首页
试卷库
试题库
当前位置:
X题卡
>
所有题目
>
题目详情
已知函数f(x)=|x+a|+|x﹣2|. (1)当a=﹣4时,求不等式f(x)≥6的解集; (2)若f(x)≤|x﹣3|的解集包含[0,1],求实数a的取值范围.
查看本题答案
包含此试题的试卷
高三下学期数学《》真题及答案
点击查看
你可能感兴趣的试题
已知函数fx是定义在R.上的偶函数f0=0当x>0时fx=logx.1求函数fx的解析式2解不等式f
已知函数fx是定义在R.上的奇函数当x<0时fx=exx+1给出下列命题①当x>0时fx=e﹣xx﹣
4
3
2
1
已知函数fx=lnx﹣ax﹣1.1求函数fx的极值2当a≠0时过原点分别作曲线y=fx与y=ex的切
已知函数fx的定义域为R.对于任意的xy∈R.都有fx+y=fx+fy且当x>0时fx<0若f﹣1=
已知函数y=fx若存在x0使得fx0=x0则称x0是函数y=fx的一个不动点设二次函数fx=ax2+
已知函数fx在定义域0+∞上为增函数且满足fxy=fx+fyf3=11求f9f27的值2解不等式fx
已知函数fx=2xgx=+2.1求函数gx的值域;2求满足方程fx-gx=0的x的值.
已知函数fx=ax3+cx+da≠0是R.上的奇函数当x=1时fx取得极值﹣2.求fx的单调区间和极
已知函数fx=|2x+1|﹣|x|﹣2.1解不等式fx≥02若对任意的实数x都有fx﹣2a2≥|x|
已知函数fx的定义域是{x|x≠0}对定义域内任意x1x2都有fx1·x2=fx1+fx2且当x>1
已知函数fx=x2-2a+1x+2alnx1若a=2.求fx的极值.2若a>0.求fx的单调区间.
已知函数fx对任意xy∈R.都有fx+y=fx+fy且x>0时fx<0f1=-2.1求证fx是奇函数
已知函数fx=ax3+bx2+cx+da≠0的图象经过原点f′1=0若fx在x=﹣1取得极大值2.1
已知函数fx对任意xy∈R.都有fx+y=fx+fy且x>0时fx
已知函数fx=|x﹣1|+|x+1|﹣2.1求不等式fx≥1的解集2若关于x的不等式fx≥a2﹣a﹣
已知函数fx对任意的mn∈R.都有fm+n=fm+fn-1并且x>0时恒有fx>1.1求证fx在R.
给出下列四个命题其中正确命题的序号是①已知fx=x2+bx+c是偶函数则b=0②若函数fx的值域为[
①②⑤
①②④⑤
①②③⑤
①③④⑤
已知函数fx=ax3+cx+da≠0是R.上的奇函数当x=1时fx取得极值﹣2.1求fx的单调区间和
已知函数fx是定义在R.上的奇函数当x<0时fx=exx+1给出下列命题①当x>0时fx=﹣e﹣xx
4
3
2
1
已知函数fx=ax﹣ab∈N*f1=且f2<2.Ⅰ求ab的值Ⅱ判断并证明函数y=fx在区间﹣1+∞上
热门试题
更多
脂肪酶催化脂肪水解为甘油和脂肪酸科研人员为探究油水比例对脂肪水解度的影响[水解度=脂肪水解量/脂肪总量×100%]做了相关实验结果如图.下列叙述错误的是
在一项探究土壤细菌对植物X生长效应影响的实验中将多株生理条件相同的植物X随机均分为甲乙两组将等量的AB两种细菌分别加入到培养两组植物X的土壤中培养条件相同且适宜.统计植物X在实验的第1天和第60天的平均高度结果如图所示回答下列问题1已知细菌AB均需从植物根部获取营养进行繁殖据此分析细菌A或B在土壤中分布呈现的空间特征是.2已知细菌AB与植物X的种间关系是寄生或互利共生现需要增加1组实验丙组才能更准确地判断细菌AB与植物X的关系丙组实验的处理方式是.若结合丙组实验结果能证明AB两种细菌与植物X之间属于不同的种间关系则丙组实验结果是.
某校研究性学习小组对某农业生态系统进行了调査分析并绘出了如图所示的食物网. 请据图回答 1在这个生态系统的食物网中有条食物链. 2该食物网中青蛙占有个营养级青蛙和蜘蛛的关系属于. 3请你写出蛇获得能量最多的一条食物链此食物链中蛇为初级/次级/三级/四级消费者. 4研究小组的同学对鼠这种活动能力强活动范围大的动物进行种群密度调查通常采用法. 5该生态系统的功能主要是能量流动物质循环和.其中能量沿食物链流动的特点是.
人体注射乙肝疫苗后机体发生相关的应答反应.下列叙述错误的是
正常白眼雌果蝇和正常红眼雄果蝇杂交产生的子一代中出现一只基因型为XbXbY白眼雌果蝇甲和一只基因型为OXB红眼雄果蝇乙.下列相关叙述错误的是
Ourmindisapowerfulthingwhichcaneitherimproveorruinourmood.Manyofushaveproblemswithnegativethoughtsplayingonthechannelofourmindsbutifyou'reengaginginitconstantlyandyoubelieveititcouldbedestroyingyoursenseofself﹣esteem.1 Whatcanyoudo?Herearesomesuggestions 1.Liveinthemoment Self﹣talkissosubtlethatweoftendon'tnoticeitseffectonourmoodandbeliefsystems.Keythingstonoticeareifonlyorwhatifstatementstheformerkeepyoustuckinthepastwithregretwhilethelatterkeepyoufearfulofthefuture.2Sostayinthepresentmoment. 2.Visualizethegoodthings Ifwewanttochangethenegativetapesplayinginourheadswehavetovisualizeourselvespositively﹣thatmeansseeingyourselfnon﹣judgmentally.Howwouldthatlook? Drawapictureinyourmindandexpandonit. 3.3 Whateveryoubelieveyou'llexperiencemoreandyou'llalsofindyourselfbehavinginwaysbelievethatareinyourbeliefs.Sostartbelievingthebestaboutyourselfactasifyoubelievethatyou'reavaluableandworthyperson. 4.Developpositivethoughts 4Whatareyourstrengths?Whatareyougoodat?Keepyourthoughtsinthehere﹣and﹣now.InsteadofsayingI'mnotgoodenoughtrysayingIamcapable.IacceptmyselfthewayIam. Thinkingpoorlyaboutourselvesgetsusnowhereandisextremelyself﹣limiting.5 A.Payattentiontothecauses B.Recognizethatactionsalwaysfollowbeliefs C.Thereisnothingyoucandoaboutthepastandthefutureisn'thereyet. D.Inshortitbringsyourfocusonyourfailuresandthatgetsyounowhere. E.Negativethoughtsaccountforbadfeelingsthathookyouintobelievingthatyou'reafailure. F.Insteadofalwaysputtingyourselfdownthinkofsomethingsyouactuallylikeaboutyourself. G.Decidetodaytoturnoffthenegativeself﹣talkchannelinyourmindanddevelopyourtruepotential.
Cassielivedalonelylife.Shewouldwanderthroughtheforesteating1fallfruitswhileotherbirdsflewamongthetrees. Whycannotyoufly?theywouldask.Yourweaklittle2wingcannotevenliftyouofftheground!theywouldteaseher.You're3shametobirdstheywouldoffendher. Cassiewasfeelingincreasinglyfrustratedand4usesoshemadeuphermindtoleavetheforestforgood.Justasshewalkedfreefromtreessheheardadeepvoice5callfrombehind.Cassieturnedaround.6wasalargetreethatsignaledtohertocomebackintotheforestWeneedyoubadlyheresaidthetree.Werelyonyou7eatourfruitsandspreadourseeds.Theotherbirdsmaythinkyouareworthlessbutyouareactually8muchusefulbirdintheforest.Pleasedon'tgoyouareirreplaceable.Cassicbeamedforthefirsttimeinmanyweeksand9returntotheforest.Thefruitshadnevertastedsogood. It'seasytocompareyourskillstotheabilitiesofothersandfeelinadequate.It'seasytolistentothenegativevoicesofothersandbelievethem.Butbear10mindthatyouareessentialyouareremarkableandyouareirreplaceable!
Reutersreportedthatthescientist'seffortsgotrewardedwhenthetwinchickenswereclonedinthelabafteryearsofexperiments.Thisbreakthrough1possibleenabledpeopletobringtheiradoredpetsbacktolife.2itbotheredhimfromtimetotimethattheirhealthwasinpoorconditionbecausetheywere3abletoresistillnesses.Thisdrawback4casthimdown.Merelytwoweekslatertheclonesandtheircarrierdied5struckfrustrationintohisheart.Heretiredbeforeheattainedhisambitionandbecameamemberofanoperachorustorelievehisdepression. Shortlyafterwardsthemediapublishedaconservative6argueobjectingtocloningowingtomoralproblemsandsuggestedcommercialprofitsfromcloning7forbid. When8interviewthescientiststaredatthedecorationsontheceilingthinkingforawhileandthensaidI'mnotinfavour9anyarbitraryassumptionbut10undertakecloningdoesdifferfromthestraightforwardprocedureofmakingloafsoutofflour.Untilweaccumulateenoughexactknowledgeanypracticeisinvainandisboundtofail.
某课题组为了研究赤霉素GA3和生长素IAA对植物生长的影响切取菟丝子茎顶端2.5cm长的部分茎芽置于培养液中无菌培养.实验分为AB两组分别培养至第18天再用适宜浓度的激素处理30天测量茎芽长度结果如图甲.另一小组将洋葱根尖分生区细胞用不同浓度的生长素处理若测得经某一浓度的生长素处理前后的细胞内DNARNA蛋白质含量相对值的变化如图乙所示.下列说法正确的是
某DNA上的W基因发生突变导致合成的mRNA上一个碱基C变成A.下列叙述错误的是
新一代基因编辑CRISPR/Cas9术的实质是用特殊的引导序列sgRNA将Cas9酶﹣“基因剪刀”精准定位到所需切割的基因上然后进行编辑.科研人员设想利用新一代基因编辑技术来预防艾滋病.回答下列问题 1动物细胞中没有编码Cas9酶的基因可通过构建用法将其导入受体细胞最终表达出Cas9酶. 2CCR5蛋白是HIV病毒入侵机体细胞的主要辅助受体之一HIV通过识别膜通道蛋白CCR5侵入宿主细胞.为有效阻止HIV侵染新分化生成的T淋巴细胞科研人员将sgRNA序列导入骨髓细胞中以构建sgRNA﹣Cas9酶复合体.Cas9酶可以催化键断裂以实现对DNA序列的定向切割.设计sgRNA序列需要根据的核苷酸序列原因是. 3为检测T淋巴细胞的CCR5基因是否成功被编辑采用技术检测是否含有CCR5基因还需要对蛋白进行检测.
下列关于细胞及其产生的物质的叙述正确的是
神经元的离子通道是跨越磷脂双分子层的蛋白质对特定刺激发生反应时才瞬时开放促使特定离子顺浓度梯度运输如图所示.下列相关叙述错误的是
大肠杆菌可以直接利用葡萄糖也可以通过合成β﹣半乳糖苷酶的乳糖分解为葡萄糖和半乳糖加以利用.将大肠杆菌培养在含葡萄糖和乳糖的培养基中.测定其细胞总数及细胞内β﹣半乳糖苷酶的活性变化.据图分析下列叙述合理的是
已知某植物花色性状受三对独立遗传的等位基因控制同时存在三种显性基因时开大红花只存在两种显性基因时开红花只存在一种显性基因时开粉红花不存在显性基因时开白花.回答下列问题 1纯合大红花与白花的品种杂交获得F1F1自交F2的表现型及比例为F2中开粉红花的基因型有种红花中纯合子所占的比例为. 2从F2中选出甲乙两株粉红花植株请通过一代杂交实验判断甲乙两植株是否一含有同种显性基因.要求写出杂交方案预期结果及结论
WWP2基因在肿瘤细胞中高度表达WWP2蛋白参与肿瘤细胞的生长存活和转移等.为获得较多WWP2蛋白利用基因工程技术设计引物其中正向引物5′含有EcoRI酶切位点反向引物5′含有XhoI酶切位点.将WWP2基因与相应载体构建重组质粒导入人胚肾细胞.回答下列问题 1利用上述的引物以肺癌细胞的cDNA为模板通过扩增的编码序列获得需要的目的基因片段. 2把获得的目的基因片段和相应载体都用进行酶切分别在5′端与3′端形成避免自身环化.然后利用将目的基因片段和相应载体连接得到重组质粒. 3先将重组质粒导入经处理过的大肠杆菌细胞培养后从中分离得到较多的重组质粒. 4培养人胚肾细胞时先用使人胚肾细胞分散成单个细胞用含有的合成培养液培养并将培养瓶置于体积分数为5%的与空气混合气体的培养箱中培养. 5将重组质粒导入人胚肾细胞中48小时后提取蛋白质并检测到WWP2蛋白说明. 6致癌因子会损伤肺泡细胞中的使原癌基因和抑癌基因发生突变.研究WWP2蛋白的表达为肺癌治疗新靶点奠定了基础.
阅读下面短文根据所给情节进行续写使之构成一个完整的故事. WhenIwastenyearsoldIlivedwithmyfamilyinasmallhouseinruralSouthJersey.IoftenaccompaniedmymothertotheA&Ptobuygroceries.WithoutacarwewalkedandIwouldhelphercarrythebags. Mymotherhadtoshopeverycarefullyasshewasawaitressandhersalarybarelysustained勉强维持us.OnedaywhileshewasweighingpricesapromotionaldisplayfortheWorldBookEncyclopediacaughtmyeye.Thevolumeswerebeautifullycream﹣colored.VolumeIwasninety﹣ninecentswithaten﹣dollarpurchase. AllIcouldthinkofwhileshoppingwasthebook.Istoodattheregister收银台withmymotherholdingmybreathasthecashierranguptheitems.Itcametooverelevendollars.Mymotherproducedafivesomesinglesandahandfulofchange.AsshewascountingoutthemoneyIsomehowfoundthecouragetoaskfortheencyclopedia百科全书.Couldwegetone?Isaidshowingherthedisplay.It'sonlyninety﹣ninecents. Ididnotunderstandmymother'sincreasinganxietyshedidnothaveenoughchangeandhadtosacrificealargecanofpeastopaytheamount.NotnowPatriciashesaidsternly.Todayisnotagoodday.Ipackedthegroceriesandfollowedherhomeupset. ThenextSaturdaymymothergavemeadollarandsentmetotheA&Palone.Twoquartsofmilkandaloafofbread﹣﹣﹣that'swhatadollarin1957.IwentstraighttotheWorldBookdisplay.TherewasonlyonefirstvolumeleftwhichIplacedinmycart购物车.Ididn'tneedacartbuttookonesoIcouldreadasIwentupanddowntheaisles.AlotoftimewentbyandIknewIhadtoleavebutIcouldn'tbeartopartwiththebook.WithnodetectiveinsightIimpulsively冲动地putitinsidemyshirtandzippedupmyjacket.IwasatallskinnykidandIamcertaintheshapeofthebookwasobvious. Paragraph1MyheartbeatingrapidlyIheadedfortheregister. Paragraph2Backhome.ItoldmymotherwhatIhadpromisedthedetective.
PrepareYourselfforaBetterTOEFLScore TheTOEFListhemostwidelyusedlameassessmentexamforAmericancollegesoruniversities.ManyforeignstudentsworryabouttakingtheTOEFLbecauseitisessentialtomeettheirgoals.1Butalowtestscorewilllimittheirchoicesforfinancialaidandadmissiontotopschools.SohowtoprepareyourselfforabetterTOEFLscore? Whatwillyoufocuson? PlanwhenyouwilltaketheTOEFL.Ifpossibleregistertotakethetestevenifthedateisseveralmonthsfromnow.Thiswillgiveyouagoodreasontostudy.Takeasampletestonlineorfromatestpreparationbooktofindoutwhereyouneedtoimprovethemost.2Thiswillhelpyoutoplanyourstudiestodeveloptheskillsyouneedtogetabetterscore. 3 TheEducationalTestingServicewebsitehasafreeonlinecoursetohelpyoupreparefortheTOEFL.Therearealsosamplepreparationquestions.ApartfromansweringthosequestionstrytosurroundyourselfwithEnglish.ListentostoriesonVOA'sLearningEnglishwebsite.WatchmovieswhereEnglishisspoken.ReadEnglish﹣languagenewspaperstokeepupwithnewwordsthatrelatetocurrenteventsandtechnology. Whenwillyoustudy? 4Butifyourpracticetestscoreismorethan20pointsbelowyourgoalyoumayneedtoimproveyouroverallEnglishabilityandthatmaytakeyears.Togetagoodscoreyouneedtosetasidetimetostudysetgoalsandmeasureyourprogress. TherealgoalofthetestistomeasurehowwellastudentcancommunicateinanEnglish﹣speakingclassroom.5 A.Howwillyoustudy? B.Donotdependoninformaladviceortricks. C.Goodmarksonthetestwillopenmanydoors. D.Doyoudowellinreadingbutnotsowellinlistening? E.Exportssaythatyoushouldstudyforatleasttwomonthsbeforetakingthetest. F.ExposeyourselftoEnglishonadailybasisandimprovementissuretofollow G.ATOEFLscoremaybenecessarytogetastudentvisatoanEnglish﹣speakingcountry.
阅读下面短文根据其内容写一篇60词左右的内容概要. Paperlessofficewasfirstcoinedin1975.Fourdecadeslaterwe'restillchasingthepaperlessofficedream.Takethefinancialindustryforexample﹣itisoneoftheslowerindustriestohugdigitaltransformation.Manyfinancialinstitutionstodaystillsendouttradeconformationsbymail.Icantellyoufromfirsthandexperiencethatgoingpaperlessisbynomeansimpossible.TheCentricDigitalofficeisapaperlessworkenvironmentwherealltheofficeoperationsgodigitalwhichhasamazedourbusinesspartners. Actuallycompaniesneedtostressthebenefitsofadigitalcultureforcommunications.Goingpaperlesscansavetimeandmoney.Youcouldsaygoodbyetocostlyrepairsofficesupplyorderswastedemployeetimeandsoon.Besidesforbiddingpaperintheofficeforcesinformationtobe100%digitalwhereyoucanmakeendlessamountsofbackups备份whicheasilyincreasetransparency透明.Nottomentiontoptalentswanttoworkfordigitalcompanies. Youmightthinkthesecrettoapaperlesscompanyispurelytechnology.Wellnotreally.ThankstoproductslikeiPadssmartphonesandcloudservicestheabilitytogopaperlessishighlyaccessible.Yetevenwithallthistechnologycompaniescontinuetorelyonpaper.It'snotbecausetheydon'thaveaccesstothetechnologybutbecausethey'relackingthepoliticsorganizationalstructureandstrongdesiretochange.Inordertogopaperlesscompaniesneedtochangethewaytheythinkandoperate.Thedecisionneedstobemadeandcriedoutandeveryoneneedstoworktogethertomakeit. Yesthepaperlessofficehasbeenaverylongtimeinthemaking一butitnolongerhastobe.Withnumerousamountsofsoftwareservicesappsandtechnologyavailabletodaytheonlythingweneedtodoistomakethedecisiontogopaperlessandseeitthrough.
突触是两个神经元之间或神经元与其支配的肌肉和腺体细胞之间的连接部位可分为化学突触和电突触.回答下列问题1与体液调节相比神经调节具有写出两点等特点.2化学突触以化学物质传递信息.一些化学突触的突触后膜上存在某类氯离子通道这些氯离子通道偶联神经递质的受体若特定神经递质与这些受体结合会使突触后神经元受到抑制.产生该抑制的原理是.3电突触的突触前膜和后膜由一些通道直接连接这些由蛋白质组成的通道允许带电离子通过.在电突触中神经冲动以信号的形式传送其传送速度比在化学突触中更填快或慢.
下列关于细胞癌变的说法错误的是
Forsomepeoplewalkingorrunningoutdoorsisaeatwaytoworkout.Whatmaynotbesopleasantisseeingtrashallovertheground.Wellsomepeoplearedoingsomethingaboutit.Theyareplogging! PloggingbeganinSweden.ThenamecombinetheSwedishwordplockawhichmeanstopickupandthewordjoggingwhichmeanstorunslowly.ASwedishmannamedErikstartedthemovementin2016.OntheWorldEnvironmentDaywebsiteEriksaysthathemovedtoStockholmfromasmallcommunityinnorthernSweden.Eachdayhewouldridehisbiketowork.Concernedabouttheamountoftrashandlitterhesaweachdayonhiswaytoworkhetookmattersintohisownhands. PloggingbythattermmayhaveofficiallybeguninSweden.Butmanypeoplewhoexerciseoutdoorshavebeendoingthisforyears.TakeJeffHorowitzforexample.HeisapersonaltrainerinWashingtonD.C.Heoftenpicksuptrashwhilerunningoutside.Heevenasturneditintoagamehewilltrytopickupthetrashwithoutstopping.Ididn'tknowitwasathingreally.Thisisjustmypersonalethics道德标准whereIgoforarunandifIhappentoseeapieceofgarbagelyingaroundandit'swithinreach﹣﹣﹣itisakindofalittletestformetoseeifIcangrabitandthrowitinanearrashcanwithoutstopping.AndthatwayIthinkitgivesmealittleexerciseandalittlefocusformyrun.Andithelpscleanuptheneighborhoodheannounced. Todayloggingisanofficialactivityonethatisbecomingincreasinglypopular.Citiesaroundtheworldnowholdloggingevents.Iwouldjusthopepeoplewouldthinktwicebeforedroppingagarbageontheround.Wehavecontainers…seemsoneveryblock.Soit'seasytoputyourgarbageinthetrashcans.Ijustthinkpeopleshouldthinkaboutitalittlebitmore.Idohopeonedaytherewillnotbeaneedforlogging.saidaninterviewee. 1Whichofthefollowingcanreplacetheunderlinedphrasetookmattersintohisownhands? A.calledonpeopletojoinhim B.appealedtopeopletogogreen. C.begantopickupthetrash. D.hadthecollectedtrashrecycled. 2LikeJeffHorowitzloggingtomanypeoplehasbecomeaanact. A.automatic. B.irresistible. C.arbitrary D.temporary 3WhatistheideathatLoggingeventsaremeanttopromote? A.loggingistrulybeneficial B.Trashcansshouldbewithinreach C.Litteringisnotacceptable. D.Communitiesshouldbekeptclean. 4Whatcanbeasuitabletitleforthepassage? A.NewExerciseEnjoysunbelievablepopularity B.NewExerciseTrendAlsoHelpsEnvironment C.Plogging﹣aFashionableWaytoclearwaste D.Plogging﹣anExerciseOriginatinginSweden
“调控植物生长﹣﹣代谢平衡实现可持续农业发展”入选2018年度中国科学十大进展其研究证实DELLA蛋白通过阻遏某些基因的转录从而抑制植物生长发育.而赤霉素能解除细胞中已经存在的DELLA蛋白的阻遏效果.以下叙述不合理的是
某生物兴趣小组希望通过遗传学杂交实验探究一些遗传学问题他们获得了稳定遗传的高茎黄粒品系1和矮茎白粒品系2两种玉米高茎A对矮茎a为显性白粒B对黄粒b为显性已知两对基因均位于常染色体上不考虑交叉互换. 1探究的问题 控制这两对相对性状的基因是否位于一对同源染色体上. 2请设计一组最简单的实验方案探究上述遗传学问题 ①观察和统计F1的性状及比例保留部分F1种子. ②观察和统计F2的性状及比例. 3实验分析 ①如果F2中表现型与比例为则控制这两对相对性状的基因不位于一对同源染色体上. ②如果F2中表现型与比例为则控制这两对相对性状的基因位于一对同源染色体上且基因连锁.
实施乡村振兴战略是建设美丽中国的关键我国是世界第一的鹅养殖大国约占世界出栏量的90%快速识别刚孵化的雏鹅性别对规模化养殖至关重要.某白鹅品种甲刚孵化出来的维鹅绒羽通常呈黄色或浅褐色饲养9个月后雏鹅性成熟绒羽退尽换上新羽羽色都是白色.科学家在繁育过程中选择成年10月龄公鹅40只母鹅200只进行混群饲养随机交配孵化获得1个批次的雏鹅G1观察雏鹅的绒羽和性别统计结果如下.请回答 1同一只鹅的雏鹅的绒羽羽色与成体的羽色有很大差异这说明控制羽色的基因羽毛的差异是基因选择性表达的结果. 2据表推测白鹅品种甲的雏鹅绒羽颜色为显性性状推测绒羽颜色遗传最可能是伴性遗传的理由是. 3为进一步确定白鹅品种甲的绒羽颜色的遗传方式从该批次白鹅G1中选取雏期绒羽颜色为的公鹅和的母鹅进行杂交实验通过子一代F1的绒羽色和性别进行确认若F1中则说明控制绒羽色的基因只在Z染色体上且能快速分辨雏鹅性别. 4若以上分析正确第1批次G1的母鹅中浅褐色绒羽的基因频率是推算依据是.
我国科技人员创造了浮床生态工艺法净化生活污水含有机物和无机物在水域中固定浮床上种植特殊的水生半水生植物以吸收水中的氮磷等元素.回答下列问题 1流经该水域生态系统的总能量是. 2生活污水流入水域中通过物理沉降化学分解和使污水得到净化.若流入该水域的生活污水过量则会导致生态系统遭到破坏原因是. 3浮床生态工艺法还能抑制藻类的繁殖防止“水华”发生原因是.答两点即可
为了研究水生生物对富营养化水体中磷的去除作用研究人员从某城市内河中取水样分别设置水葫芦鲢鱼“水葫芦+鲢鱼”等不同处理组进行实验分别取样检测水体中总磷浓度变化结果如图.下列相关叙述错误的是
下列有关生物学实验操作正确的有 ①探究温度对酶活性的影响可选择过氧化氢溶液作底物 ②在电子显微镜下拍摄到的叶绿体的结构照片属于物理模型 ③在花生子叶薄片上滴加苏丹III染液发现满视野都呈现橘黄色于是滴1﹣2滴50%酒精洗去浮色 ④在模拟细胞大小与物质运输的关系时琼脂块表面积和体积之比是自变量氢氧化钠扩散速度是因变量 ⑤用无水乙醇对绿叶中的色素进行提取和分离溶解度越大的色素在滤纸条上扩散速度越快 ⑥在观察细胞内DNA和RNA分布的实验中可使用酒精来改变细胞膜通透性加速染色剂进入细胞.
7.5分Peopletendtoacceptgroup'sstandardsofbehaviorandthinkinginagroupwork.Manyillustrations例证couldbegivenofthisfromeverydaylifebutwhatisofparticularinteresttopsychologistsishowmuchpeople'sjudgmentsandopinionscanbechangedasaresultofgrouppressure.Aschandothersnoticedthatpeopleinagroupwillagreetostatementsthatarecontrarytotheevidenceoftheirsenses.Itwouldbeamistaketothinkthatonlyparticularchangeablepeoplearechosentotakepartinexperimentsofthistype.Usuallyhighlyintelligentandindependentpeopleareused. Inatypicalexperimentthisiswhatmayhappen.Theexperimenterasksforvolunteerstojoinagroupwhichisinvestigatingvisualsense.Theparticipantsarenotthereforeawareoftherealpurposeoftheexperiment.Eachvolunteeristakentoaroomwherehefindsagroupofaboutsevenpeoplewhoarecooperatingwiththeexperimenter.Thegroupisshownastandardcardwhichcontainsasingleline.Theyarethenaskedtolookatasecondcard.Thishasthreelinesonit.Oneisobviouslylongerthanthelineonthefirstcardoneisshorterandonethesamelength.Theyhavetosaywhichlineonthesecondcardisthesamelengthasthelineonthestandardcard.Theothermembersofthegroupanswerfirstbuttwhatthevolunteerdoesnotknowisthattheyhavebeentoldtopickoneofthewronglines.Whenhis turncomesheisfacedwiththeconsistentopinionoftherestofthegroup﹣alltheothershavechosenlineAbuthequiteclearlyseeslineBascorrect. Whatwillhedo?AccordingtoAschmorethanhalfofthevictimschosenwillchangetheiropinion.Whatisequallysurprisingisthatwheninterviewedabouttheiranswersmostexplainedthattheyknowthegroupchoicewasincorrectbutthattheyyieldtothepressureofthegroupbecausetheythoughttheymustbesufferingfromanopticalillusion视觉假象orbecausetheywereafraidofbeingdifferent. 1Thepsychologistsareespeciallyinterestedin. A.theevidenceoftheexperiment B.thechangesintheattitudesofpeople C.thedifferenceinpeople'sbehavior D.thedegreeofchangesofpeople'sopinions 2Whymorethanhalfofthevictimschangestheiropinionsintheexperiment? A.Becausetheyhadbeentoldabouttheanswer. B.Becausethoughtthegroupchoicewascorrect. C.Becausetheysubmittedtothegrouppressure. D.Becausetheireyesweresufferingfromillusion. 3Thepurposeoftheauthorinwritingthispassageisto. A.illustratetheinfluenceofgrouppressureonindividuals B.encouragepeopletoactagainstanygroup'sopinion C.invitemorevolunteerstojoininAsch'sexperiment D.tellthereadershowtoperformpsychologicalexperiment
胰腺是哺乳动物重要器官科学家用胰腺进行科学实验探究其重要功能.请回答 1斯他林和贝利斯剪取狗小肠并刮下黏膜将黏膜与稀盐酸混合加砂子磨碎制成提取液发现提取液可促进胰腺分泌胰液.该实验验证的假设是. 2胰腺中大部分是胰腺细胞其间散布着胰岛胰岛A细胞和胰岛B细胞分布其中其分布方式为填“胰岛A细胞胰岛B细胞分别集群形成胰岛”/“胰岛A细胞胰岛B细胞及其他细胞混合集群形成胰岛”. 3胰腺中分泌的胰高血糖素与肝细胞膜上的受体结合后调节糖代谢过程这反映了细胞膜具有的功能.人体内需要胰腺源源不断地分泌胰岛素以维持激素含量动态平衡的原因是. 4科学家在豚鼠胰腺腺泡细胞中注射3H标记的亮氨酸并破坏了腺泡细胞中全部的高尔基体检测放射性的聚集和转移情况.结果发现放射性只在细胞内进行转移但却未出现在细胞外这表明.
热门题库
更多
高三上学期数学
高一下学期英语
教案备课库
高一上学期生物
高一下学期生物
高二上学期数学
高二上学期物理
高二上学期英语
高二上学期生物
高二下学期数学
高二上学期化学
高二下学期物理
高三下学期物理
高三上学期物理
高三上学期生物
高三上学期化学