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
If you go down to the woods today, you may meet high-tech trees—genetically modified to speed their growth or improve the qualit
If you go down to the woods today, you may meet high-tech trees—genetically modified to speed their growth or improve the qualit
admin
2016-04-30
49
问题
If you go down to the woods today, you may meet high-tech trees—genetically modified to speed their growth or improve the quality of their wood. Genetically-engineered food crops have become increasingly common, albeit controversial, over the past ten years. But genetic engineering of trees has lagged behind.
Part of the reason is technical. Understanding, and then altering, the genes of a big pine tree are more complex than creating a better tomato. While tomatoes sprout happily, and rapidly, in the laboratory, growing a whole tree from a single, genetically altered cell in a test tube is a tricky process that takes years, not months. Moreover, little is known about tree genes. Some trees, such as pine trees, have a lot of DNA—roughly ten times as much as human. And, whereas the Human Genome Project is more than half-way through its task of isolating and sequencing the estimated 100, 000 genes in human cells, similar efforts to analyze tree genes are still just saplings(幼苗).
Given the large number of tree genes and the little that is known about them, tree engineers are starting with a search for genetic "markers". The first step is to isolate DNA from trees with desirable properties such as insect resistance. The next step is to find stretches of DNA that show the presence of a particular gene. Then, when you mate two trees with different desirable properties, it is simple to check which offspring contain them all by looking for the genetic markers. Henry Amerson, at North Carolina State University, is using genetic markers to breed fungal resistance into southern pines. Billions of these are grown across America for pulp and paper, and outbreaks of disease are expensive. But not all individual trees are susceptible. Dr. Amerson’s group has found markers that distinguish fungus-resistant stock from disease-prone trees. Using traditional breeding techniques, they are introducing the resistance genes into pines on test sites in America.
Using genetic markers speeds up old-fashioned breeding methods because you no longer have to wait for the tree to grow up to see if it has the desired traits. But it is more a sophisticated form of selective breeding. Now, however, interest in genetic tinkering(基因修补)is also gaining ground. To this end, Dr. Amerson and his colleagues are taking part in the Pine Gene Discovery Project, an initiative to identify and sequence the 50,000-odd genes in the pine tree’s genome Knowing which gene does what should make it easier to know what to alter.
What can we learn about the research on tree genes?
选项
A、The research methods are the same as the analysis of human genes.
B、The findings are expected to be as fruitful as the analysis of human genes.
C、It will take as much time and effort as the analysis of human genes.
D、The research has been mainly concentrated on the genes of young trees.
答案
A
解析
第2段末句中的similar efforts指的就是task of isolating and sequencing,即分析基因的常用方法,该句表明人类基因和树种基因的分析方法相同,但进展有差别,因此选项A为正确的推断。
转载请注明原文地址:https://kaotiyun.com/show/PtG7777K
0
大学英语六级
相关试题推荐
Biologically,thereisonlyonequalitywhichdistinguishesusfromanimals:theabilitytolaugh.Inauniversewhichappearst
YouDon’tHavetoBe18:GoingtoCollegeasanAdultA)Everysooften,especiallywhenI’mfeelingdown,Itakeoutmyoldcoll
YouDon’tHavetoBe18:GoingtoCollegeasanAdultA)Everysooften,especiallywhenI’mfeelingdown,Itakeoutmyoldcoll
Mostpeopledon’tenjoyfacingthedifficultsituationsthatsometimesoccurwithcoworkersintheworkplace.Suchsituationsma
FilmSchoolsA)Filmschoolsandfilmdirectingschoolsprovideaspiringfilmstudentswithasolidunderstandingofthemanyfac
A、Hegetsillatthesametimeeveryyear.B、Hedoesn’tgetenoughexercise.C、Heoftenhasdifficultyinsleeping.D、He’ssick
A、Animalsdon’tliketocrywhilehumanbeingsdo.B、Humanbeingscrybecauseoftheiremotionswhileanimalsdon’t.C、Human’st
A、Cooperationandconcession.B、Equalityandmutualbenefit.C、Exchangingdailynecessities.D、Introducingadvancedtechnology.
Settinganearlierbedtimeforyourchildrencouldhelpkeeptheirweight【B1】______,anewstudyfinds.Fastfood,toomuchscree
A、FuturegrowthofcollegestudentsinAmericaislikelytobequicker.B、Therearelessthan2,000universitiesorcollegesin
随机试题
在行政复议中,被申请人拒绝履行复议决定,复议机关可以()。
现场控制器(直接数字控制器DDC)是输出(),对电动调节阀进行模拟控制。
质量等级C、D属于优质碳素结构钢,主要用于对()要求较高的钢结构。
质量事故的处理过程包括事故调查及事故原因分析和()。
下列说法中,错误的一项是()。
张某早晨批发了1500元的苹果和葡萄,苹果每斤325元,葡萄每斤25元。到下午全部售完后发现,苹果平均每斤盈利10%,而葡萄损耗严重,平均每斤亏损15%。两种水果共获利100元。问张某早晨批发了多少斤苹果?()
语言是语言科学的实验材料。濒危语言蕴藏着罕见的语言特征,可供语言研究的内容深奥而丰富。由于我们对语言研究的历史还十分短暂,对语言的了解还十分肤浅,所以每一种语言的消失都会带走语言学信息,使我们失去一个理解语言本质的机会,失去一个研究的样本,这意味着我们将更
()对于《归田园居》相当于王维对于()
WhenaScottishresearchteamstartledtheworldbyrevealing3monthsagothatithadclonedanadultsheep,PresidentClinton
Itwasreportedthata73-year-oldmandiedonanEtihadflight______toGermanyfromAbuDhabi.
最新回复
(
0
)