Polymerase chain reaction is useful in

Options

A. Locating simple sequence repeats
B. Locating variable number of tandem repeats
C. Developing restriction maps
D. Amplification of gene of interest

Answer

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

1. **Understanding PCR**: The Polymerase Chain Reaction (PCR) is a technique used to amplify a specific segment of DNA, creating millions of copies of a particular gene of interest. This method was developed by Carey Mullis, who won a Nobel Prize for his work.

2. **Applications of PCR**: PCR is widely used in various fields, including:
- **Gene Cloning**: PCR allows for the amplification of genes so that they can be cloned into vectors for further study or manipulation.
- **Diagnosis of Diseases**: PCR can detect the presence of specific pathogens in a sample, making it useful in medical diagnostics.
- **Forensic Science**: PCR is used to amplify DNA from crime scenes for identification purposes.
- **Research**: It is used in various research applications to study genes and their functions.

3. **Steps of PCR**:
- **Denaturation**: The double-stranded DNA is heated to separate it into two single strands.
- **Annealing**: Short DNA primers bind to the single-stranded DNA at specific locations.
- **Extension**: The enzyme Taq polymerase synthesizes new DNA strands by adding nucleotides to the primers.

4. **Importance of Taq Polymerase**: Taq polymerase is a thermostable enzyme derived from the bacterium Thermus aquaticus, which allows the PCR process to withstand high temperatures (around 94-95°C) necessary for denaturation.

5. **Conclusion**: The primary utility of PCR is the amplification of a gene of interest, which can then be used in various applications such as gene cloning, diagnosis, and research.

**Final Answer**: Polymerase chain reaction (PCR) is useful in amplifying genes for gene cloning, diagnostics, forensic science, and research applications.

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