Here's why:

* Replication starts at specific points: DNA replication doesn't happen randomly along the entire DNA molecule. It begins at specific, designated locations called origins of replication.

* Multiple origins: In eukaryotes (organisms with complex cells), there are multiple origins of replication along each chromosome, allowing for faster and more efficient DNA duplication.

* Initiation complex: At each origin, proteins called initiator proteins bind to the DNA and unwind the double helix, creating a replication fork where the new strands are synthesized.

Let me know if you have any other questions about DNA replication!