首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Studies of the Weddell seal in the laboratory have described the physiological mechanisms that allow the seal to cope with the e
Studies of the Weddell seal in the laboratory have described the physiological mechanisms that allow the seal to cope with the e
admin
2014-09-18
99
问题
Studies of the Weddell seal in the laboratory have described the physiological mechanisms that allow the seal to cope with the extreme oxygen depriva- tion that occurs during its longest dives, which can extend 500 meters below the ocean’ s surface and last for over 70 minutes. Recent field studies, however, suggest that during more typical dives in the wild, this seal’ s physiological behavior is different.
In the laboratory, when the seal dives below the surface of the water and stops breathing, its heart beats more slowly, requiring less oxygen, and its arteries become constricted, ensuring that the seal’ s blood remains concentrated near those organs most crucial to its ability to navigate underwater. The seal essentially shuts off the flow of blood to other organs, which either stop functioning until the seal surfaces or switch to an anaerobic(oxygen-independent)metabolism. The latter results in the production of large amounts of lactic acid which can adversely affect the PH of the seal’ s blood but since the anaerobic metabolism occurs only in those tissues which have been isolated from the seal’s blood supply, the lactic acid is released into the seal’ s blood only after the seal surfaces, when the lungs, liver, and other organs quickly clear the acid from the seal’s blood stream. Recent field studies, however, reveal that on dives in the wild, the seal usually heads directly for its prey and returns to the surface in less than twenty minutes. The absence of high levels of lactic acid in the seal’ s blood after such dives suggests that during them, the seal’ s organs do not resort to the anaerobic metabolism observed in the laboratory, but are supplied with oxy- gen from the blood. The seal’ s longer excursions underwater, during which it appears to be either exploring distant routes or evading a predator, do evoke the diving response seen in the laborato- ry. But why do the seal’ s laboratory dives always evoke this response, regardless of their length or depth? Some biologists speculate that because in laboratory dives the seal is forcibly sub- merged, it does not know how long it will remain underwater and so prepares for the worst.
The passage provides information to support which of the following generalizations?
选项
A、Observations of animals’ physiological behavior in the wild are not reliable unless verified by laboratory studies.
B、It is generally less difficult to observe the physiological behavior of an animal in the wild than in the laboratory.
C、The level of lactic acid in an animal’s blood is likely to be higher when it is searching for prey than when it is evading predators.
D、The level of lactic acid in an animal’s blood is likely to be lowest during those periods in which it experiences oxygen deprivation.
E、The physiological behavior of animals in a laboratory setting is not always consistent with their physiological behavior in the wild.
答案
E
解析
文章支持下列哪个观点?A.动物生理行为在野外的观察除非得到了实验室验证,否则是不可靠的。正好说反,原文海豹的潜水生理机制实验室中的观测结果是不完全的,要用野外观测来修正。B.“less difficult to observe”文中未涉及观察难度。C.“lactic acid in an animal’s blood”暂且不论此观点用在海豹身上对不对,就是正确也不能推广到泛指任意一种动物。D.同C。E.正确。动物的野外生理行为并不总和实验室中一致。此结论只要能有一例,就可以说是“not always consistent”,文中海豹就是这样一个例子。
转载请注明原文地址:https://kaotiyun.com/show/0ctO777K
本试题收录于:
GMAT VERBAL题库GMAT分类
0
GMAT VERBAL
GMAT
相关试题推荐
It’simportanttolocateindustriesinareaswhereasupplyofrawmaterialsis______.
In1947agroupoffamouspeoplefromtheartworldheadedbyanAustrianconductordecidedtoholdaninternationalfestivalof
LivinginthecentralAmericandeserthasitsproblems,______obtainingwaterisnottheleast.
Themind-successconnectionisstrong,andmanyobstaclestooursuccessarealsomental.Somepeoplerelymoreonfacts,while
Imagineaschoolthatexpecteditsstudentstobecomeliterate(有读写能力的)withoutanyformalinstruction.Mostparentswouldbeal
Howfitareyourteeth?Areyoulazyaboutbrushingthem?Neverfear:Aninventorisonthecase.Anelectrictoothbrushsenses
Manypeopleconsiderswitchingfromhomeschoolingtotraditionalschoolingasastudentgrowsolder,forreasonsincludingmore
Theydidnotfind______topreparefortheworstconditionstheymightmeet.
Extensivenewstudiessuggestthatdieworldhasmadeextraordinaryprogressinreducingpovertyinrecentdecades.Theresearch
随机试题
改错题:阅读短文,改正文中的文字、标点符号差错。“废墟”这两个字目前在我国绝大多数人的心目中还只是一个跟文化和美学不相干的贬意词。《现代汉语词典》对“废墟”的解释仅仅是“城市、村庄遭受破坏或灾害后变成的荒凉地方”;《辞海》的解释也是简单的一句:“
“把自己当作泥土吧/让众人把你踩成一条道路”,这诗句的作者是()
患者,20岁,骨折愈合良好。5年后骨折处骨组织病理变化表现为
欲描述某省2010年鼻咽癌患者的职业构成情况,宜绘制的统计图是
设计总负责单位利用自身的()经验,负责对设计的进度控制和质量控制,往往更有利于建设项目设计进度和质量目标的实现。
关于银行卡的说法正确的有()。
我国对非公有制经济的基本政策是严格限制数量和规模,保护其合法收入。()
在我国古代,气象学还不是一门成熟、独立的学科,但观测天气气候的变化,却是自古就有的人类科学活动之一。殷商时代的甲骨文里,就有文字记载气象方面的观测资料。古代最原始测风器主要用于测量风向。开始将布帛之类挂在竿上,后来改用鸡毛做成条形或扇形的羽葆,风吹羽葆扬,
法律义务是指法律关系主体()。
在SELECT命令中,使用ASC时必须配合使用的短语是()。
最新回复
(
0
)