The polymerase chain reaction is a technique used for
1) amplification of DNA
2) amplification of enzymes
3) amplification of proteins
4) all of these

Options

A. 1) amplification of DNA
B. 2) amplification of enzymes
C. 3) amplification of proteins
D. 4) all of these

Explanation

**Step-by-Step Solution:**

1. **Understanding PCR**: The Polymerase Chain Reaction (PCR) is a widely used technique in molecular biology. Its primary function is to amplify specific segments of DNA, making millions of copies of a particular DNA sequence.

2. **Identifying the Purpose of PCR**: The question asks what PCR is used for. The options provided are:
- 1) Amplification of DNA
- 2) Amplification of enzymes
- 3) Amplification of proteins
- 4) All of these

3. **Analyzing Each Option**:
- **Option 1**: Amplification of DNA is the primary function of PCR. This is achieved through a series of steps: denaturation, annealing, and extension.
- **Option 2**: Amplification of enzymes is incorrect because PCR specifically amplifies DNA, not enzymes. Enzymes are proteins and cannot be amplified using PCR.
- **Option 3**: Amplification of proteins is also incorrect for the same reason as option 2. PCR does not amplify proteins.
- **Option 4**: This option is incorrect since it suggests that PCR can amplify enzymes and proteins, which it cannot.

4. **Conclusion**: Based on the analysis, the only correct answer is option 1, which states that PCR is used for the amplification of DNA.

**Final Answer**: The correct option is **1) amplification of DNA**.

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