Question

During which step in the PCR cycle do primers form bonds with a single-stranded template?

A) Extension
B) Denaturation
C) All of these steps
D) Annealing

Answer 1

Primers form bonds with a single-stranded DNA template during the annealing step of the PCR cycle.

Step-by-step explanation:

During the Polymerase Chain Reaction (PCR) cycle, primers form bonds with a single-stranded template during the annealing step. PCR consists of three primary steps which are: denaturation, annealing, and extension. The denaturation step involves heating the DNA to separate the two strands. The annealing step involves cooling the DNA so that primers can attach to their complementary bases on the single-stranded DNA. Finally, during the extension step, the DNA polymerase extends the strand from the primer to create new DNA fragments. Therefore, the correct answer to the student's question is D) Annealing.