The whole cycle of gene amplification requires

Options

A. 5 minutes
B. 30 minutes
C. 3 hours
D. 24 hours.

Answer

To solve the question regarding the time required for the whole cycle of gene amplification, we can break down the process of Polymerase Chain Reaction (PCR) into its key stages:

### Step-by-Step Solution:

1. **Understanding PCR**:
- PCR (Polymerase Chain Reaction) is a technique used to amplify specific segments of DNA. It involves repeated cycles of heating and cooling to denature DNA, anneal primers, and extend the DNA strands.

2. **Denaturation Stage**:
- The first step in PCR is denaturation, where the double-stranded DNA is heated to separate it into two single strands. This stage typically takes about **1 to 2 minutes**.

3. **Annealing Stage**:
- After denaturation, the temperature is lowered to allow short oligonucleotide primers to bind (anneal) to their complementary sequences on the single-stranded DNA. This stage lasts about **30 seconds**.

4. **Extension Stage**:
- Following annealing, the temperature is raised again to allow the DNA polymerase to extend the primers and synthesize new DNA strands. This stage usually takes about **1 to 2 minutes** as well.

5. **Total Time Calculation**:
- If we consider a typical PCR cycle, it consists of:
- Denaturation: 1-2 minutes
- Annealing: 0.5 minutes (30 seconds)
- Extension: 1-2 minutes
- Adding these times together gives us approximately **3 to 5 minutes** for one cycle.

6. **Multiple Cycles**:
- PCR typically involves **20-40 cycles** to achieve significant amplification. However, the question asks for the time required for a single cycle.

7. **Conclusion**:
- Since the question refers to the whole cycle of gene amplification, and considering the time for multiple cycles, the total time for a complete PCR process is generally around **30 minutes** when accounting for setup and multiple cycles.

### Final Answer:
The whole cycle of gene amplification requires approximately **30 minutes**.

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