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UNIT 1 The Nature of Science UNIT OBJECTIVES What Constitutes A Living Thing Branches of Biology Scientific Method Review Units and Measurement Review Unit Conversions Review UNIT VOCABULARY WHAT IS BIOLOGY Bio = Life Ology = Study Biology = The Study of Life WHAT DOES IT MEAN TO BE ALIVE? 9 characteristics determine whether or not something is alive. 1. Movement 2. Respiration 3. Sensitivity to Stimuli 4. Growth 5. Reproduction 6. Excretion 7. Nutrition 8. Cells 9. Evolution MRS. GRENCE ACRONYM Use the MRS. GRENCE Acronym to help you remember the nine characteristics of life. M 1. Movement Living Things Move. MR 2. Respiration Living Things Breath. MRS. Sensitivity to Stimuli Living Things Respond to Their Environment. MRS. G Growth Living things Grow MRS. GRE Reproduction Living Things Give Birth to New Life. MRS. GRE Excretion Living Things Create and Get Rid Of Waste. MRS. GREN Nutrition Living Things Need to Find Nutrients For Energy. MRS. GRENC Cells Living Things are Made of Cells MRS. GRENCE Evolution Living Things Evolve HOMEWORK Study these characteristics at home and be prepared for a quiz next class period. HOW DO YOU KNOW IF SOMETHING IS ALIVE? Movement Respiration Sensitivity to stimuli Growth Reproduction Excretion Nutrition Cells and Evolution MRS. GRENCE M HOW DO YOU KNOW IF SOMETHING IS ALIVE? R S G R E N C E MRS. GRENCE BRANCHES OF BIOLOGY Synthetic Biology Research Doctor Proteomics Geneticist Surgeon Biotechnologist Cardiologist Professor Paramedic Zoo Curator Surgeon Nurse Medicine Biology Sports Medicine Veterinarian Physical Therapist Forest Ranger Anesthesiologist Biological Quality Assurance Education High School Teacher Field Assistant Conservation Environmentalist MAJOR BRANCHES OF BIOLOGY Botany – The Study of Plants Zoology – The Study of Animals (many subcategories) Cytology – The Study of Cells Ecology – The Study of Relationships and Energy Transfer Among Living Things Veterinary Science – The Study of Medicine for Animals Anatomy – The Study of the Structure of Animals and Their Parts MAJOR BRANCHES OF BIOLOGY Evolutionary biology – The Study of Evolution Paleontology – The Study of Extinct Organisms Genetics – The Study of Genes Agriculture – The Study of Farming Medicine – The Application of Science to the Human Body for Better Health Epidemiology – The Study of How Disease Spreads WHAT INTERESTS YOU ABOUT BIOLOGY? If you absolutely had to become a Biologist, what branch would you most be interested in studying. Explain your choice to me in a writing prompt. Writing prompt: 8 lines SCIENTIFIC METHOD REVIEW (a) Observation/Statement of problem (b) Research (c) State Hypothesis (d) Experimental Setup – dependent, independent and control variables (e.1) Observation and collection of data (e.2) Organization of Data (e.g. – tables and graphs) (f) Analysis of Data (g) Conclusion OBSERVATION/INFERENCE Observation: The act of describing the world around us with our senses OBSERVATION/INFERENCE Inference: A logical interpretation based on our observations and previous knowledge. OBSERVATION OR INFERENCE ACTIVITY TYPES OF OBSERVATIONS Qualitative Observation: Describes the quality (characteristic) of what you see. Exp: The lady bug is red. Quantitative Observation: Describes the quantity(number) of what you see. Exp: The lady bug has 7 spots. HYPOTHESIS Hypothesis: A measureable prediction based on observation and research. Must be testable EXPERIMENTAL SET UP Independent Variable: The variable that is deliberately changed by the experimenter Dependent Variable: The variable that the experimenter measures. Controlled Variables: Variables that the experimenter makes sure stays the same. EXPERIMENTAL SET UP Control Group: The control group is exposed to the same conditions as the experimental group, except for one variable. Experimental Group: The experimental group is exposed to the independent variable EXPERIMENTAL SET UP PRACTICE 1. A study was created to test the effects of jazz on people’s sleep patterns. The hypothesis of the experiment was that if people listened to jazz music as they fall asleep, they will sleep for longer periods of time. For the experiment, 2 groups of people were created. One group was placed in a quiet room where they went to sleep and they were timed on how long they slept. The other group was placed in a room where jazz music played softly as they began to sleep and played throughout the night. As each group awoke, their sleep times were monitored. Independent Variable: Dependent Variable: EXPERIMENTAL SET UP PRACTICE 2. A study was created to test the effects of fear in children. The hypothesis of the experimenters was that if babies were exposed to fuzzy bunnies and at the same time a loud cymbal was struck close behind them, then that child would be afraid of all fuzzy things. Another group of children would be exposed to bunnies without any loud noises. The study was carried out as planned and as a result, hundreds of young children developed fear of all cute furry bunny rabbits. Dependent Variable: ______________________ Control Group: __________________________ Independent Variable: ____________________ Experimental Group: _____________________ EXPERIMENTAL SET UP QUIZ Suzie Q wants to know the effect of different colors of light on the growth of plants. She believes that plants can survive best in white light. She buys 5 ferns of the same species, which are all approximately the same age and height. She places one in white light, one in blue light, one in green light, one in red light and one in the closet. All of the ferns are planted in Miracle-Grow and given 20 mL of water once a day for 2 weeks. After the two weeks, Suzie observes the plants and makes measurements. Hypothesis: If plant growth is affected by color of light, then white light will produce the most plant growth. 1. Independent Variable: 3. Control Group: 2. Dependent Variable: 4.Experimental Group: 5.What could be the controlled variables? 6. What types of measurements can Suzie make on the plants to determine how they did in different types of light? AN APPLE A DAY… An apple a day keeps the doctor away! Is it true? Get into groups and design an experiment that would prove whether or not an Apple a day really does keep the doctor away. Make sure you have a: Control Group Experimental Group Independent/Manipulated Variable Dependent/responding Variable AHHH!!!!! RAWR!!!! PEER REVIEW Present your experiment to your peers. But be skeptical. Could their experiment really prove that an apple a day keeps the doctor away? OBSERVATION AND COLLECTION OF DATA Careful observation and measurement of your dependent variable. ORGANIZATION OF DATA Organizing Data allows us to look for trends and helps us get a better understanding of what happened. ANALYSIS OF DATA What does your data say? CONCLUSION What was learned. Did you prove or disprove your hypothesis? Ways to improve the experiment. ONE OF THESE THINGS IS NOT LIKE THE OTHER… This guide will explain briefly the concept of units, and the use of a simple technique with a fancy name—"dimensional analysis”. WHATEVER YOU MEASURE, YOU HAVE TO USE UNITS • A measurement is a way to describe the world using numbers. We use measurements to answer questions like, how much? How long? How far? • Suppose the label on a ball of string indicates that the length of the string is 150. • Is the length 150 feet, 150 m, or 150 cm? • For a measurement to make sense, it must include a number and a unit. UNITS AND STANDARDS Number 150 feet Unit *Rule: No naked numbers. They must have units • Now suppose you and a friend want to make some measurements to find out whether a desk will fit through a doorway. • You have no ruler, so you decide to use your hands as measuring tools. UNITS AND STANDARDS • Even though you both used hands to measure, you didn’t check to see whether your hands were the same width as your friend’s. UNITS AND STANDARDS • In other words, you didn’t use a measurement standard, so you can’t compare the measurements. • Hands are a convenient measuring tool, but using them can lead to misunderstanding. UNITS AND STANDARDS • So in order to avoid confusion we use measurement standards. • A standard is an exact quantity that people agree to use to compare measurements. UNITS AND STANDARDS • In the United States, we commonly use units such as inches, feet, yards, miles, gallons, and pounds. This is known as the English system of measurement. • Most other nations and the scientific community use the metric system - a system of measurement based on multiples of ten. INTERNATIONAL SYSTEM OF UNITS • In 1960, an improvement was made to the metric system. This improvement is known as the International System of Units. • This system is abbreviated SI from the French Le Systeme Internationale d’Unites. INTERNATIONAL SYSTEM OF UNITS • The standard kilogram is kept in Sèvres, France. • All kilograms used throughout the world must be exactly the same as the kilogram kept in France because it is the standard. INTERNATIONAL SYSTEM OF UNITS • Each type of SI measurement has a base unit. • The meter is the base unit of length. INTERNATIONAL SYSTEM OF UNITS • Every type of quantity measured in SI has a symbol for that unit. • All other SI units are obtained from these seven units. REVIEW • When we measure something, we always specify what units we are measuring in. • All kinds of units are possible, but in science we use the SI system. MEASUREMENT Can you: (a) measure with a ruler in centimeters? (b) measure liquid volume using a graduated cylinder in milliliters? (c) mass in grams? (d) density in g/cm3? HOW TO MEASURE PRECISION Team1 Team2 Team3 Team4 Team5 Team6 Team7 2.65g 2.75g 2.80g 2.77g 2.60g 2.65g 2.68g 1. Find the average 1. Add up all the results and divide by the number of teams 1. 2.65+2.75+2.80+2.77+2.6+2.65+2.68/7 1. 2.72g 2. Find the margin of error. 1. Subtract the mean from your highest measurement and lowest measurement 1. 2.80 -2.72 = 0.08 2. 2.72 – 2.60 = 0.12 3. Add your margin of errors together: 1. 0.08 + 0.12 = 0.20 4. Margin of error is 0.20g HOW TO MEASURE ACCURACY: PERCENT ERROR Actual Value Measured Value 5.55 6 Actual Value - Measured Value %Error = Actual Value X 100 MEASUREMENT LAB Students will measure certain objects and collect accurate data. MEASUREMENT LAB DATA SHEET Copy this table onto a piece of paper. You will be turning this paper in, so make it neat and easy to read. Go around the classroom and get the measurements of the items in the list. Record your measurement in the measurement column. When you are done type your measurements into the Excel Spreadsheet on Ms. Roderick’s computer. Object Length of the Classroom (m) Width of the classroom (m) Height of the classroom (m) Cup 1 (mL) Cup 2 (mL) Paper clamp (g) White Out (g) Dice (g/cm3) Your Measurement Actual Measurement Accuracy Precision ACCURACY AND PRECISION Precision: Precision is how close the measured values are to each other. ACCURACY AND PRECISION Accuracy: Accuracy is how close a measured value is to the actual (true) value. ACCURACY AND PRECISION Good Measurements are both accurate and precise. ACCURACY AND PRECISION VIDEO MEASUREMENT LAB DATA SHEET Copy this table onto a piece of paper. You will be turning this paper in, so make it neat and easy to read. Go around the classroom and get the measurements of the items in the list. Record your measurement in the measurement column. When you are done type your measurements into the Excel Spreadsheet on Ms. Roderick’s computer. Object Your Measurement Actual Measurement Length of the Classroom (m) 1580.6 cm Width of the classroom (m) 642.6 cm Height of the classroom (m) 253.5 Cup 1 (mL) 91 ml Cup 2 (mL) 27 ml Paper clamp (g) 6.1g White Out (g) 33.7g Dice (g/cm3) 5 g/cm3 Accuracy Precision MEASUREMENT LAB 1. Record the actual measurements and calculate your accuracy. Write in your percent error under the accuracy column. 2. Using the measurements from your classmates record the precision of your measurements. Write your margin of error in the precision column. SOMETIMES YOU HAVE TO CONVERT BETWEEN DIFFERENT UNITS • How many seconds are in a day? • How many inches are in a centimeter? • If you are going 50 miles per hour, how many meters per second are you traveling? • To answer these questions you need to change (convert) from one unit to another. HOW DO YOU CHANGE UNITS? • Whenever you have to convert a physical measurement from one dimensional unit to another, dimensional analysis is the method used. (It is also known as the unit-factor method or the factor-label method) • So what is dimensional analysis? The converting from one unit system to another. If this is all that it is, why make such a fuss about it? Very simple. Wrong units lead to wrong answers. Scientists have thus evolved an entire system of unit conversion. DIMENSIONAL ANALYSIS • How does dimensional analysis work? • It will involve some easy math (Multiplication & Division) • In order to perform any conversion, you need a conversion factor. • Conversion factors are made from any two terms that describe the same or equivalent “amounts” of what we are interested in. For example, we know that: 1 inch = 2.54 centimeters 1 dozen = 12 CONVERSION FACTORS • So, conversion factors are nothing more than equalities or ratios that equal to each other. In “math-talk” they are equal to one. • In mathematics, the expression to the left of the equal sign is equal to the expression to the right. They are equal expressions. • For Example 12 inches = 1 foot Written as an “equality” or “ratio” it looks like =1 or =1 CONVERSION FACTORS or Hey! These look like fractions! • Conversion Factors look a lot like fractions, but they are not! • The critical thing to note is that the units behave like numbers do when you multiply fractions. That is, the inches (or foot) on top and the inches (or foot) on the bottom can cancel out. Just like in algebra, Yippee!! EXAMPLE PROBLEM #1 • How many feet are in 60 inches? Solve using dimensional analysis. • All dimensional analysis problems are set up the same way. They follow this same pattern: What units you have x What units you want What units you have The number & units you start with The conversion factor (The equality that looks like a fraction) = What units you want The units you want to end with EXAMPLE PROBLEM #1 (CONT) • You need a conversion factor. Something that will change inches into feet. • Remember 12 inches = 1 foot Written as an “equality” or “ratio” it looks like 60 inches x = 5 feet (Mathematically all you do is: 60 x 1 12 = 5) What units you have x What units you want What units you have = What units you want EXAMPLE PROBLEM #1 (CONT) • The previous problem can also be written to look like this: • 60 inches 1 foot = 5 feet 12 inches • This format is more visually integrated, more bridge like, and is more appropriate for working with factors. In this format, the horizontal bar means “divide,” and the vertical bars mean “multiply”. DIMENSIONAL ANALYSIS • The hardest part about dimensional analysis is knowing which conversion factors to use. • Some are obvious, like 12 inches = 1 foot, while others are not. Like how many feet are in a mile. EXAMPLE PROBLEM #2 • You need to put gas in the car. Let's assume that gasoline costs $3.35 per gallon and you've got a twenty dollar bill. How many gallons of gas can you get with that twenty? Try it! • $ 20.00 1 gallon = 5.97 gallons $ 3.35 (Mathematically all you do is: 20 x 1 3.35 = 5.97) EXAMPLE PROBLEM #3 • What if you had wanted to know not how many gallons you could get, but how many miles you could drive assuming your car gets 24 miles a gallon? Let's try building from the previous problem. You know you have 5.97 gallons in the tank. Try it! • 5.97 gallons 24 miles = 143.28 miles 1 gallon (Mathematically all you do is: 5.97 x 24 1 = 143.28) EXAMPLE PROBLEM #3 • There's another way to do the previous two problems. Instead of chopping it up into separate pieces, build it as one problem. Not all problems lend themselves to working them this way but many of them do. It's a nice, elegant way to minimize the number of calculations you have to do. Let's reintroduce the problem. EXAMPLE PROBLEM #3 (CONT) • You have a twenty dollar bill and you need to get gas for your car. If gas is $3.35 a gallon and your car gets 24 miles per gallon, how many miles will you be able to drive your car on twenty dollars? Try it! • $ 20.00 1 gallon 24 miles $ 3.35 1 gallon = 143.28 miles (Mathematically all you do is: 20 x 1 3.35 x 24 1 = 143.28 ) EXAMPLE PROBLEM #4 • Try this expanded version of the previous problem. • You have a twenty dollar bill and you need to get gas for your car. Gas currently costs $3.35 a gallon and your car averages 24 miles a gallon. If you drive, on average, 7.1 miles a day, how many weeks will you be able to drive on a twenty dollar fill-up? EXAMPLE PROBLEM #4 (CONT) • $ 20.00 1 gallon 24 miles 1 day $ 3.35 1 week 1 gallon 7.1 miles 7 days = 2.88 weeks (Mathematically : 20 x 1 3.35 x 24 1 x 1 7.1 x 1 7 = 2.88 ) DIMENSIONAL ANALYSIS • So you can have a simple 1 step problem or a more complex multiple step problem. Either way, the set-up of the problem never changes. • You can even do problems where you don’t even understand what the units are or what they mean. Try the next problem. EXAMPLE PROBLEM #5 • If Peter Piper picked 83 pecks of pickled peppers, how many barrels is this? • Peter Piper picked a peck of pickled peppers... Or so the rhyme goes. (What in the world is a peck?) • You need help for this one. As long as you have information (conversion factors) you can solve this ridiculous problem. EXAMPLE PROBLEM #5 (CONT) • Use this info: A peck is 8 dry quarts: a bushel is 4 pecks or 32 dry quarts; a barrel is 105 dry quarts. • WHAT?! Rewrite them as conversion factors if the info is not given to you that way. 8 dry quarts 1 peck or 1 peck . 8 dry quarts 32 dry quarts 1 bushel 105 dry quarts 1 barrel 4 pecks 1 bushel or or or 1 bushel . 32 dry quarts 1 barrel . 105 dry quarts 1 bushel 4 pecks EXAMPLE PROBLEM #5 • Pick the conversion factors that will help get to the answer. 83 pecks 1 barrel. Hint: Look for units that will cancel each other. • 83 pecks 8 dry quarts 1 peck 1 barrel 105 dry quarts = 6.3 barrels (Mathematically : 83 x 8 1 x 1 105 = 6.3 ) REVIEW • Dimensional Analysis (DA) is a method used to convert from one unit system to another. In other words a math problem. • Dimensional Analysis uses Conversion factors . Two terms that describe the same or equivalent “amounts” of what we are interested in. • All DA problems are set the same way. Which makes it nice because you can do problems where you don’t even understand what the units are or what they mean. TEST REVIEW The Unit 01- The Nature of Science test will include the following information: Characteristics of Life Be able to list the 9 characteristics of life and explain what they mean. (MRS. GRENCE) Scientific Method Make sure you know the steps of the scientific method. Experimental Set up Be able to determine the independent, dependent and controlled variables and control and experimental groups of an experiment. Observation and Inference Be able to make observations and inferences and determine the difference between each. Measurement Know what units are used for specific measurements Accuracy and Precision Know the difference between accuracy and precision Be able to calculate percent error. Dimensional Analysis Be able to convert units using dimensional analysis. Branches of Biology Be able to write about a branch of biology that was interesting to you.