首页
登录
职称英语
A new biotechnology procedure that could become commercially available in as
A new biotechnology procedure that could become commercially available in as
游客
2025-04-16
30
管理
问题
A new biotechnology procedure that could become commercially available in as little as two to four years is "transgenesis", 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 places 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. [br] The tone of this passage is ______.
选项
A、critical
B、factual
C、humorous
D、romantic
答案
B
解析
critical,批判的;factual,实际的;humorous,幽默的;romantic,浪漫的。文中作者没有表示任何观点,只对转基因技术做简单介绍,所以选B。
转载请注明原文地址:http://tihaiku.com/zcyy/4040162.html
相关试题推荐
Anewbiotechnologyprocedurethatcouldbecomecommerciallyavailableinas
Mostpeoplewouldbeimpressedbythehighqualityofmedicineavailableto
Mostpeoplewouldbeimpressedbythehighqualityofmedicineavailableto
Mostpeoplewouldbeimpressedbythehighqualityofmedicineavailableto
Mostpeoplewouldbeimpressedbythehighqualityofmedicineavailableto
AnintelligentTVviewermayoccasionallybecomeenragedbythe______argumenta
Here,soprofligatehasitsusebecometheairconditionerisalmost______theau
Onceapictureisprovedtobeaforgery,itbecomesquite______.(中南大学2007年试题)A、
The______choiceforaconsumer,therefore,isthechoiceamongtheavailableone
Whowouldhavethoughtwewouldbecomeaplanetof"ologies"?There’sbiolog
随机试题
Normallyastudentmustattendacertainnumberofcoursesinordertogradua
文化因素影响健康的途径。
-____willhestayinthiscity? -Atle
A.1.33kW B.2.77kW C.3.47kW D.7.53kW
A.0V B.2V C.6V D.10V
存在于豆类食物中的寡糖主要是( )。A.半乳糖 B.乳糖 C.糊精 D.
房地产经纪机构为买卖双方提供房地产产权登记代办服务时,需注意().A:房地产经纪
根据《建设工程价款结算暂行办法》,关于设计变更价款调整规定的说法,正确的是()。
(2019年真题)华泰医药公司拟在J国建立一个药品研发和生产基地,并对该国的相关
下列事项中,单位开户银行可以使用现金的有()。A:发给公司甲某的800元奖金B
最新回复
(
0
)