Western Governors University (WGU) CHEM3501 C624 Biochemistry Objective Assessment Practice Exam

During the elongation phase of polymerase chain reaction (PCR), DNA Polymerase plays a crucial role by synthesizing new DNA strands. After the primers have annealed to the template DNA during the preceding step, the DNA Polymerase enzyme moves along the template strand and adds nucleotides to the growing chain, effectively creating a complementary strand of DNA. This process continues as long as there are available nucleotides and the enzyme remains active, allowing for exponential amplification of the target DNA sequence.

The significance of this step lies in its ability to produce a large quantity of DNA, which is essential for various applications like cloning, sequencing, or forensic analysis. The specificity of the primers is vital, as they dictate the exact portion of the DNA that is amplified during this phase, ensuring that the correct segment is replicated.

In contrast, the other processes mentioned involve different phases of PCR. DNA strands are separated during the denaturation phase, primers attach to the DNA in the annealing phase, and while base pair repairs can be a function of certain polymerases in cellular contexts, it is not a primary event of the elongation phase in PCR.