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Do Now… How is a scientific investigation done?. Methods of Science Objectives: - Differentiate among control, independent variable, and dependent variable - Identify the scientific methods a biologist uses for research -Describe the difference between Theory and a Law. Ms. Scerra.
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Methods of ScienceObjectives:- Differentiate among control, independent variable, and dependent variable- Identify the scientific methods a biologist uses for research-Describe the difference between Theory and a Law Ms. Scerra
The Scientific Method • Biologists work in different places in order to answer a question they may have. • Biologist all use similar methods to gather information and to answer questions, the Scientific Method • Even though scientists do not use scientific methods in the same way each time they conduct an experiment, they observe and infer throughout the entire process.
Quick Review • Observation – direct way of gathering information in an orderly way. • Inference – the process of combining what you know with what you have learned to draw a logical conclusion.
Form a Hypothesis • After observing, reviewing prior information and questioning, a biologist is able to format a hypothesis. • A Hypothesis is a testable explanation of a situation. • A Hypothesis that is supported through experiments and data is then accepted in the scientific community.
Serendipity • The occurrence of accidental or unexpected but fortunate results. For example: • The discovery of Penicillin. • A petri dish was left out overnight and the next morning the scientist discovered a green fuzzy substance growing on it. Later they discovered it properties that it destroyed bacteria cells.
Think-Pair-Share • Can you think of an event that was serendipitous? • Has serendipity occurred in your life? • Can you think of something that came about or was discovered through serendipity?
Experimental Design • With that hypothesis, an experiment is created. • Experiment – investigation of a phenomenon in a controlled setting to test a hypothesis. • Each Experiment has: • Control Group – a group used for comparison. • Experimental Group – the group exposed to the factor being tested. • Independent Variable – the tested factor and may affect the outcome of the experiment. • Dependent Variable – results from or depends on changes to the independent variable. • Constant – a factor that remains fixed during an experiment.
Collect and Gather Data • Data- information gained from observations. • Quantitative Data- measurements of time, temperature, length, or other factors. • Qualitative Data- descriptions of what our senses detect.
Displaying Data-Organize your data into a chart-Make a graph out of the chart
Analyze Your Data to Form a Conclusion • What can we conclude from this graph?
Report Your Conclusions • After experimenting you must come to some type of conclusion either disproving or proving your hypothesis! • Conclusions are published so others can review the results and discuss the merit of the experiment.
Do Now! • What is the SI unit system of measurement? • Why is it used? • What unit would I use to describe length? Mass? Volume?
Objectives • Explain the nature of science • Compare and contrast the English and metric systems • Practice conversions between metric units.
Nature of Science • *Uses Scientific Theory… • Theory • Explanation of natural phenomenon supported by many observations and experiments over time • Explains how or why something happens. • Ex: The Big Bang Theory (not the show!), Cell Theory • Law • A statement about an event that occurs in nature • Doesn’t give us the “how” or “why” explanation • Usually expressed as a mathematical equation • Ex: The Law of Gravity, Boyle’s Law, etc.
Expands Scientific Knowledge • Science is under constant reevaluation of what is known. • Ex. Classification, Food Pyramid • Can lead to new knowledge • Reevaluation cycle continues!
Challenges Accepted Theories • Scientists debate each other’s ideas • Science accommodates new information as it is discovered
Questions Results • Scientist can find data that is not consistent with current scientific understanding • These inconsistencies often lead to further investigations
Test Claims • Conclusions are reached after • Controlled experiments • Unbiased investigations • Large amounts of data
Undergoes Peer Review • Experiments are reviewed by scientist’s peers. (Peer review ) • Evaluated by other scientists who are in the same field or who are conducting similar research.
Measurements Used in Science • Different methods used for measuring • International System of Units (SI)- what scientists all over the world use • Measured in groups of 10
Length - SI • SI uses the meter • Measures how long something is • Tools: Ruler, meter stick
Volume • SI uses m3 • Most often we use liter • Measures how much space Something takes up
Mass and Weight • Mass = how much matter something has • SI units are kilogram (kg) • Weight = force of gravity on an object
Time and Temperature • Time: period between two events • SI unit is seconds (s) • Temperature: how much heat contained in an object (how hot or cold something is) • SI unit is Kelvin (K) • Scientists often use Celsius (C)
Conversions • 4 kiloliters= ___________ hectoliters • 36.87 millimeters= ________ decameters • 0.098 meters = ___________ micrometers • 56.7 decimeters= _________ decameters