Question

Studies by Beadle and Tatum that produced the ‘one-gene one-enzyme hypothesis’ were conducted using the ______.

Options

• bread mold Neurospora crassa

• bacterium Streptococcus pneumoniae

• bacterium Escherichia coli

• mushroom Agaricus bisporus

Answer 1

Studies by Beadle and Tatum that produced the ‘one-gene one-enzyme hypothesis’ were conducted using the bread mold Neurospora crassa.

Explanation:

George Beadle and Edward Tatum conducted their Nobel Prize-winning experiments using the red bread mold, Neurospora crassa. They chose this organism because it was easy to grow and had a simple life cycle that allowed them to trace genetic changes directly. By exposing the mold to X-rays to induce mutations, they identified “auxotrophic” mutants that could no longer grow on a minimal nutrient medium. Their discovery that each mutation blocked a specific step in a metabolic pathway led to the “one gene-one enzyme” hypothesis, proving that genes act by regulating specific chemical events through the production of enzymes.