考研英语作文：CellsandTemperature.docx

考研英语作文：CellsandTemperature

在现实生活或工作学习中，大家都接触过作文吧，作文是人们把记忆中所存储的有关知识、经验和思想用书面形式表达出来的记叙方式。还是对作文一筹莫展吗？下面是小编收集整理的'考研英语作文：CellsandTemperature，供大家参考借鉴，希望可以帮助到有需要的朋友。cellscannotremainaliveoutsidecertainlimitsoftemperatureandmuchnarrowerlimitsmarktheboundariesofeffectivefunctioning.enzymesystemsofmammalsandbirdsaremostefficientonlywithinanarrowrangearound37c;adepartureofafewdegreesfromthisvalueseriouslyimpairstheirfunctioning.eventhoughcellscansurvivewiderfluctuationstheintegratedactionsofbodilysystemsareimpaired.otheranimalshaveawidertoleranceforchangesofbodilytemperature.forcenturiesithasbeenrecognizedthatmammalsandbirdsdifferfromotheranimalsinthewaytheyregulatebodytemperature.waysofcharacterizingthedifferencehavebecomemoreaccurateandmeaningfulovertime,butpopularterminologystillreflectstheoldpisionintowarm-bloodedandcold-bloodedspecies;warm-bloodedincludedmammalsandbirdswhereasallothercreatureswereconsideredcold-blooded.asmorespecieswerestudied,itbecameevidentthatthisclassificationwasinadequate.afencelizardoradesertiguana-eachcold-blooded----usuallyhasabodytemperatureonlyadegreeortwobelowthatofhumansandsoisnotcold.thereforethenetdistinctionwasmadebetweenanimalsthatmaintainaconstantbodytemperature,calledhome0therms,andthosewhosebodytemperaturevarieswiththeirenvironments,calledpoikilotherms.butthisclassificationalsoprovedinadequate,becauseamongmammalstherearemanythatvarytheirbodytemperaturesduringhibernation.furthermore,manyinvertebratesthatliveinthedepthsoftheoceannevereperiencechangeinthedepthsoftheoceannevereperiencechangeinthechillofthedeepwater,andtheirbodytemperaturesremainconstant.