Base your answer to the following question on Which statement best expresses the information represented in the graph shown below?

Answer Explanation

C) villi

- Correct: The absorptive surface of the small intestine is greatly increased due to the presence of villi. Villi are finger-like projections that line the inner surface of the small intestine. These structures greatly increase the surface area available for absorption. Each villus contains capillaries and lacteals (lymphatic vessels) that absorb nutrients from digested food. The large surface area provided by the villi allows for more efficient absorption of nutrients such as carbohydrates, proteins, fats, vitamins, and minerals.

A) alveoli

- Incorrect: Alveoli are tiny air sacs in the lungs where gas exchange occurs during respiration. They are not found in the digestive system and do not contribute to the absorptive surface of the small intestine.

B) neurons

- Incorrect: Neurons are nerve cells that transmit signals throughout the body, including the digestive system. While neurons play a role in regulating digestion and other digestive processes, they do not directly contribute to the absorptive surface of the small intestine.

D) nephrons

- Incorrect: Nephrons are the functional units of the kidneys responsible for filtering blood and producing urine. They are not part of the digestive system and do not contribute to the absorptive surface of the small intestine.

Answer Explanation

The digestive system provides materials in the form of nutrients from food, such as carbohydrates, fats, and proteins. These nutrients are broken down during digestion and absorbed into the bloodstream.

The respiratory system provides oxygen, which is necessary for cellular respiration, the process by which ATP (adenosine triphosphate) is produced in cells. Oxygen is inhaled into the lungs and diffuses into the bloodstream to be transported to cells throughout the body.

Answer Explanation

C) polysaccharide that is synthesized and stored within the human liver

- Correct: Glycogen is a polysaccharide, which means it is a complex carbohydrate composed of many glucose molecules linked together. It is synthesized and stored primarily in the liver and muscles of humans and other vertebrates. Glycogen serves as a form of energy storage, allowing organisms to store glucose for later use when energy demands are high or when glucose availability is low.

A) complex carbohydrate that is often stored in red blood cells

- Incorrect: While glycogen is a complex carbohydrate, it is not stored in red blood cells. Red blood cells do not contain nuclei or organelles, including glycogen storage structures.

B) complete protein necessary for the synthesis of cell membranes

- Incorrect: Glycogen is not a protein. It is a carbohydrate used for energy storage. Proteins are composed of amino acids and are involved in various cellular functions, including the synthesis of cell membranes, but glycogen does not play a direct role in this process.

D) by-product of sucrose digestion within the pancreas

- Incorrect: Glycogen is not a by-product of sucrose digestion within the pancreas. Sucrose is a disaccharide composed of glucose and fructose, and it is broken down into its component sugars by enzymes in the small intestine, not the pancreas. Glycogen is synthesized and stored in the liver and muscles as a form of energy storage.