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Slide 1 Biology Study of life Slide 2 Chapter 1 Biology ..\..\Integrated\PowerPoints HOlt\Ch01\60001.swf Slide 3 Biologist Study Study Diversity of Life (ex. Jane Goodall studies “ How chimpanzees behave in wild”) Research Disease – What causes disease? – How does body fight disease? – Develop vaccines – New medicines Develop technologies – “bionic” hand – Store and transport blood plasma for transfusions-saved countless soldiers life WWII. Improve Agriculture Preserve the environment Slide 4 Characteristics Of Living Things LIVING THINGS….. made of cells based on genetic code reproduce grow and develop adjust to their surroundings--respond adapt and evolve obtain and use energy maintain stable internal environment Slide 5 Living Things Are Organized Composed of one or more cells that are based genetic code. Organization: an arrangement of parts (cells) for the performance of the functions necessary to life Slide 6 Organisms Number of Cells Multicellular – Organisms made of many cells (ex. monkey and trees) Unicellular – One cells organisms ( ex. Amoeba) Slide 7 Types of Cells Prokaryotes – an organism, characterized by the absence of a nuclear membrane and by DNA that is not organized into chromosomes. (ex. bacteria) Eukaryotes – an organism composed of one or more cells containing visibly evident nuclei and organelles (ex. plants and animals) Slide 8 Living Things Make More Living Things Reproduction: Production of an offspring by an organism. Species: Organisms that can interbreed and produce fertile offspring in nature. (Reproduction is not essential for an individual organism, but for continuation of a species) Slide 9 Types of Reproduction •Sexual – Requires two parents and offspring are not identical •Asexual – Requires one parent and offspring identical Slide 10 Living Things Change During Their Lives single cell grows and takes on the characteristics of its species. Growth: Increase in the amount of material and formation of new structures in an organism. Development: All of the changes that take place during the life of an organism. Slide 11 Living Things Adjust to Their Surroundings Environment: Living and nonliving surroundings to which an organism must constantly adjust (air, water, weather, temperature, other organisms, other factors) Stimulus: Any condition in the environment that requires an organism to adjust Response: A reaction to stimulus Slide 12 Homeostasis Organism’s regulation of its internal environment to maintain conditions suitable for survival. Slide 13 Homeostasis Slide 14 Obtain and use materials and energy •Used to grow, develop and reproduce •Metabolism-chemical reactions through which an organism builds up or breaks down materials. Slide 15 Living Things Adapt and Evolve Adaptation: Evolution of a structure, behavior, or internal process that enables an organism to respond to stimuli and better survive in an environment. Evolution: Gradual accumulation of adaptations over time. Slide 16 Do Now: Suppose you want to test phone cover/skins to decide which is best for protecting your cell phone. What materials would you need? What procedure would you follow? How would you determine which cover best protected your phone? Slide 17 A common misperception of science is that science defines "truth." Science does not define truth; rather, it defines a way of thought. It is a process in which experiments are used to answer questions. This process is called the scientific method. Slide 18 The Advantages of Method Clarifies our thoughts Uses human potential Ends aimless wandering Aids in transfer of learning Guides us to new Trains for change and knowledge innovation Helps ideas gather shape Is a repeatable procedure Organizes our thoughts Encourages thinking The Opposite of Method is Chance Wasted time Quick fixes Wrong analysis Wasted energy Haphazard guesses Wandering aimlessly No Solutions Mistakes and errors Confusion Misdirection Slide 19 Chapter 1 Scientific Method Slide 20 Scientific Method: Series of organized steps/procedures that scientist use to solve problems and answer questions. (A process for investigating nature) Observing and Stating the Problem Collecting Data/Gathering Information Form a Hypothesis Perform an Experiment Analyze Data Draw Conclusions based on your hypothesis and experiment. Report Results Slide 21 Observing /Observations Sees, hears, or in some way notice something no one has noticed before. If the facts don't fit the theory, change the facts. -- Albert Einstein Slide 22 State the Problem A scientist can’t begin to solve a problem until it is clearly stated. For instance, when going to the doctor you tell the doctor what is wrong. (e.g. you have a sore throat) In lab the Problem is always stated in the form of a question. Slide 23 Gather Information After defining your problem you need to gather information For instance, a doctor would ask how long you have had a sore throat, take your temperature, and examine your throat. Slide 24 Hypothesis Greek: hypo-”under”, thesis-”placing” A tentative explanation for a question or problem that can be formally tested. For instance, based on experience, the doctor theorizes that you have strep throat which can be tested in a laboratory. ..\..\Integrated\PowerPointsHOlt\Ch01\80003. swf Slide 25 Perform an experiment A procedure/series of steps that test a hypothesis under controlled conditions. Slide 26 Chapter 1 Controlled Experiment and Variable ..\..\Integrated\PowerPoints HOlt\Ch01\80004.swf Slide 27 Experiment Considerations Using Tools-Beakers, test tubes, hot plates, petri dishes, thermometers, dissecting instruments, balances, rulers, microscopes, centrifuges, radiation detectors, etc. Maintaining Safety •Minimize hazards •Know your safety symbols •Your responsibility to protect yourself as well as your classmates. Slide 28 Experimental Considerations Data Information obtained from experiment Quantitative: Numerical form (distance, height) Qualitative: Verbal Form (descriptions, behaviors) Sometimes referred to as experimental results. Slide 29 Experiment Factors Control group- group in which all conditions are kept the same (Standard used to compare with the outcome of a test) Experimental group-Test Group; receives the variable Slide 30 Controlled Experiments: Only one conditions changes Variable-The factor being tested in an experiment Independent Variable-Condition in an experiment that is changed. The only variable that affects the outcome of the experiment. (temperature, nutrients, light, soil) Dependent Variable-A condition that results from change. Depends on changes from independent variable. (height, color, etc) Slide 31 Independent Dependent Presence of bacteria Growth rate Soil nutrients Plant height Vitamins Cholesterol Levels Play Wii Fit 30 m/d Weight petri dish with growth Growth on dish medium Slide 32 Analyze Data Data collected from the experiment is analyzed. For your sore throat, a lab technician identifies the growth and records data in your chart. Slide 33 Draw Conclusion Data is used to draw conclusions. A conclusion is a logical answer to a question based on data and observations of the test material. Slide 34 Does your data support or reject your original hypothesis? If the data shows that your sore throat was caused by another kind of bacterium, you don’t have strep throat and the original hypothesis is rejected. The doctor must now revise the hypothesis to include a different cause of sore throat. If the hypothesis was supported a scientist will sometimes perform additional experiments and gather more data to strengthen their conclusion. If the experiment supports the hypothesis that you have strep throat, and the doctor feels the data is sufficient to be statistically valid they may skip further experimentation and proceed to reporting results. Slide 35 Reporting Results The last step in solving a problem scientifically is to do something with the results. This includes sharing data and suggesting remedies. Your doctor may prescribe an antibiotic to kill the bacteria. Slide 36 Chapter 1 Conducting experiments • No experiment is a failure • The results of every experiment can be used to revise the hypothesis or plan tests of a different variable. Slide 37 Scientific Theory Hypothesis successfully passes many test over a long period of time and proves useful in knitting together a large body of scientific work, it takes on the status of Theory. Theory- A tested explanation of a broad segment of basic natural phenomena. e.g. Atomic Theory Be Valid: explain observations be repeatable be predictable Slide 38 Scientific Law A concise statement in words or a mathematical equation, about a fundamental relationship or regularity of nature. e.g. During a chemical reaction, no detectable gain or loss of mass occurs. Does not explain behavior of nature, it just states the generalized experimental finding. Slide 39 Slide 40 Chapter 1 Comparing Theories and Laws ..\..\Integrated\PowerPointsHOlt \Ch01\80007.swf 80007.sw f 80007.sw f 80007.sw f 80007.sw f 80007.sw f Slide 41 Activity Create a chart that: Defines scientific law, theory and hypothesis Provide qualities/characteristics that distinguish each of them (how do I know it’s a law, theory or hypothesis) Examples of each Slide 42 Reasearch Slide 43 Research Quantitative—Controlled experiments that results in counts or measurements. – Numerical data – Graphs and tables Slide 44 Descriptive research Observational data; Written descriptions of what scientist observes. Slide 45 Science and Society Slide 46 Ethics Moral principles and values held by humans -social, ethical moral concerns when planning an investigation. Slide 47 Technology Application of scientific research Making improvements in human life and world around us Increase production of food Reduced manual labor Reduction of waste and environmental pollution. Slide 48 Metric System A decimal system of weights and measurements based on meter and kilogram. Slide 49 SI Units Slide 50 Brief Chronological History of the Metric System 1670—Gabriel Moulton, a French mathematician, proposes a measurement system based on a physical quantity of nature and not on human anatomy. 1790—The French Academy of Science recommends the adoption of a system with a unit of length equal to one ten-millionth of the distance on a meridian between Earth’s North Pole and equator. 1870—A French conference is set up to work out standards for a unified metric system. History continued… Slide 51 1875—The treaty of the Meter is signed by 17 nations, including the United States. This establishes a permanent body with the authority to set standards. 1893—The United States officially adopts the metric system standards as bases for weights and measures (but continues to use British units). 1975—The Metric Conversion Act is enacted by Congress. It states, “The policy of the United States shall be to coordinate and plan the increasing use of the metric system in the United States and to establish a voluntary conversion to metric system. (No mandatory requirements are made. History information from: Introduction to Physical Science: Shipman, Wilson, Todd, 2000 Slide 52 SI Units Consistency. Scientists use the International System of Units (SI) to make sharing data and results easier. Slide 53 SI (Le Système Internationale d’Unités) Slide 54 SI prefixes for large measurements Slide 55 SI Units for small measurements Slide 56 Conversions A roll of copper wire contains 15 m of wire. What is the length of the wire in centimeters? 1. List the given and unknown values. Given: length in meters, l = 15 m Unknown: length in centimeters = ? cm Slide 57 2. Determine the relationship between units. Looking at the table of prefixes used for small measurements, you can find that: 1 cm = 0.01 m. Also means that 1 m = 100 cm. You will multiply because you are converting from a larger unit (meters) to a smaller unit (centimeters) 3. Write the equation for the conversion. length in cm = m 100 cm 1m Slide 58 4. Insert the known values into the equation, and solve. length in cm = 15 m 100 cm 1m length in cm = 1500 cm Slide 59 METRIC SYSTEM LENGTH Number of Unit Abbreviation Approximate U.S. Equivalent Meters kilometer km 1,000 0.62 mile hectometer hm 100 328.08 feet dekameter dam 10 32.81 feet meter m 1 39.37 inches decimeter dm 0.1 3.94 inches centimeter cm 0.01 0.39 inch millimeter mm 0.001 0.039 inch micrometer µm 0.000001 0.000039 inch Slide 60 Divide by 10 or move one decimal place for each box to the left Prefix kilo hecto Deka Meter deci centi milli Abbreviation k h Dk m d c m Example kilometer hectometer dekameter meter decimeter centimeter millimeter Multiplier 1,000 100 10 1 0.1 0.01 0.001 Multiply by 10 or move one decimal place for each box to the right Slide 61 Slide 62 Organizing Chapter 1 Data Interpret line graphs, bar graphs, and pie charts. Use scientific notation and significant figures in problem solving. Identify the significant figures in calculations. Understand the difference between precision and accuracy. Slide 63 Chapter 1 Bellringer Imagine your teacher asked you to study how providing different amounts of fertilizer affected the heights of plants. You perform a study and collect the data shown in the table below. Use this data to answer the items that follow. Slide 64 Bellringer, continued 1. Which amount of fertilizer produced the tallest plants? 2. Which amount of fertilizer produced the smallest plants? 3. Plot the data on a grid like the one below. 4. Describe the overall trend as more fertilizer is added to the plants. Slide 65 Chapter 1 Presenting Scientific Data Line graphs are best for continuous change. • Line graphs are usually made with the x-axis showing the independent variable and the y-axis showing the dependent variable. • The values of the dependent variable depend on what happens in the experiment. • The values of the independent variable are set before the experiment takes place. Slide 66 Chapter 1 Line Graph Slide 67 Chapter 1 Presenting Scientific Data, continued Bar graphs compare items. • A bar graph is useful for comparing similar data for several individual items or events. • A bar graph can make clearer how large or small the differences in individual values are. Slide 68 Chapter 1 Bar Graph Slide 69 Presenting Scientific Data, continued Pie charts show parts of a whole. • A pie chart is ideal for displaying data that are parts of a whole. • Data in a pie chart is presented as a percent. Slide 70 Graphing Activity Slide 71 Significant Figures and Scientific Notations Slide 72 Using Significant Figures Precision and accuracy Precision the exactness of a measurement Accuracy a description of how close a measurement is to the true value of the quantity measured Significant figure a prescribed decimal place that determines the amount of rounding off to be done based on the precision of the measurement Slide 73 Significant Figures The significant figures (also called significant digits) of a number are those digits that carry meaning contributing to its accuracy. Slide 74 Rules for identifying significant digits 1.All non-zero digits are considered significant. Example: 123.45 has five significant figures: 1, 2, 3, 4 and 5. Slide 75 Zeros appearing anywhere between two non-zero digits are significant. Example: 101.12 has five significant figures: 1, 0, 1, 1 and 2. Slide 76 Leading (space holding) zeros are not significant For example, 0.00012 has two significant figures: 1 and 2. Slide 77 Trailing zeros in a whole number are NOT significant. For example 200 1 25000 2 10,100 3 Slide 78 When decimal point are present at end of whole number, trailing zeros ARE significant 200. > 3 25,000. > 5 10100. > 5 Slide 79 Trailing zeros in a number containing a decimal point are significant. 0.0500 > 3 0.03040 > 4 0.0230 > 3 Slide 80 Addition and Subtraction: least number of digits to right of decimal place Example: 24.46 2 digits + 4.123 3 digits 30.583 Rounds to: 30.58 Slide 81 Multiplication and Division: Quantity which has the smaller number of significant figures Example: 2.61 x 1.2 = 3.13 Rounds off to: 3.1 12.34 x 1.23 = 15.1782 Rounds off to: 15.2 Slide 82 Rounding Start with the leftmost non-zero digit (e.g. the '1' in 1 200, or the '2' in 0.0256). Keep n digits. Replace the rest with zeros. Round up by one if appropriate. For example, if rounding 0.039 to 1 significant figure, the result would be 0.04. Slide 83 Examples Rounding to 2 significant figures: 12 300 becomes 12 000 13 stays as 13 0.00123 becomes 0.0012 0.1 becomes 0.10 (the trailing zero indicates that we are rounding to 2 significant figures). 0.02084 becomes 0.021 0.0125 becomes 0.012 in unbiased rounding, while it is 0.013 in biased. 19 800 becomes 20 000 Slide 84 Scientific Notation (standard form or exponential notation) Way of writing numbers that accommodates values too large or small to be conveniently written in standard decimal notation. Slide 85 Ordinary decimal Scientific notation notation 0 1 1 × 10 1 30 3 × 10 9 5 720 000 000 5.72 × 10 −9 −0.000 000 006 1 −6.1 × 10 Slide 86 Using scientific notation,300,000,000 m/sec can also be written as 3 x 100,000,000 or in the shorter form, 3 x 108, where 8, the exponent, is the number of zeros. Slide 87 Positive exponents/Large Numbers Written in scientific notation by moving the decimal point to the left. e.g. Avogadro's number is approximately 602,200,000,000,000,000,000,000 Scientific notation : 6.022 x 1023 1. The decimal point is moved left to just after the first number 2. First number must be at least 1, but less than 10 3. In the example above, the decimal point has been moved back by 23 places. That number is now the positive exponent of the base 10. Slide 88 Negative exponents/Small Numbers Numbers less than 1 can be expressed in scientific notation by moving the decimal point to the right. e.g. 0.0006022 Standard Notation: 6.022 x 10-4 1. First number must be a least 1, but less than 10. 2. For our e.g., decimal point needs to move forward by 4 digits to the first non-zero number 3. For every place we move the decimal to the right we decrease the power of ten by one. Slide 89 Rule for Multiplication – 1. Multiply the coefficients 2. Add the exponents. 3. The base will remain 10. Rule for Division – 1. Divide the coefficients 2. Subtract the exponents. 3. The base will remain 10. Slide 90 RULE #1: Standard Scientific Notation is a number from 1 to 9 followed by a decimal and the remaining significant figures and an exponent of 10 to hold place value. Example: 5.43 x 102 = 5.43 x 100 = 543 8.65 x 10 – 3 = 8.65 x .001 = 0.00865 ****54.3 x 101 is not Standard Scientific Notation!!! Slide 91 RULE #2: When the decimal is moved to the Left the exponent gets Larger, but the value of the number stays the same. Each place the decimal moves Changes the exponent by one (1). If you move the decimal to the Right it makes the exponent smaller by one (1) for each place it is moved. Example: 6000. x 100 = 600.0 x 101 = 60.00 x 102 = 6.000 x 103 = 6000 (Note: 100 = 1) All the previous numbers are equal, but only 6.000 x 103 is in proper Scientific Notation. Slide 92 RULE #3: To add/subtract in scientific notation, the exponents must first be the same. Example: (3.0 x 102) + (6.4 x 103); since 6.4 x 103 is equal to 64. x 102. Now add. (3.0 x 102) + (64. x 102) 67.0 x 102 = Not in scientific notation 6.70 x 103 = 6.7 x 10 3 67.0 x 102 is mathematically correct/standard scientific notation can only have one number to the left of the decimal Slide 93 RULE #4: To multiply, find the product of the numbers, then add the exponents. Example: (2.4 x 102) (5.5 x 10 –4) = [2.4 x 5.5 = 13.2] and [2 + -4 = -2] = 13.2 x 10 –2 Correct scientific notation: 1.3 x 10 – 1 Slide 94 RULE #5: To divide, find the quotient of the number and subtract the exponents. Example: (3.3 x 10 – 6) / (9.1 x 10 – 8) = ? [3.3 / 9.1 = .36] and [-6 – (-8) = 2] (3.3 x 10 – 6) / (9.1 x 10 – 8) = .36 x 102 3.6 x 10 1 Slide 95 Scientific Notation ..\..\Integrated\PowerPoints HOlt\Ch01\80402.swf 80402.sw f 80402.sw f Slide 96 Chapter 1 Writing Numbers in Scientific Notation Using scientific notation • When you use scientific notation in calculations, you follow the math rules for powers of 10. • When you multiply two values in scientific notation, you add the powers of 10. When you divide, you subtract the powers of 10. Slide 97 Chapter 1 Math Skills Writing Scientific Notation The adult human heart pumps about 18 000 L of blood each day. Write this value in scientific notation. 1. List the given and unknown values. Given: volume, V = 18 000 L Unknown: volume, V = ? x 10? L Slide 98 Chapter 1 Math Skills 2. Write the form for scientific notation. V = ? x 10? L 3. Insert the known values into the form, and solve. First find the largest power of 10 that will divide into the known value and leave one digit before the decimal point. You get 1.8 if you divide 10 000 into 18 000 L. So, 18 000 L can be written as (1.8 x 10 000) L Slide 99 Chapter 1 Math Skills Then write 10 000 as a power of 10. Because 10 000 = 104, you can write 18 000 L as 1.8 x 104 L. V = 1.8 x 104 L Slide 100 Chapter 1 Math Skills Using Scientific Notation Your state plans to buy a rectangular tract of land measuring 5.36 x 103 m by 1.38 x 104 m to establish a nature preserve. What is the area of this tract in square meters? 1. List the given and unknown values. Given: length, l = 1.38 x 104 m width, w = 5.36 x 103 m Unknown: area, A = ? m2 Slide 101 Math Skills, continued 2. Write the equation for area. A=lw 3. Insert the known values into the equation, and solve. A = (1.38 104 m) (5.36 103 m) Regroup the values and units as follows. A = (1.38 5.36) (104 103) (m m) When multiplying, add the powers of 10. A = (1.38 5.35) (104+3) (m m) A = 7.3968 107 m2 A = 7.40 107 m2 Slide 102 Precision and accuracy Precision the exactness of a measurement Accuracy a description of how close a measurement is to the true value of the quantity measured Slide 103 Chapter 1 Section 3 Organizing Data Accuracy and Precision, part 1 Slide 104 Chapter 1 Section 3 Organizing Data Accuracy and Precision, part 2 Slide 105 Chapter 1 Section 3 Organizing Data Accuracy and Precision Slide 106 Chapter 1 Using Significant Figures When you use measurements in calculations, the answer is only as precise as the least precise measurement used in the calculation. The measurement with the fewest significant figures determines the number of significant figures that can be used in the answer. Slide 107 Chapter 1 Math Skills Significant Figures Calculate the volume of a room that is 3.125 m high, 4.25 m wide, and 5.75 m long. Write the answer with the correct number of significant figures. 1. List the given and unknown values. Given: length, l = 5.75 m width, w = 4.25 m height, h = 3.125 m Unknown: Volume, V = ? m3 Slide 108 Chapter 1 Math Skills, continued 2. Write the equation for volume. V=lwh 3. Insert the known values into the equation, and solve. V = 5.75 m 4.25 m 3.125 m V = 76.367 1875 m3 The answer should have three significant figures, because the value with the smallest number of significant figures has three significant figures. V = 76.4 m3 Slide 109 Understanding Concepts 1. During a storm, rainwater depth is measured every 15 minutes. Which of these terms describes the depth of the water? A. controlled variable B. dependent variable C. independent variable D. significant variable Slide 110 Chapter 1 Understanding Concepts 2. Why were scientists unable to form a theory that diseases are caused by bacteria before the late fifteenth century? F. No on tried to understand the cause of disease until then. G. Earlier scientists were not intelligent enough to understand the existence of bacteria. H. The existence of microbes could not be discovered until the technology to make high-quality lenses had been developed. I. Doctors believed they understood the disease process, so they would not accept new ideas about the causes. Slide 111 Understanding Concepts 3. What is a scientific theory? A. A theory is a guess as to what will happen. B. A theory is a summary of a scientific fact based on observations. C. A theory is an explanation of how a process works based on observations. D. A theory describes a process in nature that can be repeated by testing. Slide 112 Interpreting Graphics 4. What is the volume of the gas 40 seconds into the experiment? F. 15 mL G. 24 mL H. 27 mL I. 50 mL