Glucagon is a hormone that is released when the level of glucose in the blood is low. Glucagon uses a G protein signaling pathway to promote glycogenolysis. a. True
b. False

True.

Explanation:

It is true because glucagon is a peptide hormone that is secreted by the pancreas alpha cells.

This hormone is normally secreted when the blood glucose is low and this hormone make the liver to convert the glycogen that has been stored into Glu ise which is then released into the blood stream. It's play a vital role in regulating the blood glucose and it uses G protein signaling pathway to promote glycogenolysis and glycogenolysis is the process why glycogen is breakdown to glucose.