What is the main function of polymerase chain reaction (PCR)?

The main function of polymerase chain reaction (PCR) is to replicate and amplify a specific gene sequence. This technique is fundamental in molecular biology because it enables scientists and researchers to produce millions of copies of a particular DNA segment from a small initial sample. By doing so, PCR makes it easier to analyze the DNA for various applications, such as sequencing, cloning, or detecting genetic disorders.

PCR operates through a series of temperature cycles that denature the DNA, anneal primers to the target sequence, and extend the new DNA strands. The end result is a substantial increase in the amount of the target DNA, which is crucial when working with limited quantities of biological material.

In contrast, the other options highlight different molecular biology techniques and functions that do not describe PCR's main purpose. For example, while detecting gene duplication and deletions is essential in genetics and can involve other methods, it is not the primary function of PCR. Similarly, cutting DNA with restriction enzymes and finding specific gene parts using probes are techniques used in cloning and hybridization, respectively, which are not directly related to PCR's function of amplification.