Final answer:
PCR primarily allows for the amplification of DNA to detect the presence of a targeted gene, with variations like qPCR quantifying gene concentrations and RT-PCR detecting gene expression.
Step-by-step explanation:
PCR and Its End Results
The end result of traditional PCR (Polymerase Chain Reaction) allows for the amplification of DNA sequences. Specifically, it can show the absence or presence of a targeted gene. However, it does not inherently quantify genes or proteins, nor does it produce an RNA product. For quantifying the amount of a specific gene, quantitative PCR (qPCR) is used, which employs fluorescence to monitor the amplification in real-time and estimate the concentration of the initial DNA. RT-PCR (reverse transcriptase PCR) begins with reverse transcriptase converting mRNA into cDNA, which is then amplified, allowing for the detection of gene expression.