Final answer:
The enzyme reverse transcriptase was discovered by Howard Temin and David Baltimore. This enzyme is pivotal in enabling retroviruses to convert single-stranded RNA into double-stranded DNA, which is used in molecular biology and genetic engineering.
Step-by-step explanation:
The enzyme reverse transcriptase was discovered by Howard Temin and David Baltimore independently. This enzyme is crucial in the process where reverse transcriptase converts single-stranded RNA into double-stranded DNA, particularly in retroviruses. This discovery was a significant breakthrough because it helped to understand how viruses like HIV operate, as the enzyme allows the virus to insert its genetic material into the host cell's DNA, violating the central dogma of molecular biology that typically involves DNA making RNA, which then makes protein.
Reverse transcriptase is now widely used in molecular biology and genetic engineering as a tool to create complementary DNA (cDNA) from an RNA template. This tool has paved the way for numerous scientific advancements, including the development of various technologies for research and medicine.