What Science Is and Is Not ► Science ► Organized way of using evidence to learn about the natural world
What Science Is and Is Not Cont’d ► Goal of Science: ► Investigate and understand the natural world ► Explain events ► Use explanations to make predictions that could be beneficial
Thinking Like A Scientist ► Step 1 ► Observation: ► Process of gathering info. about events or processes in a careful, orderly way
Thinking Like A Scientist Cont’d ► Step 2 ► Gathering info. from observations (data) ► 2 Types of Data ► 1. Quantitative: expressed as numbers ► 2. Qualitative: descriptive and involve characteristics that can’t easily be measured
Thinking Like A Scientist Cont’d ► Step 3 ► Make inferences based on data ► Inference ► Logical interpretation based on prior knowledge or experience
Thinking Like A Scientist Cont’d ► Step 4 ► Explain and interpret your evidence which leads to a… ► Hypothesis ► Proposed scientific explanation for a set of observations that can be tested
Hypothesis ► Must be proposed in a way that can be tested ► Tested by performing controlled experiments or by gathering new data
Explaining and Interpreting Evidence ► Do not copy ► Researchers often work in teams to analyze, review, and critique each other’s data and hypotheses. ► A review process helps ensure conclusions are valid. ► To be valid, a conclusion must be based on logical interpretation of reliable data.
What does science involve? 1. Asking questions 2. Observing 3. Making inferences 4. Testing hypotheses
Science as a Way of Knowing ► Scientific knowledge is always changing ► Good scientists are skeptics
Science and Human Values ► Decisions in science depend on: ► Society ► Economy ► Laws ► Moral principles ► We decide what and how things get done when we vote
The Scientific Method Section 1-2 ► How do scientists test hypotheses? ► Controlled Experiments ► Must change only 1 variable at a time ► Why??????????
Designing an Experiment ► Steps: 1. Ask a question 2. Form a hypothesis 3. Set up a controlled experiment 4. Record/Analyze results 5. Draw conclusion
Designing an Experiment Cont’d ► Step 1: Asking a question ► Ex.) ► How do organisms come into being?
Designing an Experiment Cont’d ► Step 2: Forming a hypothesis ► Ex.) Spontaneous Generation ► Life could come from nonliving matter ► People thought maggots came from meat ► 1668, Redi proposed a different hypothesis ► Maggots came from eggs that flies laid on meat
Designing an Experiment Cont’d ► Step 3: Setting up a controlled experiment ► Manipulated Variable ► Deliberately changed ► Responding Variable ► Variable that is observed and that changes in response to the manipulation
Copyright Pearson Prentice Hall Designing an Experiment Redi’s Experiment Controlled Variables: jars, type of meat, location, temperature, time Covered jars Uncovered jars
Copyright Pearson Prentice Hall Designing an Experiment Redi’s Experiment Manipulated Variable: Gauze covering that keeps flies away from meat Responding Variable: whether maggots appear Maggots appear. Several days pass. No maggots appear.
Designing an Experiment Cont’d ► Step 4: Recording and analyze results ► Use written records of observations/data ► Use drawings when needed ► Use computers to analyze data ► Store data online for others to view
Designing an Experiment Cont’d ► Step 5: Draw a conclusion ► Use data to evaluate hypothesis and draw a conclusion ► Ex.) Redi’s results supported his hypothesis
Designing an Experiment Cont’d ► Finally Step 6: ► Investigations must be repeated ► Why???? ► To make sure results are correct
Repeating Investigations ► Needham ► Challenged Redi’s results ► Said that spontaneous generation could occur when conditions were right
Copyright Pearson Prentice Hall Repeating Investigations Spallanzani's Test of Redi's Findings Spallanzani's Test of Redi's Findings Gravy is boiled.
Copyright Pearson Prentice Hall Repeating Investigations Spallanzani's Test of Redi's Findings Spallanzani's Test of Redi's Findings Flask is open. Flask is sealed.
Copyright Pearson Prentice Hall Repeating Investigations Spallanzani's Test of Redi's Findings Spallanzani's Test of Redi's Findings This backed up Redi’s findings Gravy is teeming with microorganisms. Gravy is free of microorganisms.
Repeating Investigations ► Louis Pasteur ► Disproved the hypothesis of spontaneous generation for sure ► Showed all living things come from other living things
Copyright Pearson Prentice Hall Repeating Investigations Pasteur’s Experiment Broth is boiled Broth is free of microorganisms for a year. Curved neck is removed. Broth is teeming with microorganisms.
Impact of Pasteur’s Work ► Saved the French wine industry b/c it gave them a way to preserve wine to keep it from souring ► Saved silk industry b/c it was becoming endangered by a silkworm disease ► Began to uncover the nature of infectious diseases, showing they came from organisms
Question ???? ► How does a scientific theory develop?
How A Theory Develops ► Evidence builds over time ► Hypothesis that is supported by it becomes so well supported ► It must then be considered a theory ► Theory ► Well-tested explanation that unifies a broad range of observations ► These can be changed; they are not concrete
What is Biology ► Bio/logy- ► Science that employs the scientific method to study living things
Characteristics of Life Fig. 1-15 p.16-17 ► Made of cells ► Reproduce ► Based on a universal genetic code ► Grow and develop ► Obtain and use materials and energy ► Respond to environment ► Maintain a stable enviro. ► Change over time as a group
Big Ideas ► What do you think this means? ► All biological sciences are tied together they overlap each other p.18-19 ► Go over pg. 18-20 with class
Branches of Biology ► Zoology ► Botany ► Paleontology
Levels of Organization ► Biosphere ► Ecosystem ► Community ► Population ► Organism ► Groups of cells ► Cells ► Molecules
Tools and Procedures ► What units are used to measure things? ► Metric System ► How do scientists analyze data? ► Use graphs
Tools and Procedures Cont’d ► Lab Techniques ► Cell Cultures- ► Group of cells grown in a nutrient solution from a single original cell ► Cell Fractionation- ► Solution is put into a centrifuge and spun to separate materials out by densities
Microscopes ► 2 Types ► 1. Light- produce images by focusing light rays ► 2. Electron- produce images by focusing beams of electrons
History of Microscope ► Use notes from West Greene here