How is the DNA unwound at the replication fork What effect d

How is the DNA unwound at the replication fork? What effect does this have on the DNA upstream of the fork, and how does the cell deal with this effect?

Solution

By use of enzyme called DNA helicase which unwinds the DNA double helix which happens by breaking the hydrogen bonds and this process begins at origin of replication, via a replication fork is created.

Bacause of this DNA ahead is forced to rotate and process results in a twists in the DNA ahead which eventually halt the progress of the replication fork. This tension get rid with the owrk of enzyme  Topoisomerases that temporarily break the strands of DNA