The Science of Biology

The Science of BiologyChapter 1What Is Science?Science - a study of the natural world; to understand how it works

Thinking Like a ScientistObservations using the senses to gather observations about something in the natural worldData those observations become data when in a controlled expInference a logical and rational conclusion based on prior knowledge Hypothesis a possible answer to a question at hand; usually based off prior information; must be testableScientific MethodAn Organized way to solve a problem using a series of steps

Scientific MethodQuestionHypothesis (Ifthen..)Variables manipulated and respondingMaterialsProcedureObservations/Data/GraphsConclusions/DiscussionForming a HypothesisDone after initial observationsBased off of prior knowledge; logical inferences or imaginative guessesCan a group of scientist have competing hypothesis?Do all hypotheses have to be correct?

Forming a HypothesisSpontaneous generation life arising from non-lifePrior to Louis Pasteur in 1881, it was the most common belief of how life aroseFrancesco Redis experimentRejected spontaneous generation and opted for biogenesisThought that flies laid eggs on raw meat, producing the maggots that were seen a few days later

Francesco Redis experimentControlled exp- only one variable is changes at a time and all others are Kept constant.Controlled variables: jars, type of meat, location, temp, timeManipulated variable gauze covering or not covering the jarsResponding variables: whether maggots appearNeedhams Test of Redis Findings wanted to disprove Redis expSaid that Spontaneous Generation could occur under right conditionsSealed a bottle of gravy and heated itClaimed heat killed any living thing in gravyAfter several days found it swarming with activity/lifeSpallanzanis Test of Needhams ExperimentProduced different results. Why?Needham didnt boil long enoughNeedham didnt seal the flask fast enoughNeedham also claimed that air was necessary for life even life formed from SGSo what was found in air that Spallanzani didnt know about?

Louis PasteurSolved the problems experienced with Needham and SpallanzaniDesigned a flask that had a long curved neck; opened to airMicroorganisms from air did not make their way through the neck into flaskShowed as long as broth was protected from micro., it remained free of living thingsAfter yr broke flask and micro. Quickly appearedLouis Pasteur Exp

Anton Van LeeuwenhoekPerfected first scientific microscope in 1673Simple in design, but allowed him to see microorganisms for first timeCalled them animalculesLeeuwenhoke time vs. Our timeAt time of Van L. only 2 kingdoms: animal and plantUnder our six kingdom classification system, they could belong to any of them: Eubacteria, archaebacteria, Protista, Fungi, Plantae, and AnimaliaTheoryTheory - a well supported hypothesis; the highest level of proof in the scientific world; there are no absolutes in scienceSo why do people often refer to theories in a neg. connotation; as not having enough evidence or support?Studying LifeBiology the study of life; the science that seeks to understand the living worldIs it easy to determine what is alive and not? Many living and nonliving things share same characteristicsToys, cars, clouds move whereas trees, mushrooms live in one spot

Living ThingsShare the following characteristicsMade up of cells multicellular and unicellularAble to reproduce asexual and sexualBased on a universal genetic codeGrow and developObtain and use materials and energy metabolismRespond to their environmentMaintain a stable internal environment homeostasisChange over time - evolutionCellsEverything on earth is made up of atoms; tiny balls of charged particlesBut only living things have organized those atoms to for proteins, lipids, nucleic acids, etc to make cells

Paramecium w/ cilia, flagella

Human cheek cellsReproductionHow org produce new organisms2 basic types: asexual & sexualSexual repro cells from two diff parents unite to produce first cell of new orgAsexual repro now org has a single parent; hydraGenetic codeDeoxyribonucleic Acid (DNA) what allows us to be different from other sp, from each other; allows us to think, talk, walk, breathe, have immunity against diseaseGrowth and DevelopmentEvery org grows and develops from the moment they are conceivedNewborn has already grown for 9 monthsBabies start out as balls of cells and eventually develop into babies we see in the worldAdults still grow things like muscle, hair, fat, etc

Materials and energyEvery org must eat; without food you dieOrg use a lot of energy and nutrients every day If not replenished, then org cannot function correctly and will eventually die

Response to EnvironmentWe all respond to changes; whether big or smallSmall changes include widening of pupil in low light to allow you to see betterLarge changes include evolving thicker fur to deal with dropping tempsThe bigger the change the more time it takes usuallyInternal BalanceIn mammals, internal body temp must be maintained in order to surviveIf body temp drops too much, must be reheated or die of hypothermiacold-blooded org like lizards also have an internal envi; their bodies allow for a wider temp range, but cannot survive outside of that rangeIn order to maintain internal body temp, must expend greater amount of energyEvolutionWe all grow oldOur sp is continually evolving, never stopping

Branches of BiologyParisitology study of parasites and parasitismPathology study of diseases and the causes, processes, nature, and development of diseaseNeurobiology study of nervous system, including anatomy, physiology, even pathologyMycology study of fungiBranches of biologyHistology study of cells and tissue, a microscopic branch of anatomyEvolutionary Biology study of the origin and decent of sp over timeEcology the study of the ecosystem as a complete unit, with an emphasis on how sp and groups of sp interact with other living beings and non-living elementsAnatomy study of the animal form, with an emphasis on human bodiesBranches of BiologyCryobiology study of the effects of lower than normally preferred temps on living beingsEntomology study of insectsGenetics study of genes and heredityLevels of OrganizationSome fields focus on the study of living systems at different levels of organizationMolecular biologists and cell biologists study some of smallest living systems.Population biologists and ecologists study some of largestLevels of OrganizationBiosphere part of Earth that contains all ecosystemsEcosystem community and its nonliving surroundingsCommunity populations that live together in a defined areaPopulation group of org of the same sp in the same areaOrganism individual living thingGroups of cells tissues, organs, and organ systemsCells Smallest fx unit of lifeMolecules groups of atoms; smallest unit of most chemical compoundsAspect of life influenced by Biology!!!

HomeworkRead pg 23 #1-3

Conflicts in ScienceCan occur at any level of ScienceEven among the most respected scientists in the worldSir Richard doll and Monsanto CorporationMoral and Ethical GuidelinesScientists must follow some moral and ethical guidelines when designing an exYou cant infect people with a fatal diseaseYou cant perform actions that put the participants in unnecessary harm or painNo animal crueltyIf a participant in your study wants to leave, they can do so w/o any reprecussionsMoral and Ethical Guidelines5) Participants must be fully informed prior to enrolling in a study6) Participants must fully understand what is going to happen during the study; those with diminished capacity must be represented by appropriate legal guardians7) Will the study provide useful info8) All groups of people are equally representedMoral and Ethical GuidelinesPatient rights have not always been observedUS govt and the infamous Tuskegee StudyTuskegee Study40yr studyTracked 600 African American Males in deep southStarted after Great Depression; low on fundsTrack untreated syphilis (a bacterial infection usually transmitted during sexual contact; may also be transmitted from mother to child during birthing process)Tuskegee StudyCan be cured with PenicillinDespite knowledge of cure, researchers failed to inform participants Participants never told of study, instead they were bribed into yearly medical examsIn end, several male participants died as well as infected family to diseaseDeaths were preventable, but due to science were notTreated as test subjects not humansTuskegee StudyAs a result organizations were formed to mandate and standardize the human and animal test subject rightsBelmont Report1979 Ethical Principles and Guidelines for the protection of Human subjects of Research3 fundamental ethical principles for using humans for researchRespect for persons; protecting the autonomy of all people and treating them with courtesy and respect and allowing for informed consent

Belmont Report2) beneficence: maximizing benefits for the research project while minimizing risks to the research subjects3) Justice: ensuring resonable, non-exploitative, and well considered procedures are administered fairly (the fair distribution of costs and benefitsNational Human Investigation BoardOLAW (Office of Laboratory Animal Welfare)homeworkRead 1-4Measurement SystemUse the Metric System/ International System of Units (SI)Microscopes: Light vs. ElectronCompound Light MicroscopeElectron MicroscopeProduce magnified images by focusing visible light raysMost common1000x magnificationLiving or deceased org can be viewedLight passes through two lensesStains can be used to look at diff parts of an org or cellProduce magnified images by focusing beams of electronsViews much smaller objects No Color imagesTransmission electron Microscope shine a beam of electrons through thin specimenScanning electron mic. Shine a beam of electrons back and forth across an obj = 3D imageDeceased specimens onlyCompound Light Microscope

Electron Microscope

Laboratory TechniquesUse variety of techniques to study cellsCell cultures allow a single cell to reproduce creating enough cells for study; used to study responses under controlled substances, to study interactions bt cells and to select specific cells for further studyLaboratory TechniquesCell Fractionation separates diff parts of cell based on densityCell membrane destroyed when whirled in a blenderBased on how heavy each cell component is they separated out into band in a test tubeCan easily see this with bloodIf blood sits for an extended period of time, red blood cells sink to bottom of a test tube and the clear plasma and water stay above

Lab Safety

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Test Next Class!!!