Ch. 1 Biology in the 21 st Century

1. Ch. 1 Biology in the 21st Century

2. Science is a way of thinking, questioning, and gathering evidence.

3. biosphere = everywhere life exists Earth is home to an incredible diversity of life. • The biosphere includes all living things and all the places they are found.

4. Biodiversity is the variety of life. • Biodiversity generally increases from the poles to the equator. • Biodiversity is greater in areas with consistently warm temperatures. Biodiversity is greater closer to the equator.

5. All organisms share certain characteristics. • Biology is the scientific study of all forms of life (the study of living things).

6. I. General Terms: 1. Science – a way of finding out about the physical world 2. Biology – The study of living things

7. 3. Organism – • any living thing • All are made of one or more cells. • All need energy for metabolism. (called?) • All respond to their environment. • All have DNA that they pass on to offspring.

8. II. Overview of science

9. V. Levels of Organization

10. III. The Scientific Method • A standardized means of organizing and evaluating information to reach a valid conclusion. • (easy definition- a step by step way to solve a problem)

11. Like all science, biology is a process of inquiry. • Scientists make careful and systematic observations. • Scientists record observations as data. • Scientists form a hypothesis as a possible answer to a     question. • Scientists test their hypotheses and analyze their data.

12. Stop use doc. Cam • Atom – element – compound – molecule – cell – tissue – organ – organ system – organism – population – community – ecosystem – biosphere

13. General Steps for the Scientific Method • Observe • Define a problem • Hypothesis • Experiment • Collect , Analyze and Record Data • Form a Conclusion • Scientific Theory……… • Scientific Law

14. Terms expanded: • Hypothesis – an idea that explains your observations • A valid hypothesis has three characteristics • 1. Testable • 2. Unbiased • 3. Repeatable

15. If a hypothesis satisfies these criteria it can be accepted as a Scientific Theory

16. A theory explains a wide range of observations. • Theories explain a wide range of observations and experimental results. • A theory is supported by a wide range of scientific evidence. • Theories can change based on new evidence.

17. IV. Other Characteristics of Science • 1. Objective • 2. Subjective

18. 3. Quantitative • 4. Qualitative

19. 5. Variable • 6. Independent variable • 7. Dependent variable • 8. Control

20. 5. Dependant – the variable that changes because of what happens in the experiment. Graphed on the y axis • 6. Independent – the variable that the experimenter changes – the one we are testing. Graphed on the x axis • 7. Variable – a changeable factor ex. Temperature, time, food etc. • 8. Control – a group that does not get tested. It is used as a “means” of comparison

21. V. Review of the Scientific Method • Prefixes for the metric system

22. VI. Characteristics of Living Things – see next ppt. – the next slides are just “talking” points for in class

23. Organisms must maintain homeostasis to survive in diverse environments. • Homeostasis is the maintenance of constant internal conditions.

24. Homeostasis is the maintenance of constant internal conditions. • Homeostasis is usually maintained through negative feedback. • Negative feedback systems return a condition to its normal (set) point.

25. Behaviors and adaptations can help maintain homeostasis.

26. Evolution explains the unity and diversity of life. • Evolution is the change in living things over time. • The genetic makeup of a population of a species changes. • Evolution can occur through natural selection of adaptations. • Adaptations are beneficial inherited traits that are passed to future generations.

27. Evolution accounts for both the diversity and the unity of life.