PCR is used for

Options

A. Reverse transcribing RNA into DNA
B. Digesting DNA
C. Amplifying DNA
D. Amplifying proteins and separating DNA

Answer

**Step-by-Step Solution:**

1. **Understanding PCR**: PCR stands for Polymerase Chain Reaction. It is a technique used in molecular biology to amplify specific segments of DNA.

2. **Identifying the Purpose of PCR**: The primary purpose of PCR is to make multiple copies of a specific DNA sequence. This is crucial for various applications in genetics, forensics, and medical diagnostics.

3. **Evaluating the Options**:
- **Option 1: Reverse transcribing RNA into DNA**: This process involves converting RNA into complementary DNA (cDNA) using an enzyme called reverse transcriptase, which is not a function of PCR. Therefore, this option is incorrect.
- **Option 2: Digesting DNA**: This refers to the process of cutting DNA into smaller fragments using restriction enzymes. PCR does not involve breaking down DNA; it focuses on amplification. Thus, this option is also incorrect.
- **Option 3: Amplifying DNA**: This is the correct function of PCR. It involves making numerous copies of a specific DNA segment, which is the primary goal of the technique.
- **Option 4: Amplifying Proteins and Separating DNA**: While there are methods to amplify proteins, PCR specifically deals with DNA amplification, making this option incorrect as well.

4. **Conclusion**: The correct answer to the question "PCR is used for" is **Amplifying DNA**.

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