Characteristics of Life Characteristic of Life Description What structure is the basic unit of life? Made of one or more cells (pg 6) What is the smallest level of organization? Displays organization (pg 8) growth: Grows and develops (pg 9) development: Why do organisms reproduce? Reproduces (pg 9) stimulus: Response to stimuli (pg 9) response: Why do organisms need energy? Requires energy (pg 10) How do organisms get energy? autotrophic: heterotrophic: homeostasis: Maintains homeostasis (pg 10) adaptation: Adaptions evolve over time (pg 10) Why do species need to adapt? Examples