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
A new biotechnology procedure that could become commercially available in as little as two to four years is "transgenosis", whic
A new biotechnology procedure that could become commercially available in as little as two to four years is "transgenosis", whic
admin
2017-03-25
41
问题
A new biotechnology procedure that could become commercially available in as little as two to four years is "transgenosis", which permits scientists to create an animal with specific traits by adding, removing, inactivating, or repairing genes in an embryo. The additional genes can come from any source. For example, if a gene of interest occurs in mosquitoes—say, one that codes for resistance to a certain disease—it can be removed and placed in the embryo of a farm animal, the several strains of commercially useful transgenic farm animals that will probably emerge in the next few years could include leaner pigs, poultry resisting to influenza or other deadly diseases, sheep with wool that is easier to wash, and goats that produce valuable pharmaceuticals in their milk.
The simplest way to make transgenic animals is to inject a gene into a one-cell embryo and then implant the embryo in another animal. Under the right conditions, the new gene joins one of the embryo’s strands of genes. Each cell created as the embryo divides gets a copy of the new gene. An alternative technique is to incorporate the gene into a type of virus known as a retrovirus that has been modified so it cannot reproduce itself after entering a cell. The virus, which cannot cause disease, delivers the gene to the cell’s nucleus. Often this method is better than gene injection because a retrovirus always delivers just one gene, and the gene is always undamaged and complete.
The tone of this passage is______.
选项
A、critical
B、factual
C、humorous
D、romantic
答案
B
解析
本文作者没有表示任何观点,只对转基因技术做简单介绍,因此“factual,实际的”是正确答案,其他三项“critical批判的;humorous幽默的;romantic浪漫的”都不正确。
转载请注明原文地址:https://jikaoti.com/ti/xzyYFFFM
0
考博英语
相关试题推荐
Aschildrenwestart【C1】______anaturalcuriosityabouteverythingaroundus,andduringthematurationprocessthiscuriosityc
Tomanagerhopingtoblossomasabusinessleadermustdeveloptheskilltocommunicateeffectively.Oneoftheforemosttaskso
Theincreaseinglobaltrademeansthatinternationalcompaniescannotaffordtomakecostlyadvertisingmistakesiftheywantt
Internationalsportshouldcreategoodwillbetweenthenations,butinthepresentorganizationoftheOlympicssomehowencourag
Einsteinwasamandeeply______totheidealofthemorallyresponsiblescientist.
Somepractical______isdesirableforcandidatesinterestedinapplyingforthisjob.
Tosurviveintheintensetradecompetitionbetweencountries,companiesmust______thequalitiesandvarietiesoftheirproducts
Changesinthevolumeofunemploymentaregovernedbythreefundamentalforces:thegrowthofthelaborforce,theincreaseino
Theyearsbetween1870and1895broughtenormouschangestothetheaterintheUnitedStatesastheresidentcompanywasundermi
TheBritishpublicwasslowlyeasedintotheknowledgethatwhathadbeenseenasafairytalemarriagehasbeenAdeeplymiserabl
随机试题
患儿,男,3岁。超声显示肝脏增大,形态失常,右叶可见一1.4cm×16cm大小的实性强回声团块,边界清楚,内回声不均匀,内可见强光团,后伴声影,最可能的诊断是
大脑动脉环不包括
A.高温试验 B.高湿度试验 C.强光照射试验 D.加速试验 E.长期试验是在接近药品的实际贮存条件(温度25℃±2℃,相对湿度75%±5%)下进行,其目的是为了制订药物的有效期提供依据
作为FIDIC附属会员或支持会员的国家有()。
哪些建筑可不设室内消火栓系统?
党的十四大明确提出我国经济体制改革的目标是建立社会主义市场经济体制,以利于进一步解放和发展生产力。()
随机变量X的概率分布表如下:
单位组织迎新座谈会,需要采购一些水果,领导暗示你到他的一位朋友那里采购。但是你去他朋友那边发现水果不新鲜,质量也不好,这个时候你会怎么办?
Therearetwobasicsortsofvisualperspective—aerialperspectiveandlinearperspective.Aerialperspective—and"aerial"just
【S1】【S3】
最新回复
(
0
)