What level of organization includes organs and organ systems?

The correct answer pertains to the level of organization known as "organ systems," which encompasses both organs and the systems made up of them. In biological hierarchy, the organization begins with cells, which combine to form tissues. Tissues then work together to create organs, such as the heart or lungs. These organs are grouped into organ systems, which perform specific functions necessary for the survival of the organism. For instance, the cardiovascular system includes the heart, blood vessels, and blood, all working together to circulate blood throughout the body.

Understanding this hierarchy is crucial, as each level of organization plays a specific role in maintaining the overall function and homeostasis of an organism. The answer emphasizes the relationship between organs and organ systems, highlighting how different components come together to form complex biological structures that perform vital functions.