Beadle and tatum's concept of the gene has been further refined to state which of the following most correct and current idea?
a. one gene - one enzyme
b. one gene - one polysaccharide
c. one gene - one metabolic block
d. one gene - one allele

a. one gene - one enzyme

Explanation:

Genes are connected to enzymes was first suggested by Sir Archibald Garrod. Later on, Beadle and Tatum carried out genetic studies on Neurospora and confirmed Garrod's hypothesis.

The link between genes and enzymes was called “one gene-one enzyme hypothesis”.

But this hypothesis is not accurate and changed because some proteins are encoded by genes are not enzymes. Some genes do not encode a whole protein but a subunit of a protein. In general, one polypeptide (a chain of amino acids) encoded by one gene.