Substance A is secreted by the liver, travels through the circulatory system bound to a carrier protein and causes a

change in gene expression in its target cell. Substance A is therefore a ligand for ____.



a. a receptor tyrosine kinase
b. a G-protein-coupled receptor
c. a steroid hormone receptor
d. a ligand-gated ion channel
e. guanylyl cyclase


ANSWER: c

Biology & Microbiology

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