Final answer:
The genes amplified in the PCR reaction with the plant master mix are those targeted by specific primers chosen for their relevance to the study, such as markers or genes of interest in transgenic plants.
Step-by-step explanation:
The genes amplified in the PCR reaction with the plant master mix are specific to the primers used. In the context of studying transgenic plants, primers are designed to bind to sequences that flank a gene of interest or a genetic marker in the plant's genome. An example given is the use of primers targeting the Ubi promoter and TaBWPR-1.2 sequences. These genes or markers are selected based on their relevance to the research study, such as confirming the presence of transgenes or assessing gene expression in different tissues.
PCR allows for the amplification of these specific segments of DNA, generating millions of copies from a minimal starting quantity. Researchers can then visualize the PCR product using agarose gel electrophoresis stained with ethidium bromide, confirming the successful amplification of the desired DNA fragments.