八下第五单元英语重点单词

八下第五单元英语重点单词

1.Biology

Biologyisthestudyoflivingorganisms,includingtheirstructure,function,growth,evolution,anddistribution.Forexample,"Iaminterestedinbiologybecauseitallowsustounderstandhowlivingthingsfunction."

2.Microorganism

Microorganismsaresmalllivingorganismsthatcanonlybeseenunderamicroscope.Examplesincludebacteria,viruses,andfungi."Microorganismsplayanimportantroleinecosystemsasdecomposersandintheproductionofcertainfoodsandmedicines."

3.Pathogen

Apathogenisamicroorganismthatcausesdisease.Forinstance,"Pathogenssuchasbacteriaandvirusescancauseillnesseslikethecommoncold,flu,andpneumonia."

4.Immune

Beingimmunemeanshavingtheabilitytoresistorrecoverfromaninfectionorillness."Vaccineshelpusdevelopimmunityagainstvariousdiseases."

5.Antibiotic

Anantibioticisatypeofmedicationthatkillsorslowsdownthegrowthofbacteria."Doctorsoftenprescribeantibioticstotreatbacterialinfectionssuchasstrepthroatorurinarytractinfections."

6.Vaccination

Vaccinationistheadministrationofaweakenedorkilledmicroorganismtostimulatetheimmunesystemagainstaspecificdisease."Childhoodvaccinationsprotectagainstpreventablediseasessuchasmeasles,mumps,andrubella."

7.Organism

Anorganismisanyindividualformoflife,suchasananimal,plant,orbacterium."Allorganismsrequireenergy,reproduce,andrespondtotheirenvironmentinordertosurvive."

8.Photosynthesis

Photosynthesisistheprocessbywhichgreenplantsusesunlight,carbondioxide,andwatertoproduceglucoseandoxygen."Duringphotosynthesis,plantsconvertsunlightenergyintochemicalenergytofueltheirgrowth."

9.Respiration

Respirationistheprocessbywhichlivingorganismsexchangegases,inhalingoxygenandexhalingcarbondioxide."Humanrespirationoccursinthelungs,whereoxygenistakeninandcarbondioxideisexpelled."

10.Decomposer

Adecomposerisanorganismthatbreaksdowndeadorganicmatter,recyclingnutrientsbackintotheecosystem."Examplesofdecomposersincludebacteria,fungi,andcertaintypesofworms."

11.Ecosystem

Anecosystemisacommunityoflivingorganismsinteractingwithoneanotherandtheirphysicalenvironment."TheAmazonRainforestisanincrediblydiverseandcomplexecosystem."

12.Extinction

ExtinctionreferstothecompletedisappearanceofaspeciesfromtheEarth."Manyspecieshavegoneextinctduetohumanactivitiessuchasdeforestationandpollution."

13.FossilAfossilisthepreservedremainsortracesofanorganismthatlivedinthepast."Paleontologistsstudyfossilstolearnaboutancientlifeformsandhowtheylived."14.GenomeAgenomeisthecompletesetofgeneticmaterialofanorganism."TheHumanGenomeProjectmappedallthegenesinthehumangenome,providingvaluableinformationaboutgeneticdiseasesandinheritedtraits."15.HabitatAhabitatisthenaturalenvironmentinwhichanorganismlives."Manyanimalsarelosingtheirhabitatsduetourbanizationandhabitatdestruction."16.InsectAninsectisasmall,wingedcreaturewiththreepairsoflegs,representingthelargestgroupofanimalsonEarth."Beesareimportantinsectsthatpollinateflowersandhelpintheproductionoffruitsandvegetables."17.MammalAmammalisawarm-bloodedvertebrateanimalthatnourishesitsyoungwithmilkfromitsmother."WhalesarethelargestmammalsonEarth,buttheybreatheairinsteadofwater."18.NutritionNutritionistheprocessbywhichlivingorganismsobtainandusenutrientsfromfood."Abalanceddietisessentialforgoodnutritionandoverallhealth."19.OxygenOxygenisacolorless,odorlessgasthatisessentialforrespirationandcombustion."Plantsreleaseoxygenduringphotosynthesis,whichisnecessaryforthesurvivalofmanyorganisms."20.ParasiteAparasiteisanorganismthatlivesinoronanotherorganism,knownasthehost,anddependsonitfornourishment."Tapewormsareparasitesthatcanliveintheintestinesofhumansandanimals."21.PlantAplantisalivingorganismthattypicallygrowsinsoil,hasleaves,stems,androots,andusesphotosynthesistoproducefood."Grassisatypeofplantthatcoversmanylawnsandfields."22.ProteinAproteinisacomplexmoleculemadeupofaminoacids,whichareessentialforthestructureandfunctionofcells."Meat,fish,andbeansaregoodsourcesofprotein."23.ReproductionReproductionistheprocessbywhichlivingorganismsproducenewindividualsofthesamespecies."Birdsreproducebylayingeggs,whicheventuallyhatchintochicks."24.SkeletonAskeletonistheinternalframeworkofbonesthatsupportsthebodyofavertebrateanimal."Thehumanskeletonconsistsof206bonesandprovidessupport,protection,andmovement."25.TemperatureTemperatureisameasureofthehotnessorcoldnessofanobjectorenvironment."Thehumanbodymaintainsarelativelyconstantinternaltemperaturetoensureproperfunctioningofcellsandorgans."26.VirusAvirusisatinyinfectiousagentthatcanonlyreplicateinsidethecellsofalivingorganism."Thefluviruscausesrespiratoryillnessandcanbeverycontagious."27.WildfireAwildfireisanuncontrolledfirethatspreadsacrossgrasslands,forests,orotherareas."Wildfirescanhaveadevastatingimpactonecosystems,destroyingplants,animals,andtheirh