Which system delivers nutrients and removes waste from cells?

• A. Delivers nutrients and removes waste
• B. Endocrine system
• C. Immune system
• D. Muscular system

Answer: (A)

The circulatory system is responsible for delivering nutrients to cells and removing waste from them. Blood carries nutrients absorbed from the digestive system to every cell in the body, and it also picks up waste products like carbon dioxide to be expelled by the lungs or processed by the kidneys and liver. The heart pumps blood through a network of vessels, ensuring nutrients reach tissues and wastes are carried away. Other systems do important jobs—endocrine regulates processes via hormones, the immune system defends against pathogens, and the muscular system enables movement—but they aren’t the primary transport system for nutrients and cellular waste.