Biology The Dynamics of Life

Biology “The Study of Life”

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.)

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.

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

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.

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

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

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

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

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)

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

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.

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.

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

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

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

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

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

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

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

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