Final answer:
An increase in blood glucose levels triggers beta cells of the pancreas to release insulin, not glucagon. It's actually a decrease in glucose levels that stimulates the release of glucagon from the alpha cells to raise the glucose levels.
Step-by-step explanation:
The statement that an increase in blood glucose levels (and/or falling amino acid levels) stimulates alpha cells of the pancreatic islet to secrete glucagon is false. In fact, when blood glucose levels decrease, this triggers the alpha cells of the pancreas to release glucagon. Glucagon serves to increase blood glucose levels by promoting glycogenolysis and gluconeogenesis. Conversely, an increase in blood glucose levels prompts the beta cells to release insulin, which helps to lower the blood glucose levels by enhancing glucose uptake by cells and converting excess glucose into glycogen.