The denaturation process in polymerase chain Reaction (PCR) does not involve

Options

A. breaking of hydrogen bonds of the original DNA double helix
B. heating of starting solution to `94^@C`
C. addition of nucleotides to the primer by DNA polymerase
D. creation of single-stranded DNA templates

Answer

To solve the question regarding the denaturation process in the polymerase chain reaction (PCR), we need to understand what occurs during this specific step of the PCR process.

### Step-by-Step Solution:

1. **Understanding PCR**: The polymerase chain reaction (PCR) is a technique used to amplify specific DNA sequences. It involves three main steps: denaturation, annealing, and extension.

2. **Denaturation Process**: The first step in PCR is denaturation. During this step, the double-stranded DNA (dsDNA) is heated to separate it into two single strands. This is typically done at a temperature around 94°C.

3. **Breaking of Hydrogen Bonds**: The denaturation process involves breaking the hydrogen bonds that hold the two strands of the DNA helix together. This is a critical part of the denaturation step, as it allows the strands to separate.

4. **Temperature**: The heating of the solution to 94°C is essential for denaturation. This high temperature is necessary to disrupt the hydrogen bonds between the base pairs of the DNA.

5. **Addition of Nucleotides**: During the denaturation step, nucleotides are not added. The addition of nucleotides occurs in the extension phase, where DNA polymerase synthesizes new DNA strands based on the template provided by the single-stranded DNA.

6. **Conclusion**: The statement that does not involve the denaturation process is the addition of nucleotides to the primer by DNA polymerase. This occurs in the extension phase, not during denaturation.

### Final Answer:
The denaturation process in polymerase chain reaction (PCR) does not involve the addition of nucleotides to the primer by DNA polymerase.

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