Gene Expression and Regulation Question 7

The figure above depicts the DNA-protein complex that is assembled at the transcriptional start site of gene \(X\) when the expression of gene \(X\) is activated in liver cells. Previous studies have shown that gene \(X\) is never expressed in nerve cells. Based on the diagram, which of the following most likely contributes to the specific expression pattern of gene \(X\) ?

Expression of gene \(X\) produces large amounts of tRNA but undetectable amounts of mRNA.

The general transcription factors inhibit the activation of gene \(X\) in liver cells by blocking the activator from binding to RNA polymerase II.

The activator is a sequence-specific DNA-binding protein that is present in some tissues but not in other tissues.

The enhancer is a unique DNA segment that is added to the nuclear DNA of some cells of an organism during the process of mitotic cell division but not other cells.