A scientist uses materials in her lab to turn one piece of DNA into 100 copies of the same piece. What process is the scientist using?

Polymerase Chain Reaction (PCR)

Explanation:

Polymerase chain reaction (PCR) is a technique that creates thousands of copies of a small amount of DNA. The processes use a small amount of DNA at the template, Taq polymerase as enzyme of DNA replication, primers, and deoxyribonucleotides.

By the end of one round of PCR, two copies of one DNA fragment is formed. These two copies enter the second round of PCR and form a total of four DNA segments. The process goes on and creates the desired number of copies from the single piece of DNA.