Final answer:
b) Denaturation of DNA strands. The function of the heat step in PCR is the denaturation of DNA strands, which separates the double-stranded DNA into single strands, enabling further steps of PCR.
Step-by-step explanation:
In Polymerase Chain Reaction (PCR), the function of the heat step is b) Denaturation of DNA strands. During the PCR cycle, the initial high-temperature step involves heating the DNA to break the hydrogen bonds between the double-
stranded DNA, thereby creating two single strands of DNA. This step is crucial as it prepares the DNA strands for the subsequent stages of PCR, which are annealing,
where primers attach to the single-stranded DNA at a lower temperature, and extension, where a DNA polymerase extends the strand from the primer to create new DNA fragments. Each PCR cycle includes these three steps,
with the high-temperature denaturation phase being essential for the replication process to proceed.
In Polymerase Chain Reaction (PCR), the function of the heat step is to denature the DNA strands. Denaturation involves heating the DNA to break the hydrogen bonds holding the two DNA strands together, resulting in two separate single strands of DNA.
This step is crucial because it allows the primers to bind to the single strands in the subsequent annealing step.