Question

1. which statement best describes the role of insulin in the body?

a insulin acts like a key to help glucose (sugar) move out of cells and into the bloodstream.
b insulin acts like a key to help glucose (sugar) move out of the blood stream and into the cells.
c insulin builds up in the blood and causes high blood sugar.
d insulin causes damage to large blood vessels.

Explanation:

Insulin is a hormone produced by the pancreas. Its main role is to regulate blood - glucose levels. When blood glucose levels rise (e.g., after a meal), the pancreas releases insulin. Insulin binds to receptors on cells (such as muscle, fat, and liver cells). This binding acts like a "key" that unlocks the cells, allowing glucose to move from the bloodstream (where it is in high concentration) into the cells (where it can be used for energy production, stored as glycogen in the liver and muscle, or converted to fat for long - term storage).

• Option A is incorrect because insulin helps glucose move into cells, not out of cells and into the bloodstream.
• Option C is incorrect. High blood sugar (hyperglycemia) is often due to a lack of insulin (type 1 diabetes) or the body's inability to respond properly to insulin (type 2 diabetes), not because insulin builds up in the blood. In fact, in type 2 diabetes, there can be initially high levels of insulin due to the body's attempt to compensate for insulin resistance.
• Option D is incorrect. Insulin itself does not cause damage to large blood vessels. Chronic high blood sugar (due to problems with insulin action or production) can lead to damage of blood vessels over time through processes like glycation of proteins in the vessel walls.

Answer:

B. Insulin acts like a key to help glucose (sugar) move out of the blood stream and into the cells.