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
The livelihood of each species in the vast and intricate assemblage of living things depends on the existences of other organism
The livelihood of each species in the vast and intricate assemblage of living things depends on the existences of other organism
admin
2016-10-24
55
问题
The livelihood of each species in the vast and intricate assemblage of living things depends on the existences of other organisms. This interdependence is sometimes subtle, sometimes obvious. Perhaps the most straightforward dependence of one species on another occurs with parasites, organisms that live on or in other living things and derive nutrients directly from them. The parasitic way of life is widespread. A multitude of microorganisms(including viruses and bacteria)and an army of invertebrates—or creatures lacking a spinal column(including crustaceans, insects, and many different types of worms)make their livings directly at the expense of other creatures. In the face of this onslaught, living things have evolved a variety of defense mechanisms for protecting their bodies from invasion by other organisms.
Certain fungi and even some kinds of bacteria secrete substances known as antibiotics into their external environment. These substances are capable of killing or inhibiting the growth of various kinds of bacteria that also occupy the area, thereby eliminating or reducing the competition for nutrients. The same principle is used in defense against invaders in other groups of organisms. For example, when attacked by disease-causing fungi or bacteria, many kinds of plants produce chemicals that help to ward off the invaders.
Members of the animal kingdom have developed a variety of defense mechanisms for dealing with parasites. Although these mechanisms vary considerably, all major groups of animals are capable of detecting and reacting to the presence of "foreign" cells. In fact, throughout the animal kingdom, from sponges to certain types of worms, shellfish, and all vertebrates(creatures possessing a spinal column), there is evidence that transplants of cells or fragments of tissues into an animal are accepted only if they come from genetically compatible or closely related individuals.
The ability to distinguish between "self" and "nonself", while present in all animals, is most efficient among vertebrates, which have developed an immune system as their defense mechanism. The immune system recognizes and takes action against foreign invaders and transplanted tissues that are treated as foreign cells.
According to the passage, a transplant of tissue between genetically incompatible organisms will result in the transplanted tissue ______.
选项
A、becoming a parasite
B、being treated as an invader
C、altering its genetic makeup
D、developing a new immune system
答案
B
解析
根据短文.在基因不相容的生物之间移植一些组织会导致经受移植的组织被视为入侵者。根据第三段最后一句,有证据表明,只有当被移植的细胞或零碎的组织源于基因相容的或彼此有亲缘关系的个体,将细胞或组织植入动物的体内是可以接受的。
转载请注明原文地址:https://kaotiyun.com/show/JCGO777K
0
考博英语
相关试题推荐
AstheEnglishlanguagehaschangedatafastspeedinthelastcentury,sohastheuseoftheEnglishlanguage.AftertheB
Thereareseveral______betweentheoriginalestimatesofthecostandtheactualbills.
Readingbooksisahabitthatispopularly【C1】______bymoreandmorepeople.Itbenefitsourlivesbyimprovingourknowledgeto
Readingbooksisahabitthatispopularly【C1】______bymoreandmorepeople.Itbenefitsourlivesbyimprovingourknowledgeto
Schoolbuildingsthemselvescanreflectliberalorconservativeviewsaboutwhatshouldgooninaclassroom.Theearliestschoo
InChristianwritersitisnaturalthatlogicalexplanationsofthegenerallawofstormsshouldcenterabouttheDevil.Clement
这次到台湾访问交流,虽然行色匆匆,但是,看了不少地方,访了旧友,交了新知,大家走到一起,谈论的一个重要话题就是中华民族在21世纪的强盛。虽然祖国大陆、台湾的青年生活在不同的社会环境中,有着各自不同的生活经历,但大家的内心都深深铭刻着中华文化优秀传统的印记,
一个母亲如果没有文化,很难担负教育好下一代的责任。占中国人口半数的妇女的文化素质提不高,全民族的文化素质也难提高。
A、possibilityB、perspectiveC、occurrenceD、opportunityApossibility意为“可能性”;perspective意为“观点,看法”;occurrence意为“事情,发生,出现”;opportuni
随机试题
工业企业在计划期内生产的符合质量的工业产品的实物量叫产品质量。()
以下为心肌灌注显像的临床应用范围,但应除外
根据有关规定,必须成立药事管理与药物治疗学委员会的是
当开发项目用地面积一定时,决定项目可建筑面积数量的是()。
根据招标投标相关法律规定,在投标有效期结束前,由于出现特殊情况,招标人要求投标人延长投标有效期时()
纳税人发生纳税义务,未按照税法规定的期限办理纳税申报,经税务机关责令限期申报,逾期仍未申报的,税务机关有权核定其应缴纳税额。()
下列属于演示技能作用的是()。
设有一个直接映像方式的Cache,其容量为8KB,每块的大小为16B,主存的容量为512KB,试回答以下问题:该Cache可容纳多少个块?Cache字地址有多少位?块号和块内地址各多少位?
theBeijingOlympicMascots
ITU标准OC-24和OC-12的传输速率分别为()。
最新回复
(
0
)