A mutation occurs in the promoter of a protein-encoding gene.How might this mutation affect the production of the protein encoded by the gene?
A) The mRNA made from this gene would exhibit the same mutation and therefore would not fold or function properly.
B) The protein made from the promoter would have a different amino acid sequence and therefore would not function properly.
C) The promoter might not be recognized by RNA polymerase, so the enzyme would be unable to attach to the promoter and start transcription.
D) The start codon would be missing from the mRNA made from this gene, so the mRNA could not be translated.

Question

Quizplus · Accepted Answer

A mutation in the promoter sequence of a gene can affect the ability of RNA polymerase to bind to the promoter and initiate transcription. This can result in reduced or altered production of the protein encoded by the gene. If the promoter is not recognized by RNA polymerase, then transcription will not occur, and the mRNA and protein will not be produced. Option A is incorrect because even if the mRNA undergoes mutation, it may still fold and function properly. Option B is incorrect because a mutation in the promoter would affect transcription, not translation. Option D is incorrect because the start codon is typically located within the coding sequence of the gene, not the promoter.

A Mutation Occurs in the Promoter of a Protein-Encoding Gene