A stomach cell is producing pepsin, an enzyme that hydrolyzes proteins. Which of the following events suggests that gene expression of pepsin has been turned off in the cell?
A) The pepsin protein is folded properly in the cytoplasm.
B) The chromosome with the pepsin gene is tightly coiled.
C) The pepsin mRNA leaves the nucleus and enters the cytoplasm.
D) Activators and RNA polymerases are abundant in the nucleus.

Question

Quizplus · Accepted Answer

If the chromosome with the pepsin gene is tightly coiled, it means that the DNA is in a condensed form which makes it inaccessible to the transcription machinery, and therefore, gene expression is turned off. The other options do not necessarily indicate that gene expression has been turned off.

A Stomach Cell Is Producing Pepsin, an Enzyme That Hydrolyzes