The optimum temperature for polymerisation in PCR is __________ while the enzyme responsible for the mentioned step can tolerate temperature upto ____________. Select the correct option according to the blanks.

Options

A. `95^(@) C, 60^(@)C`
B. `94^(@)C, 95^(@)C`
C. `72^(@)C, 95^(@)C`
D. `95^(@)C , 72^(@)C`

Answer

To answer the question regarding the optimum temperature for polymerization in PCR and the temperature tolerance of the enzyme responsible for this step, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding PCR**:
- PCR stands for Polymerase Chain Reaction, a technique used to amplify DNA, creating millions of copies from a small sample.

2. **Identifying the Steps of PCR**:
- PCR involves three main steps:
- **Denaturation**: The DNA strands are separated at a high temperature (around 94°C).
- **Annealing**: Primers bind to the single-stranded DNA (temperature varies between 48°C to 65°C).
- **Extension/Polymerization**: New DNA strands are synthesized.

3. **Finding the Optimum Temperature for Polymerization**:
- The optimum temperature for the polymerization (or extension) step in PCR is typically **72°C**. This is the temperature at which the DNA polymerase enzyme synthesizes new DNA strands effectively.

4. **Identifying the Enzyme Used**:
- The enzyme commonly used in PCR for polymerization is **Taq DNA polymerase**. This enzyme is thermostable, meaning it can withstand high temperatures without denaturing.

5. **Determining Temperature Tolerance of the Enzyme**:
- Taq DNA polymerase can tolerate temperatures up to approximately **95°C**. This is slightly higher than the denaturation temperature (94°C) to ensure the enzyme remains functional during the PCR process.

6. **Final Answer**:
- Therefore, the optimum temperature for polymerization in PCR is **72°C**, while the enzyme responsible for this step (Taq DNA polymerase) can tolerate temperatures up to **95°C**.

### Summary:
- The blanks can be filled as follows:
- The optimum temperature for polymerization in PCR is **72°C** while the enzyme responsible for the mentioned step can tolerate temperatures up to **95°C**.