Biology: The Science of Life

1. Biology: The Science of Life The Characteristics of Life

2. What is an Organism? An organism is anything that has or once had all of the characteristics of life. • Characteristics of Life • Made of One or More Cells • Displays Organization • Grows and Develops • Reproduces • Responds to Stimuli • Requires Energy • Maintains Homeostasis • Adaptations Evolve Over Time

3. Made of One or More Cells • A Cell is the basic unit of structure and function in all living things. All cells are made up of an organization of atoms and molecules. Cells of multicellular organism cells are organized into specialized groups to work together. Displays Organization

4. Grows, Develops, & Reproduces Most organisms begin as one cell. Growth is the addition of mass to an organism. Often includes the formation of more cells. Development involves changes that occur in the organism throughout its life. Reproduction is the production of offspring. This usually occurs in organisms of the same species.

5. Responds to Stimuli Requires Energy • Stimulus • Anything that causes some sort of reaction by an organism • Can be from either the internal or external environment • Energy • Ability to do work • Cannot be created or destroyed • Organisms need energy to function-growth, body processes • Food provides this energy • Plants and some unicellular organisms use sunlight. • Other organisms consume other animals • Response • Reaction to a stimulus • Critical for survival

6. Maintains Homeostasis • Homeostasis • Regulation of an organism’s internal conditions to maintain life Adaptations Evolve Over Time • Adaptation • Any inherited characteristic that results from changes to a species over time