A group of organs that work together to perform complex functions for the body.

• A. Organ
• B. Organ System
• C. Tissue
• D. Cell

Answer: (B)

Think of how the body handles big tasks that require several parts working in harmony. The body is organized in levels: cells form tissues, tissues form organs, and when several organs collaborate to achieve a larger function, they make up an organ system. An organ system is a group of multiple organs that coordinate to perform complex processes like digestion, circulation, or breathing. For example, the digestive system includes the stomach, intestines, liver, and pancreas working together to break down food and absorb nutrients; the circulatory system moves blood, nutrients, and wastes throughout the body. This description fits an organ system exactly, because it emphasizes multiple organs acting together to accomplish a complex job. An organ is a single structure made of tissues; a tissue is made of similar cells; a cell is the basic unit of life.