1. Chapter 1 – Biology: The Study of Life
Section 1.2 – The Methods of Biology p

2. Answer this question…
Why do earthworms crawl to the surface after it rains?

3. Observing + Hypothesizing
Curiosity is often what motivates biologists to try to answer simple questions about everyday observations
The knowledge obtained when scientists answer one question often generates other questions or proves useful in solving other problems

4. Scientific Methods
Common steps that scientists use to gather information and answer questions
No “fixed” set of steps to follow
Usually begin with an observation
Something seen that peaks a scientist/person’s curiosity
You want to know “why”

5. Hypothesis
An explanation for a question or a problem that can be tested
Formed once the observations are made to explain the observations
Many hypotheses can be formed in any investigation

6. Experimenting
An experiment is generally an investigation to test a hypothesis by collecting information under controlled conditions

7. Parts of an Experiment Control Group Experimental Group
Part of experiment that is standard
Used for comparison
Experimental Group
The “test” group
Receives an experimental treatment

8. Experimental Conditions
Independent variable
The one factor that was changed in the two groups
For example, adding fertilizer to plants
Dependent variable
An observed or measured second condition as a result of the independent variable
For example, the plant’s growth rate

9. Tools used in Experiments
Beakers
Test tubes
Petri dishes
Microscopes
Spectrophotometers

10. Lab Safety
Importance?
To minimize hazards
Safety symbols

11. Data gathering Data Information obtained from investigations
Two types:
Numbers
Words

12. Data analysis Purpose? So the scientist can come up with a conclusion
Was the hypothesis supported by the data
Was it not supported?
Are more data needed?

13. Reporting + Verifying data
By reporting data, scientists can examine one another’s work
Published in scientific journals
Scientists can then verify the results by repeating an experiment
If the results are the same, the hypothesis can then be accepted by the scientific community

14. Theory
An explanation of a natural phenomenon that is supported by large body of scientific evidence obtained from many different investigations and observations
Examples:
The Cell Theory
The Theory of Evolution by Natural Selection
Theory of Relativity
Big Bang Theory
Atomic Theory

15. Laws/Principles Facts of nature that are generally known to be true
Examples:
Law of Gravity