Final answer:
RT-PCR is highly sensitive due to the use of reverse transcriptase to convert RNA into cDNA for subsequent PCR amplification, making it effective in detecting RNA viruses.
Step-by-step explanation:
The sensitivity of reverse transcriptase PCR (RT-PCR) is attributed to its ability to detect and amplify RNA sequences by initially converting them into complementary DNA (cDNA) using the enzyme reverse transcriptase. This makes it particularly useful in detecting RNA viruses, by first creating a cDNA strand from the viral RNA, and then amplifying that cDNA through traditional PCR methods to a sufficient quantity for detection. The presence of reverse transcriptase is crucial for this process as it allows the initial creation of cDNA from an RNA template, which is then exponentially amplified by PCR.