Beadle and Tatum's 'one-gene-one-protein' hypothesis was modified to the 'one-gene-one-polypeptide' hypothesis - HSC - SSCE Biology - Question 4 - 2016 - Paper 1

The modification from the 'one-gene-one-protein' hypothesis to the 'one-gene-one-polypeptide' hypothesis indicates that Beadle and Tatum recognized the complexity of gene function and protein synthesis. This change reflects an understanding that a single gene can code for multiple polypeptides, depending on the circumstances, which points to the provisional nature of their earlier conclusions. The modification suggests that their initial hypothesis was not absolute, hence making option (D) the correct answer: 'Their conclusions were provisional in nature.'