-120.) DNA synthesis cannot occur until an RNA primer is made. A specific type of RNA polymerase called primase synthesizes a short stretch of RNA of about five nucleotides that is complementary to the template DNA strand in duplex DNA near the replication fork. This function cannot be carried out by DNA polymerase. In contrast, both DNA polymerase and RNA polymerase work in the 5 to 3 direction and add nucleoside monophosphates from nucleotide triphosphates to the growing polynucleotide chains of DNA or RNA. Only DNA polymerase edits as it synthesizes DNA and fills the gap between Okazaki fragments. 

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