# Chapter 1 and 2

Chapter 1 and 2

Chapter 1 and 2Scientific Method, MeasurementandThe Characteristics of Living Things

Science What is it? What does it mean? The goal of Science is to understand theworld around us. Uses the scientific method.2

StepsScientific MethodState a problem• Usually from observationResearch the problem• Why look any further if the problem has alreadybeen solvedForm a hypothesis• Best guess as to a possible solutionDesign an experiment to test the hypothesis• Must be able to be replicated3

StepsRecording and analyzing the dataForming a conclusion• Either the hypothesis wasTrue - move on to another problemorFalse – develop a new hypothesisIf hypothesis was true: Publish the data4

Theories and Laws A Theory is established whenA hypothesis has been tested often enoughthat it is unlikely that it will be disproven byfuture tests. A Law is a principle that is universallyaccepted.Example• Newton’s Laws of MotionRevised after Einstein5

Scientific Measurement Two systemsEnglish• Royalty decided what a measurement wasExample: yard = length of King’s arm, cubit = length of forearmUses fractionsMetric [System International]• After French Revolution, system for the common manBased on 10; uses decimals6

English System Length – inches, feet, yards, milesFathom, Chain Mass – ounces, pounds, tonsDifference between mass and weight Volume – pints, quarts, gallons Temperature – Fahrenheit degrees7

Length – meterMetric [SI]System International Mass – gram Volume – liter Temperature – Celsius degrees8

Bigger to smaller Kilo Hecto Deca Standard – meter, liter, gram Deci Centi Milli9

Temperature One easy formula5(f) = 9(c) + 160• Simply place the known temperatureand solve10

Dimensional Analysis:the “H” methodStep by step. [One Step Conversion]1. Write out the conversion: 8 miles = ___ feet2. Draw “+” or “H”3. In upper left corner write unit you arestarting with then write the same unit in thelower right corner4. In upper right corner write unit needed atend5. Choose conversion that has both units6. Place numbers next to units7. Solve11

Characteristics of Living Things What is alive?Virus?? Biotic Factors Dead vs. Non-living12

Living Things are Made up of one or more structures calledcellsTwo major types of cells• Plant• AnimalSingle cell vs. multi-cellular• Bacteria vs. Human13

Able to reproduceTwo types• SexualInvolves two types of cells• Sperm – male• Egg- femaleOccurs in plants and animals• AsexualSingle set of genesPlants and a very few animals14

Grow and developGrow – a change in size• Your first grade picture and your 9 th grade pictureDevelop – a change in form• After pubertyMale’s chests get bigger, voice changes and hair on faceFemale’s develop breasts, hips get wider and hair underarms15

Obtain and use energyProcess of putting things together is –Anabolism• Storing energy for later useProcess of releasing energy is – Catabolism• Breaking down substances into simpler onesBoth processes make up – Metabolism• Sum total of all chemical reactions with in anorganism16

Respond to their environmentPositive response• Like it!• Food, moneyNegative response• Don’t like it• Pain, something taken awayHomeostasis• Maintain the balance within the organism17

Biology at various levels Molecular Cellular Multicellular Population Global18

Tools of a Biologist MicroscopesTypes• Compound LightMicroscopeUses two or more lensUses light to see throughthe objectPower• Eyepiece x objective= _X19

Electron MicroscopeResolution of between 500,000 and 1 million XTwo types• Transmission• ScanningDrawbacks• Specimens must be placed in a vacuum20

Scanning ProbeTrace the surfaces Other toolsCentrifugeMicromanipulationCell cultures21

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