Beadle & Tatum concluded that one gene carries the directions for making one protein, in which year was this conclusion proposed?

Beadle & Tatum concluded that one gene carries the directions for making one protein, in which year was this conclusion proposed?

• A. One gene carries the directions for making one protein, proposed in 1935
• B. One gene carries the directions for making one protein, proposed in 1941
• C. One gene encodes RNA, proposed in 1953
• D. One gene is unrelated to protein synthesis, proposed in 1928

Answer: (B)

Beadle and Tatum tested the idea that a gene directs the production of a specific enzyme. Through experiments with Neurospora crassa, they mutagenized strains and found mutants that could not synthesize particular nutrients unless that step’s enzyme activity was supplied. Each mutation affected a single enzymatic step, leading them to conclude that one gene carries the directions for making one enzyme, i.e., one gene-one enzyme. This conclusion was proposed in 1941. (Later refinements note that some proteins are composed of multiple polypeptides, so the broader idea is often stated as one gene-one polypeptide.)

Beadle and Tatum tested the idea that a gene directs the production of a specific enzyme. Through experiments with Neurospora crassa, they mutagenized strains and found mutants that could not synthesize particular nutrients unless that step’s enzyme activity was supplied. Each mutation affected a single enzymatic step, leading them to conclude that one gene carries the directions for making one enzyme, i.e., one gene-one enzyme. This conclusion was proposed in 1941. (Later refinements note that some proteins are composed of multiple polypeptides, so the broader idea is often stated as one gene-one polypeptide.)