A scientist compares the promoter regions of two genes. Gene A’s core promoter plus proximal promoter elements encompass 70bp. Gene B’s core promoter plus proximal promoter elements encompass 250bp. Which of the scientist’s hypotheses is most likely to be correct?

a. More transcripts will be made from Gene B.

b. Transcription of Gene A involves fewer transcription factors.

c. Enhancers control Gene B’s transcription.

d. Transcription of Gene A is more controlled than the transcription of Gene B.

The organisation of genes facilitates the control of gene expression. The coding sequence is immediately upstream of the promoter region. This area can be quite long or only a few nucleotides long (hundreds of nucleotides long). The more area there is for proteins to bind, the longer the promoter.

Fewer transcription factors are required for the transcription of Gene A. Because these additional sites are typically located a few hundred base pairs or less upstream of the transcriptional start site, Some biologists prefer to categorise these extra sites as promoter-proximal elements and limit the extent of the eukaryotic promoter to the core promoter, or polymerase binding site.

As the answer is of factual nature, the rest of the options are irrelevant.