試題詳解

9. The insulin gene is transcriptionally expressed in certain pancreatic cells, but not in skin cells. Which statement best explains this?
(A) Pancreas cells express an activator protein that binds the insulin enhancer.
(B) Pancreas cells have more enhancers in the insulin gene.
(C) The insulin genes in pancreatic cells and skin cells have different promoters and, therefore, they respond to different regulatory proteins.
(D) Skin cells lack an enhancer in the insulin gene.
(E) Skin cells lack the insulin gene.