Which term names the site where replication begins?

Which term names the site where replication begins?

• A. Origin of Replication
• B. Replication Fork
• C. RNA Primer
• D. Helicase

Answer: (A)

DNA replication starts at specific locations on the chromosome called origins of replication. These sites are recognized by initiator proteins that recruit the rest of the replication machinery, including helicase, to unwind the DNA and form the replication bubble with two forks that proceed in opposite directions. The origin is the starting point of replication, which is why it’s the best term for where replication begins. The other terms describe things at the replication forks or the helpers involved: the replication fork is the Y-shaped junction where unwinding and synthesis occur; an RNA primer provides the starting 3' end for DNA polymerase; helicase is the enzyme that unwinds the double helix. All are essential, but only the origin of replication denotes the actual starting site.

DNA replication starts at specific locations on the chromosome called origins of replication. These sites are recognized by initiator proteins that recruit the rest of the replication machinery, including helicase, to unwind the DNA and form the replication bubble with two forks that proceed in opposite directions. The origin is the starting point of replication, which is why it’s the best term for where replication begins. The other terms describe things at the replication forks or the helpers involved: the replication fork is the Y-shaped junction where unwinding and synthesis occur; an RNA primer provides the starting 3' end for DNA polymerase; helicase is the enzyme that unwinds the double helix. All are essential, but only the origin of replication denotes the actual starting site.