1. Lesson Overview Lesson Overview Studying Life 1.3 Studying Life

2. Lesson Overview Lesson Overview Studying Life THINK ABOUT IT Think about important news stories you’ve heard. Bird flu spreads around the world, killing birds and threatening a human epidemic. Users of certain illegal drugs experience permanent damage to their brains and nervous systems. Reports surface about efforts to clone human cells. These and many other stories involve biology—the science that employs scientific methodology to study living things. The Greek word bios means “life,” and -logy means “study of.”

3. Lesson Overview Lesson Overview Studying Life Characteristics of Living Things What characteristics do all living things share?

4. Lesson Overview Lesson Overview Studying Life Characteristics of Living Things What characteristics do all living things share? Made of Cells Able to Reproduce Based on a Genetic Code Grow & Develop Need Material & Energy Respond to the Environment Maintain Internal Balance Evolve

5. Lesson Overview Lesson Overview Studying Life Made of Cells Living things are made up of one or more cells—the smallest units considered fully alive. Despite their small size, cells are complex and highly organized. Unicellular Organisms: made of 1 cell Multicellular Organisms: made of several cells

6. Lesson Overview Lesson Overview Studying Life Able to Reproduce Living things reproduce, which means that they produce new similar organisms. Asexual Reproduction: one parent divides in two; results in offspring that are identical to the parent Sexual Reproduction: involves two parents; results in offspring that are genetically different than the parents

7. Lesson Overview Lesson Overview Studying Life Based on a Genetic Code All organisms store the complex information they need to live, grow, and reproduce in DNA. That information is copied and passed from parent to offspring and is almost identical in every organism on Earth.

8. Lesson Overview Lesson Overview Studying Life Grow & Develop All living things grow at some point. Some, like bacteria, just grow in size. Multicellular organisms go through stages of development

9. Lesson Overview Lesson Overview Studying Life Need Material & Energy Living things obtain and use material and energy to grow, develop, and reproduce. The combination of chemical reactions through which an organism builds up or breaks down materials is called metabolism. Energy can be obtained through photosynthesis or by consuming energy stored by photosynthesis.

10. Lesson Overview Lesson Overview Studying Life Respond to the Environment Organisms detect & respond to stimuli A stimulus is a signal to which an organism responds. External Stimuli light temperature Internal Stimuli blood sugar level infection

11. Lesson Overview Lesson Overview Studying Life Maintain Internal Balance Organisms maintain a relatively stable internal environment (internal temperature and water), even when external conditions change dramatically. Homeostasis: maintaining internal balance

12. Lesson Overview Lesson Overview Studying Life Evolve Over generations, groups of organisms evolve, or change over time.

13. Lesson Overview Lesson Overview Studying Life Interdependence in Nature All forms of life on Earth are connected into a biosphere, or “living planet.” Within the biosphere, organisms are linked to one another and to the land, water, and air around them. Relationships between organisms and their environments depend on the cycling of matter and the flow of energy.

14. Lesson Overview Lesson Overview Studying Life Organization of Life Biosphere Ecosystem Community Population Organism Groups of Cells Cells Molecules

15. Lesson Overview Lesson Overview Studying Life Biosphere

16. Lesson Overview Lesson Overview Studying Life Ecosystem

17. Lesson Overview Lesson Overview Studying Life Community

18. Lesson Overview Lesson Overview Studying Life Population

19. Lesson Overview Lesson Overview Studying Life Organism

20. Lesson Overview Lesson Overview Studying Life Groups of Cells

21. Lesson Overview Lesson Overview Studying Life Cells

22. Lesson Overview Lesson Overview Studying Life Molecules