B. Nothing Lives Without Energy 1. Energy, the capacity to do work, is transferred throughout the universe. Metabolism refers to the cell's capacity to extract and convert energy from its surroundings and use energy to maintain itself, grow, and reproduce. Organisms can sense changes in the environment and make controlled responses to them. Special cells receive stimuli and make appropriate responses.
Homeostasis is the maintenance of a tolerable internal environment.
Energy and Life's Organization A. Levels of Biological Organization 1. B. Interdependencies Among Organisms 1. Energy flows from the sun. All organisms are part of webs that depend on one another for energy and raw materials. All organisms are made of the same materials and function according to the same laws of energy.