Palaeontologists unearthed a human skull during excavation. A small fragment of the scalp tissue was still attached to it. Only Iittle DNA could be extracted from it. If the genes of the ancient man need to be analysed, the best way of getting sufficient amount of DNA from this extract is

Options

A. Hybridising the DNA with a DNA probe
B. Subjecting the DNA to polymerase chain reaction
C. Subjecting the DNA to gel electrophoresis
D. Treating the DNA with restriction endonuclease

Answer

To analyze the genes of the ancient man from the small fragment of scalp tissue, we need to obtain a sufficient amount of DNA. The best method for this is the Polymerase Chain Reaction (PCR). Here’s a step-by-step explanation of the process:

### Step-by-Step Solution:

1. **Understanding the Situation**:
- A human skull with a small fragment of scalp tissue has been unearthed.
- Only a limited amount of DNA can be extracted from this tissue.

2. **Identifying the Need**:
- To analyze the genes of the ancient man, we need to amplify the small amount of DNA extracted from the scalp tissue.

3. **Choosing the Right Technique**:
- Among the options provided:
- A. Hybridizing the DNA with a DNA probe: This is used for detecting specific sequences but does not amplify DNA.
- B. Subjecting the DNA to Polymerase Chain Reaction (PCR): This technique amplifies DNA, making it suitable for analysis.
- C. Subjecting the DNA to gel electrophoresis: This is used for separating DNA fragments but does not amplify DNA.
- D. Treating the DNA with restriction endonuclease: This cuts DNA at specific sites but does not amplify it.

4. **Understanding PCR**:
- PCR is a technique that allows for the amplification of a specific DNA segment. It involves three main steps:
- **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**: DNA polymerase synthesizes new DNA strands by extending from the primers, resulting in the duplication of the target DNA.

5. **Conclusion**:
- Since PCR effectively amplifies the DNA, it is the best method to obtain a sufficient amount of DNA from the small extract for further analysis.

### Final Answer:
The best way to get a sufficient amount of DNA from the extract is by **subjecting the DNA to Polymerase Chain Reaction (PCR)**.

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