Biology The Dynamics of Life Biology The Study

Biology The Dynamics of Life

Biology “The Study of Life”

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

Observations o 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. 1. Qualitative observations DESCRIBE = descriptions such as color, odor, sound, and texture (using the senses). 2. Quantitative observations MEASURE = using an instrument of measurement to measure the amount or number.

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

The Scientific Method OVERVIEW 1. Identify a PROBLEM to solve. 2. Make a HYPOTHESIS. 3. TEST the hypothesis and COLLECT DATA. (a controlled experiment) 4. PUBLISH the results. 5. Draw a CONCLUSION and [perhaps] develop a THEORY.

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

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

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

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

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

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

The Scientific Method REVIEW 1. Identify a PROBLEM to solve. 2. Make a HYPOTHESIS. 3. TEST the hypothesis and COLLECT DATA. (a controlled experiment) 4. PUBLISH the results. 5. Draw a CONCLUSION and [perhaps] develop a THEORY.

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

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

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

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

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

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

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

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

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