What level of organization includes organs and organ systems?

The level of organization that includes organs and organ systems is best represented by the term "organ systems." Organ systems are composed of multiple organs that work together to perform complex functions necessary for the survival and proper functioning of an organism. For example, the digestive system includes organs such as the stomach, intestines, liver, and pancreas, all collaborating to process food and absorb nutrients.

This level of biological organization encapsulates the integration and cooperation of various organs, each with its specialized roles, to ensure overall system efficacy. While "organisms" refers to complete living entities, and "tissues" refers to groups of similar cells working together, organ systems stand out because they reflect a higher organizational complexity, where multiple organs interact to maintain the health and functionality of the organism.