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
Despite the fact that today virus are known to cause cancer in animals and in plants, there exists a great reluctance to accept
Despite the fact that today virus are known to cause cancer in animals and in plants, there exists a great reluctance to accept
admin
2014-01-13
67
问题
Despite the fact that today virus are known to cause cancer in animals and in plants, there exists a great reluctance to accept viruses as being of importance in human cancer. Basic biological phenomena generally do not differ strikingly as one goes from one species to another. It should be recognized that cancer is a biological problem and not a problem that is unique for man. Cancer originates when a normal cell suddenly becomes a cancer which multiplies widely and without apparent restraint. Cancer may originate in many different kinds of cell, but the cancer cell usually continues to carry certain traits of the cell of origin. The transformation of a normal cell into a cancer cell may have more than one kind of cause, but there is good reason to consider the relationships that exist between viruses and cancer.
Since there is no evidence that human cancer, as generally experienced, is infectious, many persons believe that because viruses are infectious agents they cannot possibly be of importance in human cancer. However, viruses can mutate and examples are known in which a virus that never kills its host can mutate to form a new strain of virus that always kills its host. It does not seem unreasonable to assume that an innocuous latent virus might mutate to form a strain that causes cancer. Certainly the experimental evidence now available is consistent with the idea that viruses as we know them today could be the causative agents of most, if not all cancer, including cancer in man.
What is the passage mainly about?
选项
A、Viruses are the causative agents of most cancer.
B、How and why viruses mutate.
C、Basic biological phenomena in plants, animals and man.
D、Why the human cancer is not infectious.
答案
A
解析
文章开头部分说病毒是导致动植物癌症的主要原因,后文又继续补充它也是人类癌症的重要原因。由此可知,病毒是大多数癌症的病原体。据此判断,本题选A。
转载请注明原文地址:https://kaotiyun.com/show/qIQO777K
0
考博英语
相关试题推荐
Forlaymenethnologyisprobablythemostinterestingofthebiologicalsciencesfortheveryreasonthatitconcernsanimalsin
1.Thesinglelongastockfigureinstories,songsandpersonalads.wastraditionallysomeoneatthemarginsofsociety:afigu
1.Thesinglelongastockfigureinstories,songsandpersonalads.wastraditionallysomeoneatthemarginsofsociety:afigu
Shouldwecareifover150knownspeciesofanimalshave【1】fromtheearthinthelastfiftyyears?Shouldwebeconcernedthatt
Shouldwecareifover150knownspeciesofanimalshave【1】fromtheearthinthelastfiftyyears?Shouldwebeconcernedthatt
Shouldwecareifover150knownspeciesofanimalshave【1】fromtheearthinthelastfiftyyears?Shouldwebeconcernedthatt
Shouldwecareifover150knownspeciesofanimalshave【1】fromtheearthinthelastfiftyyears?Shouldwebeconcernedthatt
Shouldwecareifover150knownspeciesofanimalshave【1】fromtheearthinthelastfiftyyears?Shouldwebeconcernedthatt
Shouldwecareifover150knownspeciesofanimalshave【1】fromtheearthinthelastfiftyyears?Shouldwebeconcernedthatt
随机试题
社会工作者在对社会服务方案进行过程评估时最关注()。
《北风吹》源自河北民歌()。
A、 B、 C、 D、 C此题答案为C。第一组的三个图形线条数均为13,第二组的图形线条数均为14,选项中只有C项的线条数是14。故答案选C。
居民服务业中,城镇非私营单位就业人员比私营单位就业人员人均收入约高:()
法律后果可以分为()。
核心价值体系和核心价值观,是决定文化性质和方向的最深层次要素,是一个国家的重要稳定器。社会主义核心价值体系的主要内容包括()
经济计量分析的工作程序依次是(69)。
设有关键码序列(Q,G,M,Z,A,N,B,P,X,H,Y,S,T,L,K,E),采用二路归并排序法进行排序,下面哪一个序列是第二趟归并后的结果?
Lifereallyshouldbeonelongjourneyofjoyforchildrenbornwithaworldofwealthattheirfeet.Internationallyfamous
Itisnotsurprising,【C1】______thelackoffitbetweengiftedstudentsandtheirschools,thatsuchstudentsoftenhavelittleg
最新回复
(
0
)