The polymerase chain reaction

Options

A. quickly amplifies the small samples of DNA
B. is involved in the production of transgenic organisms
C. is used to make literally billions of copies in only a few hours
D. starts with one gene sized piece of RNA

Answer

**Step-by-Step Text Solution:**

1. **Definition of Polymerase Chain Reaction (PCR)**:
- The Polymerase Chain Reaction (PCR) is a molecular biology technique used to amplify specific segments of DNA, producing millions of copies from a small initial sample.

2. **Purpose of PCR**:
- The primary purpose of PCR is to generate multiple copies (clones) of a specific DNA sequence or gene of interest. This is essential for various applications in genetics, forensics, and molecular biology.

3. **Steps Involved in PCR**:
- **Denaturation**: The first step involves heating the DNA sample to separate the two strands, resulting in single-stranded DNA.
- **Annealing**: In this step, short DNA sequences called primers bind (anneal) to the single-stranded DNA at specific locations. These primers are essential for initiating the synthesis of new DNA strands.
- **Extension (Elongation)**: The final step involves the enzyme DNA polymerase extending the primers to form new strands of DNA, effectively doubling the amount of DNA with each cycle.

4. **Efficiency of PCR**:
- PCR can amplify DNA quickly, allowing for billions of copies to be made in a relatively short time (though not literally in just a few hours as some statements might suggest).

5. **Common Misconceptions**:
- PCR does not start with RNA; it begins with DNA. Therefore, any statement suggesting that PCR starts with a piece of RNA is incorrect.
- While PCR is a crucial technique in creating transgenic organisms, it is not directly responsible for the production of transgenic organisms; that involves other processes like recombinant DNA technology.