Final answer:
The Y-shaped region where DNA is unwound to start replication is called a replication fork. It forms at the origin of replication when helicase unwinds the DNA, and is stabilized by single-strand binding proteins.
Step-by-step explanation:
The Y-shaped region where DNA is unwound at the start of replication is called a replication fork. This occurs during the process called DNA replication, where the DNA molecule makes an exact copy of itself
. Replication begins at specific locations in the genome, known as origins of replication. Here, a group of proteins and enzymes work together to open the double helix and commence the replication process.
Helicase is the enzyme responsible for unwinding the DNA, causing the formation of the replication fork. In addition to helicase, topoisomerases and single-strand binding proteins play crucial roles in DNA unwinding and stabilization.