Question

During the annealing step of PCR, why does the primer bind to the separate DNA strands rather than the two DNA strands binding together?

Answer 1

During the annealing step of PCR, the primer binds to the separate DNA strands because the primer sequences are complementary to the DNA strands, allowing for specific binding. This enables the synthesis of the desired DNA product.

Step-by-step explanation:

During the annealing step of PCR, the primer binds to the separate DNA strands rather than the two DNA strands binding together because the primer sequences are complementary to the single DNA strands. The annealing temperature is set lower than the denaturation temperature to ensure that the primers can bind specifically to the DNA strands. This allows the DNA polymerase to extend the primers and synthesize the desired DNA product.