Denaturation is a step in the procedure called polymerase chain Reaction . This step does not involve which of the following process ?

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 step in the polymerase chain reaction (PCR), we will analyze each of the provided options to determine which process is not involved in denaturation.

### Step-by-Step Solution:

1. **Understanding Denaturation in PCR**:
- Denaturation is the first step in the PCR process.
- It involves heating the DNA to a high temperature (around 94°C) to break the hydrogen bonds between the two strands of the DNA double helix, resulting in single-stranded DNA templates.

2. **Analyzing the Options**:
- **Option A**: Breaking of hydrogen bonds of original DNA double helix.
- This is a key part of denaturation. Therefore, this option is involved in denaturation.

- **Option B**: Heating of starting solution at 94°C.
- This is the temperature at which denaturation occurs. Hence, this option is also involved in denaturation.

- **Option C**: Addition of nucleotides to the primer by DNA polymerase.
- This process occurs during the extension step of PCR, not during denaturation. Therefore, this option is NOT involved in denaturation.

- **Option D**: Creation of single-stranded DNA templates.
- This is a direct result of the denaturation process, as the double-stranded DNA separates into single strands. Thus, this option is involved in denaturation.

3. **Conclusion**:
- The correct answer is **Option C**: Addition of nucleotides to the primer by DNA polymerase, as this process does not occur during the denaturation step of PCR.

### Final Answer:
**Option C**: Addition of nucleotides to the primer by DNA polymerase.

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