The statement that "the functions of an organism are performed by different parts of its body" describes the concept of division of labor in biology. This principle is fundamental to the organization of complex organisms and can be observed at various levels, from cells to organ systems.

Here's a breakdown of what this means:

* Specialized Structures: Instead of every part of the body doing everything, different parts are specialized to perform specific tasks. For example, muscles are designed for movement, the lungs are for respiration, and the brain is for processing information.

* Interdependence: These specialized parts work together in a coordinated way. They rely on each other to function properly and maintain the overall well-being of the organism. For example, the digestive system breaks down food, the circulatory system transports nutrients, and the respiratory system provides oxygen - all necessary for the brain to function.

* Increased Efficiency: This division of labor allows organisms to be more efficient in their activities. By focusing on a specific task, each part can become highly specialized and perform its function more effectively.

In simpler terms: Imagine a team of workers building a house. Each worker has a specific skill - some are electricians, some are plumbers, some are carpenters. This division of labor allows them to build the house faster and more efficiently than if everyone tried to do everything. Similarly, in living organisms, different parts work together to keep the organism alive and functioning.