Final answer:
The original "one enzyme" hypothesis stated that each gene controls the production of one enzyme.
Step-by-step explanation:
The original "one enzyme" hypothesis stated that each gene controls the production of one enzyme. This hypothesis was proposed by George Beadle and Edward Tatum in 1941 based on their studies in Neurospora crassa. They observed that mutations in genes resulted in deficiencies of specific enzymes, demonstrating a direct link between genes and enzymes.