ASIS International (ASIS) Professional Certified Investigator Practice Exam

What is the primary purpose of PCR in genetic analysis?

1. Chemically replicates DNA

2. Positively identifies genetic markers

3. Uses chemicals and radiation to mark genes

4. Identifies differences in DNA

The correct answer is: Chemically replicates DNA

The primary purpose of Polymerase Chain Reaction (PCR) in genetic analysis is to chemically replicate DNA. This technique amplifies small segments of DNA, making millions of copies from just a few templates. This replication is crucial for various applications in genetic analysis, such as cloning, gene expression analysis, and forensic investigations, because it allows researchers to work with sufficient quantities of DNA for further study. The process involves using specific primers that are designed to bind to the target DNA sequence, along with DNA polymerase and nucleotides, to facilitate the synthesis of new DNA strands. The other options do not encapsulate the main function of PCR. While positively identifying genetic markers and identifying differences in DNA are important aspects of genetic analysis that can be enhanced by PCR, the core function remains the amplification of DNA sequences. Similarly, while marking genes might involve the use of various techniques, PCR itself does not focus on marking but rather on increasing the amount of DNA available for analysis.