Dna Fingerprinting

Step 1: Role of PCR in DNA fingerprinting.
Polymerase Chain Reaction (PCR) is a technique used to amplify specific regions of DNA. This allows for the production of millions of copies of DNA fragments, which are then analyzed in DNA fingerprinting to identify genetic markers.

Step 2: Explanation of other techniques.
Gel Electrophoresis (Option B): Used to separate DNA fragments by size, but it does not amplify DNA.

DNA Sequencing (Option C): Determines the nucleotide sequence of DNA, not used for amplification in fingerprinting.

Southern Blotting (Option D): Detects specific DNA sequences but does not involve amplification.

Step 3: Conclusion.
PCR is the primary method for amplifying DNA regions in fingerprinting. \[ \therefore \text{The correct answer is: Polymerase Chain Reaction (PCR).