To check for accuracy, compare your answers with information given in the chapter or glossary. A cell is the basic living unit. Distinguish between single-celled organisms and multicelled organisms. Arrange in order, from smallest to largest, the levels of organization that occur in nature. Define each as you list it.
Metabolism means energy transfers within the cell.
Contrast the general functions of the processes known as photosynthesis and aerobic respiration. Organisms use a molecule known as ATP to transfer chemical energy from one molecule to another. Fully describe the role of receptors in the life of organisms. Homeostasis is defined as a state in which the conditions of an organism's internal environment are maintained within tolerable limits. Reproduction is the means by which each new organism arises.