What is the digestive system?

Correct Answer: C

Rationale: The correct answer is C: The body's food-processing system. The digestive system is responsible for processing and breaking down food into nutrients that can be absorbed by the body. This process involves various organs such as the stomach, intestines, and liver. It is not the body's breathing system (A), nervous system (B), or blood-transporting system (D) because those systems have different functions and are not directly involved in food processing.

Correct Answer: B

Rationale: The correct answer is B: pepsin. Pepsin is a digestive enzyme that breaks down proteins into smaller peptides. In this demonstration, the decrease in mass of the meat from 10g to 3g suggests protein digestion occurred. Bile (A) emulsifies fats, maltose (C) breaks down carbohydrates, and amylase (D) also breaks down carbohydrates, so they wouldn't cause the observed mass change.

Correct Answer: C

Rationale: The correct answer is C: pepsin. Pepsin is an enzyme produced in the stomach that breaks down proteins into peptides. It functions in an acidic environment, which is characteristic of the stomach. Amylase (A) breaks down carbohydrates, lipase (B) breaks down fats, and trypsin (D) breaks down proteins in the small intestine, not in structure W.

Correct Answer: C

Rationale: Sure. Secretin is the correct answer as it specifically stimulates the release of pancreatic juice. Secretin is released from the duodenum in response to the acidic chyme entering from the stomach. It acts on the pancreas to increase the secretion of bicarbonate-rich pancreatic juice, which helps neutralize the acidic chyme. Insulin (choice A) regulates blood sugar levels, gastrin (choice B) stimulates gastric acid secretion, and glucagon (choice D) increases blood glucose levels. These hormones do not directly stimulate the release of pancreatic juice.

Correct Answer: C

Rationale: Rationale: Insulin facilitates the uptake of glucose from the bloodstream into body cells. When insulin is injected into a healthy person, it enhances glucose absorption by body cells, leading to an increase in glucose concentration within the cells. This process helps regulate blood glucose levels by promoting glucose utilization for energy production and storage. Therefore, choice C is correct. Summary: A: Blood glucose levels would not increase as insulin promotes glucose uptake into cells. B: The liver would not convert glycogen into glucose as a response to insulin injection. D: The cell membrane would not become less permeable to glucose; insulin increases glucose uptake by enhancing membrane transport proteins.