1. A ligand binding to which type of receptor triggers multiple transduction pathways at once?

A.
ligand-gated ion channel

B.
intracellular receptor

C.
receptor tyrosine kinase

D.
G protein-coupled receptor


2.. The gene MC1R codes for a G protein-coupled receptor called melanocortin 1 that is involved in producing one of two types of melanin that determines human hair color. Eumelanin produces dark-colored hair, while pheomelanin produces light-colored hair. When the receptor is active, eumelanin is produced. Hypothesize what would happen if this receptor were blocked or deactivated.

A.
Eumelanin production would not change.

B.
Pheomelanin production would increase.

C.
Pheomelanin production would decrease.

D.
Eumelanin production would increase.