Question

Palaeontologists unearthed a human skull during excavation. A small fragment of the scalp tissue was still attached to it. Only a little 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 by

• 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 endonucleases

Answer 1

The correct option is B subjecting the DNA to polymerase chain reaction

Polymerase Chain Reaction (PCR) is a technique by which small samples of DNA can be amplified. Starting with a very small piece of DNA, this technique is used to make literally billions of copies in only a few hours. So even if little DNA could be extracted from the human skull, using PCR we can amplify it and then this can be used to analyse ancient man.
Hybridising the DNA with a DNA probe - Probe helps us to identify a particular gene sequence in a DNA sample.
Subjecting the DNA to gel electrophoresis - is a technique used to separate DNA fragments based on their size and charge.
Treating the DNA with restriction endonucleases - restriction enzymes locate specific sequences of DNA and cleave them.