Which of he following is'the correct sequence of PCR or polymerase chain reaction

Options

A. Denaturation `rarr` Annealing `rarr` Extension
B. Extension `rarr` Denaturation `rarr` Annealing
C. Annealing `rarr` Extension `rarr` Denaturation
D. Denaturation `rarr` Extension `rarr`Annealing

Answer

To determine the correct sequence of the Polymerase Chain Reaction (PCR), we need to understand the fundamental steps involved in this process. Here’s a step-by-step breakdown:

### Step 1: Denaturation
- The first step in PCR is denaturation, where the double-stranded DNA is heated to a high temperature (typically around 94-98°C). This causes the hydrogen bonds between the base pairs to break, resulting in the separation of the two strands of DNA.

### Step 2: Annealing
- After denaturation, the temperature is lowered (usually to about 50-65°C) to allow short DNA primers to bind (or anneal) to the complementary sequences on the single-stranded DNA templates. This step is crucial for initiating the synthesis of new DNA strands.

### Step 3: Extension (or Polymerization)
- The final step is extension, where the temperature is raised again (typically to around 72°C). The enzyme Taq polymerase synthesizes new DNA strands by adding nucleotides to the 3' end of the primers, effectively creating new copies of the target DNA sequence.

### Conclusion
- The correct sequence of the PCR process is:
1. Denaturation
2. Annealing
3. Extension (or Polymerization)

### Final Answer
The correct sequence of PCR is: **Denaturation → Annealing → Extension.**

---