What does the reverse primer do during PCR?

The reverse primer plays a crucial role in the PCR (Polymerase Chain Reaction) process by providing a starting point for DNA synthesis. It binds to the complementary strand of the DNA template, specifically at a region adjacent to the target sequence. This binding allows the DNA polymerase enzyme to extend the primer and synthesize new DNA.

When focusing on the function of the reverse primer, it's important to note that it does not interact with the stop codon of the template strand. Instead, it is complementary to the sequence that follows the target area on the opposite strand. This means it facilitates the amplification of the desired DNA segment by enabling the polymerase to build a strand in the 5' to 3' direction, effectively leading to the duplication of the target DNA region.

In this context, other options do not accurately describe the role of the reverse primer. The primer does not bind to a start codon, does not assist in denaturing DNA, and does not lead to RNA synthesis, as its primary purpose is to initiate DNA amplification during PCR. Overall, the correct choice highlights the fundamental nature of how reverse primers function in the replication process being utilized in molecular biology.