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
专升本
Imagine an animal that becomes frozen in cold weather. Then, when it gets warmer, the animal simply unfreezes and goes back to i
Imagine an animal that becomes frozen in cold weather. Then, when it gets warmer, the animal simply unfreezes and goes back to i
admin
2018-04-13
65
问题
Imagine an animal that becomes frozen in cold weather. Then, when it gets warmer, the animal simply unfreezes and goes back to it$ normal life. Although this may sound like something from a science-fiction movie, it is exactly what happens to the wood frog over winter and spring. When winter begins, the frog, which is found throughout much of Canada, buries itself in leaves and dirt.
As the ground begins to freeze, so does the frog’ s body.
Normally, if a living creature is frozen, the cells inside its body are destroyed, leading to death. How, then, does the wood frog survive? The secret lies in the fact that although the water between the cells in the frog’ s body becomes frozen, the water inside the cells does not freeze. Before the winter begins, the frog stores starch in its body. As the weather gets colder, the drop in temperature causes the frog’s body to change this starch into glucose (葡萄糖). This glucose, in turn, lowers the temperature at which the liquid inside the frog’ s cells freezes. As a result, the cells do not freeze even at very low temperatures, allowing the frog to stay alive. Some wood frogs stay in this frozen state—with their hearts stopped completely—for months without harm.
Now researchers are hoping to adapt the wood frog’ s secret to help them preserve human organs for transplants. Currently, after organs are removed from a donor’ s body, they are packed in a special liquid and kept very cold. However, they cannot be frozen because the ice would damage the cells in the organs. For this reason, the organs must be used quickly. If doctors had a way to preserve organs longer, they would have more time to find the best matches among people waiting for organ transplants.
There is still a lot about the wood frog that scientists do not understand. They still have to work out, for example, exactly how the frog is able to unfreeze itself and what actually restarts the frog’ s heart when the weather becomes warmer. What is clear, however, is that lessons learned by studying this tiny creature could be of great benefit to humans in the near future.
Which is one thing that scientists would like to find out about the wood frog?
选项
A、Whether it becomes frozen in the spring.
B、How its heart starts again when it unfreezes.
C、Which parts of its body freeze in cold weather.
D、Why it takes so long to unfreeze at the end of winter.
答案
B
解析
事实细节题。根据最后一段第二句可知,答案为B。
转载请注明原文地址:https://kaotiyun.com/show/scWC777K
本试题收录于:
英语题库普高专升本分类
0
英语
普高专升本
相关试题推荐
Actingissuchanover-crowdedprofessionthattheonlyadvicethatshouldbegiventoayoungpersonthinkingofgoingonthes
Lifestyleisthewayapersonlives;itincludeswork,leisuretime,hobbies,otherinterests,andpersonalphilosophy.Oneperso
ResearchersattheUniversityofMaryland’sSchoolofNursingfoundthat55percentofthe2,103femalenursestheysurveyedwe
Nowputonsunscreen(防晒霜)Somesunscreenspreventsunburnbutnotothertypesofskindamage.Makesureyoursoffersabroadrang
Acoeducational(男女合校的)schoolofferschildrennothinglessthanatreeversionofsocietyinminiature(缩影).Boysandgirlsaregi
Acoeducational(男女合校的)schoolofferschildrennothinglessthanatreeversionofsocietyinminiature(缩影).Boysandgirlsaregi
Economictheorypredictstheresultsofeconomicdecisionssuchasdecisionsaboutfarmproduction,rentcontrol,andtheminimu
GeorgeMarkovwasafamouswriterinBulgaria.In1969hesuspectedthathewasgoingtobeimprisonedorkilledbecauseoneof
A、Themanwasreading.B、Themanwastalking.C、Themanwassmiling.D、Themanwassleeping.D
随机试题
提倡终身教育的学者是法国的()。
关于心室肌Ca2+通道的叙述,错误的是
A.遍多酸B.吡哆醛C.两者都是D.两者都不是(1991年)构成辅酶A的是
患者,男,20岁。3~4天来寒战、高热、咳嗽,咳少许黏痰,略带血。因气急、发绀、休克死亡。病理切片见肺泡内充满红、白细胞和浆液性渗出,但肺泡壁尚完整,最可能的诊断为
进行现况调查时。调查时间一般为
患者咳嗽气喘,痰稀色白,形寒肢冷,舌淡苔白,脉迟,属于( )。
项目准备阶段的融资咨询应考虑的内容包括项目财务风险最低及()。
设A是三阶矩阵,α1,α2,α3为三个三维线性无关的列向量,且满足Aα1=α2+α3,Aα2=α1+α3,Aα3=α1+α2判断矩阵A可否对角化.
AwaronsugarhasbegunintheUKthatechoesthenation’ssuccessfulcampaignagainstsalt.Theeffortis【C1】______becauseit
PerhapsthemostspectacularfeatureoftheGrandCanyon,itsRedwalllimestonecliff,standsabouthalfwayupthechasmandis
最新回复
(
0
)