A nonsense mutation halts protein synthesis by creating a stop codon, such as ATT (UAA), ATC (UAG), or ACT (UGA). In the lac operon of Escherichia coli, which includes structural genes z, y, and a, if the y gene results in a stop codon, only the z gene product, β-galactosidase, will be syn

Question

A nonsense mutation halts protein synthesis by creating a stop codon, such as ATT (UAA), ATC (UAG), or ACT (UGA). In the lac operon of Escherichia coli, which includes structural genes z, y, and a, if the y gene results in a stop codon, only the z gene product, β-galactosidase, will be synthesized.

Accepted Answer

Correct. A nonsense mutation in the 'y' gene of the lac operon would result in premature termination of its polypeptide synthesis. However, the 'z' gene, which is upstream, would still transcribe and translate into β-galactosidase as it is unaffected by the mutation.

A nonsense mutation halts protein synthesis by creating a stop codon, such as ATT (UAA), ATC (UAG), or ACT (UGA). In the lac operon of Escherichia coli, which includes structural genes z, y, and a, if the y gene results in a stop codon, only the z gene product, β-galactosidase, will be synthesized.

Solution

Related NEET Biology questions