Q1: In E.coli, which enzyme synthesizes the RNA primer for Okazaki fragments?

ANS:C - DnaG

All known DNA polymerases require a pre-existing "primer" from which to begin replication. E. Coli uses an RNA primer which is synthesized by an enzyme called DnaG (primase). DnaG makes RNA primers (about 10 nucleotides long) that are used by DNA pol III holoenzyme to start DNA synthesis. DnaG acts distributively (does not remain associated with DNA). It drops off DNA after primer synthesis, then reloads onto DNA a second or so later by protein-protein interactions with DnaB (helicase) to synthesize the next primer on the lagging strand. There are many places along the template where RNA primers can be made by primase.