The Beadle and Tatum experiments were based on all of the following assumptions except that. A. supplemented media permit growth of auxotrophic strains of Nourospora
B. X-irradiation can induce mutations.
C. two strains of auxotrophic Nourospora that grow on minimal medium supplemented with biotin have mutations in the same gene
D. auxotrophs fail to grow on minimal media In their first round of screening. Boodle and Tatum plated spores on minimal medium

C. two strains of auxotrophic Nourospora that grow on minimal medium supplemented with biotin have mutations in the same gene

Explanation: The Beadle and Tatum experiments had the exception that two strains of auxotrophic Nourospora that grow on minimal medium supplemented with biotin have mutations in the same gene. Thus they played a role in confirming the one gene, one enzyme hypothesis which is the idea that each gene encodes a single enzyme.

While correct but not exact, the hypothesis was confirmed through the use of genetic and biochemical studies of the bread mould Neurospora which were unable to make specific amino acids when mutated as a consequence of a "broken" enzyme needed to build a certain amino acid.

the dark variety, as they are not visible on the dark tree barks

explanation: