2. III. Importance of Biology All organisms are interdependent, and humans are organisms. In order to understand life on earth and the future of humans and other organisms, biologists study interactions between living things and their (our) environment.

3. IV. Scientific process—a series of problem solving steps; stages and examples. A.Observations 1. Description—collecting, noting or perceiving objects or events using the senses 2. Example—decline in # of frogs and salamanders; change in pH of lakes

4. B. Asking question 1. Brainstorm ideas about cause and effect; research 2. Ex.—Is acid precipitation getting into ponds?

5. C. Forming hypothesis and making predictions 1. hypothesis—statement that can be tested by additional observations and experiment 2. prediction—expected outcome if hypothesis is correct

6. 3. Ideally, together consist of “If…, then…” statement a. Ex.—If salamander eggs are placed in solutions of increasing acidity (hyp.) then fewer eggs will hatch. (pred.)

7. D.Controlled experiment 1. control group—group that receives NO experimental treatment 2. Independent variable a. Desc.—ONE factor that changes b. Ex.—solns. of increasing acidity 3.Dependent variable a. Desc.—variable that is measured— data (preferably numeric) b. Ex.--# of salamanders hatched from eggs

8. E. Drawing conclusions—deciding whether data do/do not support the hypothesis *(absolute proof never possible b/c new data in future may alter conclusion)

9. F. Publishing results (peer review)— reasons for 1. ensures that proper experimental procedures used 2. checks that data justify conclusion 3. provide new info for other scientists 4. allows other scientists to confirm validity of experiments

10. G. Establishing a theory 1. Theory—set of related hypotheses that have been tested and confirmed many times by many scientists; a generally accepted scientific principle 2. absolute certainty—never possible, BUT some theories are VERY strongly supported 3. ex.—cell theory, evolutionary theory/natural selection