The 'one gene - one polypeptide' concept was proposed by

1. Beadle and Tatum's experiments on Neurospora mutants linked specific gene mutations to loss of specific enzymes. 2. They originally framed it as 'one gene - one enzyme'. 3. It was later refined to 'one gene - one polypeptide' to include subunits. _Source: Maharashtra Balbharati Std XII Biology, Ch 4 "Molecular Basis of Inheritance" §4.7_