Which process creates many copies of a DNA segment?

• A. Cloning
• B. PCR
• C. Sanger Sequencing
• D. Amplification

Answer: (C)

When you need many copies of a specific DNA segment, PCR is the method designed for that. It uses cycles of denaturation, primer annealing, and extension with a DNA polymerase to copy the target region. Each cycle doubles the amount of the specific DNA, so after many cycles you get exponential amplification—enough material for analysis, cloning, or sequencing from a tiny starting sample. Sanger sequencing is a sequencing technique used to read the order of bases in a DNA fragment, not to generate large quantities of DNA. Cloning can produce multiple copies, but it requires inserting the fragment into a vector and growing in a host, which is slower and more involved. Amplification is the broad idea of increasing copy number, but the precise, rapid way to create many copies of a defined DNA segment in the lab is PCR.