Final answer:
Operons in bacteria were discovered by Francois Jacob and Jacques Monod in the 1950s and 1960s, not the 1940s. They elucidated the regulatory mechanism of the lac operon in E. coli, for which they received the Nobel Prize in Medicine in 1965.
Step-by-step explanation:
The discovery of operons in bacteria can be attributed to the work of Francois Jacob and Jacques Monod in the 1950s and 1960s, not in the 1940s. The pivotal concept they introduced was the lac operon, a cluster of genes involved in lactose metabolism in E. coli. Their research demonstrated how the expression of genes in the operon could be turned on or off in response to the presence or absence of lactose.
This finding was crucial in understanding the regulatory mechanisms governing gene expression in prokaryotic organisms. For their groundbreaking work, Jacob, Monod, and their colleague Andre Lwoff were awarded the Nobel Prize in Medicine in 1965. Their research paved the way for modern genetic and molecular biology studies.
It is important not to confuse the work done on operons with other key genetic discoveries around the same period, such as the 'one gene-one enzyme' hypothesis by George Beadle and Edward Tatum or the demonstration of DNA as the genetic material by researchers like Avery, McLeod, McCarty, and later by Hershey and Chase.