Question

what is the role of insulin in maintaining homeostasis?
○ tells cells to take glucose out of the blood, decreasing levels.
○ keeps glucose in the blood, increasing levels.
○ stores the glucose as fat, increasing levels.
○ tells the kidneys to excrete the glucose, decreasing levels.

Explanation:

Insulin is a hormone that regulates blood glucose. Its main role is to signal cells (like muscle, fat, liver cells) to absorb glucose from the blood, which lowers blood glucose levels to maintain homeostasis. The second option is wrong as insulin reduces, not increases, blood glucose. The third is wrong because while insulin can promote fat storage from excess glucose, its primary acute role for homeostasis is glucose uptake by cells (not just storing as fat to increase levels). The fourth is wrong as kidneys excreting glucose is not insulin’s role (insulin doesn’t act on kidneys to excrete glucose; in diabetes, when insulin is insufficient, kidneys may excrete glucose, but that’s a pathology, not insulin’s normal function).

Answer:

A. Tells cells to take glucose out of the blood, decreasing levels.