What is the primary purpose of PCR (Polymerase Chain Reaction)?

The primary purpose of PCR (Polymerase Chain Reaction) is to amplify specific DNA sequences for analysis. This technique enables researchers to take a small sample of DNA and make millions of copies of a particular region of interest, allowing for detailed study and analysis of that sequence. Amplification is essential in various applications, such as genetic research, forensic analysis, medical diagnostics, and more, because it increases the amount of DNA available for testing, facilitating easier detection and examination.

While the other options involve processes related to nucleic acids or proteins, they do not accurately describe the primary function of PCR. Modifying protein functions, determining nucleotide sequences, and extracting DNA all pertain to different techniques or methods used in molecular biology, but they do not encompass the main goal of PCR, which is specifically about creating multiple copies of a given DNA segment.