Question

One gene one enzyme hypothesis was postulated by

• A. De Vries (1909)
• B. Beadle and Tautam (1941)
• C. Beadle and Tautam (1940)
• D. Avery and coworkers (1944)

Hint:

The mold Neurospora crassa is often called the "Drosophila of the fungi" because of its role in these genetic breakthroughs.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The "one gene-one enzyme" hypothesis is a foundational principle of biochemical genetics.
It explains the link between genes (inherited information) and the chemical reactions (metabolism) that occur within an organism.
Detailed Explanation:
This hypothesis was proposed by George Beadle and Edward Tatum based on their experiments with the red bread mold, Neurospora crassa.
They used X-rays to induce mutations in the mold.
They discovered that some of the mutated strains could no longer grow on simple media because they had lost the ability to synthesize specific essential nutrients (like amino acids).
By systematically testing these mutants, they showed that each mutation resulted in the failure of a specific step in a metabolic pathway.
They concluded that a specific gene is responsible for the production of a specific enzyme that catalyzes a specific reaction.
Their findings were published in 1941.
Later, this theory was refined to "one gene-one polypeptide," as some proteins are made of multiple subunits encoded by different genes, and not all gene products are enzymes.
Beadle and Tatum shared the Nobel Prize in 1958 for this revolutionary work.

Step 2: Final Answer:
The hypothesis was postulated by Beadle and Tatum in 1941.