Answer:
a. Glucagon is released by the beta cells of the pancreatic islets of Langerhans.
Explanation:
When the body is fasting, the pancreas releases glucagon so that your body can produce glucose. Glucagon is a protein hormone made and secreted by alpha cells from pancreatic islets (or islets of Langerhans).
The islets of Langerhans are a special group of cells in the pancreas that produce not only glucagon, but also insulin. These substances act as important regulators of sugar metabolism.
Inner core, outer core, mantle and crust
I think it is called mechanical digestion. Or alas, chemical digestion. One of those. Or both!
Hope helps-aparri
(thank yous are welcome)