首页
登录
职称英语
If you go down to the woods today, you may meet high-tech trees—genetically
If you go down to the woods today, you may meet high-tech trees—genetically
游客
2023-08-14
29
管理
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. [br] What does the author think about the genetic engineering of pine trees?
选项
A、Time-consuming.
B、Worthwhile.
C、Significant.
D、Technically impossible.
答案
A
解析
第2段第3句中的that takes years表明研究树木的基因改造技术将花费很长时间。因此选项A为本题答案。原文没有就选项B和C两方面做出讨论,因此不能推断出这两个选项;虽然第2段首句提到technical一词,但文章表明树木基因改造技术是可行的,只是会花费较多的时间,因此选项D也不正确。
转载请注明原文地址:https://tihaiku.com/zcyy/2924141.html
相关试题推荐
Ifyougodowntothewoodstoday,youmaymeethigh-techtrees—genetically
Ifyougodowntothewoodstoday,youmaymeethigh-techtrees—genetically
Ifyougodowntothewoodstoday,youmaymeethigh-techtrees—genetically
转基因食品(GeneticallyModifiedFood;GMF)是利用基因工程技术生产的食品。它具有产量高、营养丰富、抗病力强等优势,但也存在明
转基因食品(GeneticallyModifiedFood;GMF)是利用基因工程技术生产的食品。它具有产量高、营养丰富、抗病力强等优势,但也存在明
Ifyougodowntothewoodstoday,youmaymeethigh-techtrees—genetically
Ifyougodowntothewoodstoday,youmaymeethigh-techtrees—genetically
Ifyougodowntothewoodstoday,youmaymeethigh-techtrees—genetically
Ifyougodowntothewoodstoday,youmaymeethigh-techtrees—genetically
Ifyougodowntothewoodstoday,youmaymeethigh-techtrees—genetically
随机试题
Peopleinsunny,outdoorsystates—Louisiana,Hawaii,Florida—saytheyareth
Ifyoudidn’tknowanybetter,youmightthinkthatStar,Snuppy,CCandAND
Speaktohimslowly______hemayunderstandyoubetter.A、sinceB、sothatC、forD、
[originaltext]Thecostisgoingupforjustabouteverything,andcolleget
社会意识相对独立性的最突出表现是( )。A.社会意识的历史继承性 B.各种社
关于阻塞性肺气肿的体征,下列正确的是()A.桶状胸 B.触觉语颤减弱 C
我国四大名亭是因古代文人雅士的诗歌文章而闻名的景点。它们分别是: A湖心亭、醉
既可用作上行文,又可用作下行文,也可用作平行文的党政机关公文文种是:A.通知
2007年3月,中国银监会和国家外汇管理局发布《合格境内机构投资者境外证券投资(
假设年利率为5%,张先生准备拿出10000元进行投资,若按复利计算,3年后张先生
最新回复
(
0
)