首页
登录
职称英语
Homeostasis, an animal’s maintenance of certain internal variables within an
Homeostasis, an animal’s maintenance of certain internal variables within an
游客
2024-01-13
29
管理
问题
Homeostasis, an animal’s maintenance of certain internal variables within an acceptable range,particularly in extreme physical environments, has long interested biologists. The desert rat andthe camel in the most water-deprived environments, and marine vertebrates in an all-waterenvironment, encounter the same regulatory problem: maintaining adequate internal fluid balance.
For desert rats and camels, the problem is conservation of water in an environment where standingwater is nonexistent, temperature is high, and humidity is low. Despite these handicaps, desert ratsare able to maintain the osmotic pressure of their blood, as well as their total boy-water content, atapproximately the same levels as other rats. One countermeasure is behavioral: these rats stay inburrows during the hot part of the day, thus avoiding loss of fluid through panting or sweating,which are regulatory mechanisms for maintaining internal body temperature by evaporativecooling. Also, desert rats’ kidneys can excrete a urine having twice as high a salt content as seawater.
Marine vertebrates experience difficulty with their water balance because though there is noshortage of seawater to drink, they must drink a lot of it to maintain their internal fluid balance.But the excess salts from the seawater must be discharged somehow, and the kidneys of mostmarine vertebrates are unable to excrete a urine in which the salts are more concentrated than inseawater. Most of these animals have special salt-secreting organs outside the kidney that enablethem to eliminate excess salt.
选项
A、To compare two different approaches to the study of homeostasis
B、To summarize the findings of several studies regarding organisms’ maintenance of internal variables in extreme environments
C、To argue for a particular hypothesis regarding various organisms’ conservation of water in desert environments
D、To cite examples of how homeostasis is achieved by various organisms
E、To defend a new theory regarding the maintenance of adeuate fluid balance
答案
D
解析
This question asks you to identify the primary concern of the passage. The best answer is D. The passage focuses primarily on a discussion of how various animals achieve homeostasis. Choice A is not correct: while the passage does discuss the regulatory mechanisms employed by animals in two very different environments, it does not compare two different approaches to the study of those mechanisms. Choice B is not correct because no particular studies are cited in the passage. Choices C and E can be eliminated because the passage is concerned with a straightforward description of certain regulatory processes in various animals. It does not argue in favor of any particular hypothesis, nor does it defend any new theory concerning homeostasis.
转载请注明原文地址:https://tihaiku.com/zcyy/3359892.html
相关试题推荐
Fiftyyearsago,wealthypeoplelikedhuntingwildanimalsforfun______sightsee
Animalsseemtohavethesensetoeatwhentheyarehungryandtheydonote
Thatfamilyisalwaysquarrelling______themselves.A、withinB、betweenC、withD、am
Manychildrenchose"AnimalWorld"astheir______TVprogramme.A、favorB、favorite
Thenewpowerplantisreported______withinthreeyears.A、havingbeencompleted
Ican______youthattheanimalsarewellcaredforinourzoo,soyouneedn’two
Inasecondhandbookshop,Billycameacrossabookwhichhethoughtwascertain
Nomatterwhoyouareorwhereyoucomefrom,onethingiscertain:youarea
Nomatterwhoyouareorwhereyoucomefrom,onethingiscertain:youarea
Nomatterwhoyouareorwhereyoucomefrom,onethingiscertain:youarea
随机试题
[originaltext]Thecostisgoingupforjustabouteverything,andcolleget
[originaltext]M:WelcometoABCElectronics.First,letmegooverwhatwedoi
劳动者与用人单位发生劳动争议,应向当地()提出申述,要求补发所扣工资,并继续履行
A.两条沉淀线相交叉B.两条沉淀线相切C.两条弧线不连接D.无沉淀线E.两条沉淀
对建筑物进行抗震设防的设计时,根据以往的地震灾害的经验和科学研究成果首先进行(
根据《行政处罚法》,在下列行政处罚种类中,不属于地方性法规设定的行政处罚是()
下列可能给某商业银行带来声誉风险的有()。 A.关于银行高比例不良资产的媒体
一住店客人未付房钱即想离开旅馆去车站。旅馆服务员揪住他不让走,并打报警电话。客人
腻苔主病是A.湿浊 B.痰饮 C.瘀血 D.食积 E.中风
对于不同计价方式合同的风险,下列说法中正确的是()。A.承包商承担全部工程量和
最新回复
(
0
)