During DNA replication, what occurs first in the process?

During DNA replication, the initial step involves the unwinding of the double helix. This is crucial because the two strands of DNA must be separated to allow access to the genetic information contained within them. Enzymes called helicases are responsible for breaking the hydrogen bonds between the base pairs, which leads to the separation of the two strands and creates a replication fork.

Once the strands are unwound, they can serve as templates for synthesizing new DNA strands. The unwinding process is essential for establishing the template strands that RNA primers will later bind to. Without this unwinding, the base pairs would remain in their helical structure, making replication impossible.

The other processes mentioned, such as the synthesis of new DNA strands, the formation of histone proteins, and the attachment of RNA primers, occur after the double helix has been unwound. Therefore, recognizing that unwinding occurs first highlights its foundational role in the replication process.