1. Biology
The Dynamics of Life

2. Biology
“The Study of Life”

3. Characteristics of “LIFE”
Organization
Reproduction
Growth & Development
Respond to its environment
Stimulus
Response
(Homeostasis – The ability to control its internal environment. Adjustment of water & minerals in an organism to achieve balance.)

4. Observations
A scientist uses his senses of sight, touch, hearing, and smell to examine an object in detail. He may use instruments to extend these senses.
Qualitative observations DESCRIBE = descriptions such as color, odor, sound, and texture (using the senses).
Quantitative observations MEASURE = using an instrument of measurement to measure the amount or number.

5. Observations Accident #1 Accident #2 Accident #3
A scientist improves his skills of observation and his communication skills by practice.
Observe the following and describe as much as you can.
Accident #1
Accident #2
Accident #3

6. The Scientific Method OVERVIEW
Identify a PROBLEM to solve.
Make a HYPOTHESIS.
TEST the hypothesis and COLLECT DATA. (a controlled experiment)
PUBLISH the results.
Draw a CONCLUSION and [perhaps] develop a THEORY.

7. 1. OBSERVATION leads to identifying a problem to solve.
“Observing the world around you is the foundation of scientific investigation.”

8. 2. Making a HYPOTHESIS.
an EXPLANATION for a question or problem that can be formally TESTED.
Not a RANDOM GUESS.

9. 3. Collecting DATA. (numbers)
Test the hypothesis in a controlled EXPERIMENT can be used to obtain data to test a HYPOTHESIS.

10. 4. PUBLISH results
allows other scientists to repeat the experiment and VERIFY the results.

11. 4. Forming a THEORY. (not an unproven idea or hunch)
A THEORY is a hypothesis that is supported by a LARGE body of scientific evidence.
(not an unproven idea or hunch)

12. Also
6. Developing new HYPOTHESES.
7. Revising the THEORY.

13. The Scientific Method REVIEW
Identify a PROBLEM to solve.
Make a HYPOTHESIS.
TEST the hypothesis and COLLECT DATA. (a controlled experiment)
PUBLISH the results.
Draw a CONCLUSION and [perhaps] develop a THEORY.

14. Parts of a Controlled Experiment
Control – the STANDARD against which the results of the experiment are COMPARED.
INDEPENDENT Variable (I.V.) – the condition that is tested because it affects the outcome of the experiment.
DEPENDENT Variable (D.V.) – the condition in an experiment that results from the changes made to the independent variable.
CONSTANTS – the conditions that remain the same in all of the experimental groups.

15. Francesco Redi’s Experiment
Observed – Maggots appeared on meat a few days after flies were present

16. Francesco Redi’s Experiment
Prediction – Flies produced maggots and keeping flies away from meat would prevent the appearance of maggots.

17. Francesco Redi’s Experiment
Hypothesis - IF the gauze covering keeps flies away from the meat, THEN no maggots will appear.

18. Francesco Redi’s Experiment
Independent variable - gauze covering that keeps flies away from meat.

19. Francesco Redi’s Experiment
Dependent variable - whether maggots appear on the meat.

20. Francesco Redi’s Experiment
Controlled variables - Jars, type of meat, location, temperature, time.

21. Francesco Redi’s Experiment
Data - showed that maggots appeared on the meat without gauze – but not on covered jars.

22. Francesco Redi’s Experiment
Conclusion - Maggots formed only when flies came into contact with the meat. Not spontaneous generation.