A researcher is studying a lipid hormone that can bind to both intracellular and extracellular receptors. What implications does this have for signal transduction and cellular responses?

• A. The hormone will only affect metabolic responses and not gene expression.
• B. The hormone cannot diffuse through the plasma membrane.
• C. The hormone can only affect gene expression by binding to nuclear receptors.
• D. The hormone can initiate signal transduction pathways by binding to extracellular receptors and directly affect gene expression by binding to intracellular receptors.

Answer: (D)