What is the first stage in semi-conservative replication of DNA?

In semi-conservative replication of DNA, the first stage involves the unwinding of the double helix structure of the DNA molecule. This process is critical as it allows for each strand of the DNA to serve as a template for the synthesis of a new complementary strand. During this unwinding, the hydrogen bonds that hold the two strands together are disrupted, leading to the separation of the strands.

By progressing with the unwinding, the replication machinery can access the bases on each strand, which is essential for the next steps in the replication process. This stage is not just about separating the strands but also about preparing the DNA for effective replication, ensuring that each template strand is exposed and ready for the addition of complementary nucleotides.