首页
登录
职称英语
The genetic characteristics of all life forms on earth are embodied in the c
The genetic characteristics of all life forms on earth are embodied in the c
游客
2023-09-11
7
管理
问题
The genetic characteristics of all life forms on earth are embodied in the chemical structure of DNA molecules. An organism’s DNA molecules provide a complete blueprint for its physical makeup. Genetic engineering is the process of altering the DNA genetic code to change the characteristics of plants and animals. Through the process, scientists can literally build to order new life forms that perform desired functions. For hundreds of years, humans have engineered the development of food crops and domesticated animals through selective breeding practices. For example, the modern dairy cow is the result of centuries of carefully breeding individual animals that carried the genetic trait for high milk production. However, new technology makes it possible for scientists to restructure the DNA molecules themselves and thus obtain more rapid and more radical genetic changes than were possible in the past. This new process is commonly called recombinant DNA technology or gene splicing because it involves disassembling the DNA molecule and then recombining or splicing the pieces according to a new pattern. The gene-spliced DNA molecule may have a genetic code that has never existed before.
Although recombinant DNA technology is still in its infancy, it has al ready demonstrated its value. New crop breeds produced by this process are already growing in farmers’ fields. Crops that are genetically engineered to resist pests, diseases, and drought could be important in efforts to alleviate starvation around the world. Scientists are trying to use genetic engineering to produce important drugs such as insulin (胰岛素) and interferon (干扰素) cheaply. They are also working on a genetically engineered generation of wonder drugs to combat cancer and other killer diseases. However, the recombinant DNA technology brings with it problems our society has not previously faced. Gene splicing could produce new disease microorganisms, deadly to us or to the plants and animals upon which we depend. The possibility of altering human genetic structure raises serious moral, political, and social is sues. Genetic engineering illustrates dramatically the promises and dangers of technological development. The decisions our society makes about genetic engineering will undoubtedly have tremendous consequences in the years to come. [br] The author’s attitude towards genetic technologies is ______.
选项
A、enthusiastic
B、indifferent
C、critical
D、objective
答案
D
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3003749.html
相关试题推荐
GiantPandaCharacteristicsofGian
GiantPandaCharacteristicsofGian
GiantPandaCharacteristicsofGian
GiantPandaCharacteristicsofGian
GiantPandaCharacteristicsofGian
DoesGeneticResearchThreatenOurCivilLiberties?
DoesGeneticResearchThreatenOurCivilLiberties?
DoesGeneticResearchThreatenOurCivilLiberties?
DoesGeneticResearchThreatenOurCivilLiberties?
DoesGeneticResearchThreatenOurCivilLiberties?
随机试题
[originaltext]Oneday,apoorboywhowastryingtopayhiswaythroughsch
Normallyastudentmustattendacertainnumberofcoursesinordertogradu
全党要充分认识这场伟大斗争的长期性、复杂性、艰巨性,发扬斗争精神.提高斗争本领,
求助者向心理咨询师主倾诉,他很喜欢某女同学,为此,天天想,日夜思,十几年没有改变
在体育摄影中主要的对焦方法是()A.自动聚焦 B.手动调焦 C.区域聚焦
下列哪项精索静脉曲张的治疗是不正确的()A.精索内静脉与腹壁深静脉吻合
女性,24岁,心悸、面色苍白、巩膜轻度黄染,脾脏肋下2cm。血红蛋白80g/L,
下列关于基金管理人及其从业人员的说法,正确的是( )。A.基金从业人员不得买卖
端子箱内应加装驱潮加热装置,装置应设置为()状态,驱潮加热装置电源应单独设置
常用的不确定性分析的方法有( )。A.盈亏平衡分析 B.偿债能力分析 C.敏
最新回复
(
0
)