首页
财务会计
医药卫生
金融经济
考公考编
外语考试
学历提升
职称考试
建筑工程
IT考试
其他
登录
职称考试
共用题干 第一篇Immune FunctionsThe immune system is equal in complexity to the comb...
共用题干 第一篇Immune FunctionsThe immune system is equal in complexity to the comb...
admin
2020-12-24
34
问题
共用题干
第一篇
Immune Functions
The immune system is equal in complexity to the combined intricacies of the brain and nervous system.
The success of the immune system in defending the body relies on a dynamic regulatory communication net-
work consisting of millions and millions of cells.Organized into sets and subsets,these cells pass information
back and forth like clouds of bees flying around a hive(蜂巢).The result is a sensitive system of checks and
balances that produces an immune response that is prompt,appropriate,effective,and self-limiting.
At the heart of the immune system is the ability to distinguish between self and nonself. When immune
defenders encounter cells or organisms carrying foreign or nonself molecules,the immune troops move quickly
to eliminate the intruders(人侵者).Virtually every body cell carries distinctive molecules that identify it as
self. The body's immune defenses do not normally attack tissues that carry a self-marker. Rather,immune
cells and other body cells coexist peaceably in a state known as self-tolerance.When a normally functioning
immune system attacks a nonself molecule,the system has the ability to"remember"the specifics of the
foreign body.Upon subsequent encounters with the same species of molecules,the immune system reacts
accordingly. With the possible exception of antibodies(抗体)passed during lactation(授乳期), this so
called immune system memory is not inherited.Despite the occurrence of a virus in your family,your immune
system must"learn"from experience with the many millions of distinctive nonseif molecules in the sea of
microbes(微生物)in which we live. Learning entails producing the appropriate molecules and cells to match
up with and counteract each nonseif invader.
Any substance capable of triggering an immune response is called an antigen(抗原).Antigens are not
to be confused with illergens(过敏原),which are most often harmless substances that provoke the immune
system to set off the inappropriate and harmful response known as allergy.An antigen can be a virus,a bacte-
rium,or even a portion or product of one of these organisms.Tissues or cells from another individual also act
as antigens,because the immune system recognizes transplanted tissues as foreign,it rejects them.The body
will even reject nourishing proteins unless they are first broken down by the digestive system into their
primary,nonantigenic building blocks.An antigen announces its foreignness by means of intricate and charac-
teristic shapes called epitopes(抗原表位), which protrude(突出)from its surface. Most antigens , even the
simplest microbes,carry several different kinds of epitopes on their surface;some may even carry several
hundreds.Some epitopes will be more effective than others at stimulating an immune response.Only in abnormal
situations does the immune system wrongly identify self as nonself and execute a misdirected immune attack.
选项
What is used to describe the communication network consisting of cells in the immune system?
A:The immune system's memory.
B:Immune troops sliminating intruders.
C:Bees flying around a hive.
D:A sea of microbes.
答案
C
解析
由第一段第三句中的“like clouds of bees flying around a hive”可知选B。
由文章第二段第五句可知答案为A。
由文章最后一段中的“An antigen announces its foreignness by …characteristic shapes …" 可知选C。
由文章最后一段第一句可知,能引起免疫反应的物质叫抗原,即抗原能引起免疫反应, 故选B
由文章第二段第一句“At the heart of the immune system...”可知选D。 heart相当 于basic。
转载请注明原文地址:https://ti.zuoweng.com/ti/MG9QKKKQ
相关试题推荐
共用题干 UrbanizationandItsInfluenceOverhalftheworld'speoplenowlivein...
共用题干 UrbanizationandItsInfluenceOverhalftheworld'speoplenowlivein...
共用题干 UrbanizationandItsInfluenceOverhalftheworld'speoplenowlivein...
共用题干 UrbanizationandItsInfluenceOverhalftheworld'speoplenowlivein...
共用题干 UrbanizationandItsInfluenceOverhalftheworld'speoplenowlivein...
共用题干 AmericanDreamsThereisacommonresponsetoAmericaamongforeignwrit...
共用题干 AmericanDreamsThereisacommonresponsetoAmericaamongforeignwrit...
共用题干 第三篇Internetshoppingisanewwayofshopping.Nowadays,youcanshopfo...
共用题干 第三篇Internetshoppingisanewwayofshopping.Nowadays,youcanshopfo...
共用题干 第三篇Internetshoppingisanewwayofshopping.Nowadays,youcanshopfo...
随机试题
陕西历史博物馆收藏的国宝级文物中,属于西汉的是( )。 A、镶金兽首玛瑙杯
(5-9题共用备选答案) A.多巴胺受体 B.乙酰胆碱受体 C.5-羟色胺
根据《关于加强关于水力工程建设项目开工管理工作的通知》(水建管[2006]144
下列指标中用于鉴别原发性与继发性甲状腺功能减退症的是 A.TSH B.TT3
下列有关防火分区面积的说法中,正确的是()。
马克思主义伦理学认为,道德是依靠()来调整人与人之间、个人与社会之间以及
将各类方案的各种因素进行综合考虑比较,从中选择大部分(或主要)因素比较好的方案,这种项目规模评估方法称为( )。A.效益成本评比法B.多因素评比法C.最低
名词解释-学习动机
关于颞下颌关节脱位的诊断哪一项是错误的()A.关系紊乱B.双侧脱位可能出现疼痛C.大张口运动后不能自行闭合D.开闭口在关节窝内均能扪及髁突E
下列工程建设项目中,除()以外均属于依法必须招标的范围。A.关系社会公共利益和安全的基础设施项目B.关系公众利益和安全的公用事业项目C.使用国有企业事业单位