In PCR tehnology the DNA segment is replicated over a billion times. This repeated replication is catalysed by the enzyme :

Options

A. DNA dependent RNA polymerase
B. DNA polymerase
C. Taq polymerase
D. Primase

Answer

**Step-by-Step Solution:**

1. **Understanding PCR Technology:**
- PCR stands for Polymerase Chain Reaction, a molecular biology technique used to amplify specific DNA segments.

2. **Identifying the Enzyme:**
- The question asks which enzyme catalyzes the repeated replication of DNA in PCR.

3. **Analyzing the Options:**
- The options provided are:
- DNA dependent RNA polymerase
- DNA polymerase
- Taq polymerase
- Primase

4. **Evaluating Each Option:**
- **DNA dependent RNA polymerase:** This enzyme synthesizes RNA from a DNA template and is not involved in DNA replication.
- **DNA polymerase:** While it is involved in DNA synthesis, it is typically not heat-stable and can denature at the high temperatures used in PCR.
- **Taq polymerase:** This is a heat-stable DNA polymerase derived from the thermophilic bacterium *Thermus aquaticus*. It can withstand the high temperatures required during PCR without losing its activity.
- **Primase:** This enzyme synthesizes RNA primers necessary for DNA replication but is not the main enzyme used in PCR for amplifying DNA.

5. **Conclusion:**
- The enzyme that catalyzes the repeated replication of DNA in PCR technology is **Taq polymerase**.

**Final Answer: Taq polymerase**

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