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
One of industrial agriculture’s biggest GMO crops may have just backfired (产生事与愿违的后果). Scientists have confirmed that corn-destr
One of industrial agriculture’s biggest GMO crops may have just backfired (产生事与愿违的后果). Scientists have confirmed that corn-destr
admin
2015-03-28
33
问题
One of industrial agriculture’s biggest GMO crops may have just backfired (产生事与愿违的后果). Scientists have confirmed that corn-destroying rootworms have evolved to be resistant to the Bt corn engineered to kill them.
Bt stands for Bacillus thuringiensis (苏云金芽孢杆菌), the name of the genetically modified corn’s "donor" organism. Bacillus thuringiensis is a naturally occurring soil bacterium that produces protein crystals that bind to certain receptors in the rootworm’s intestine (肠), killing it. For years, farmers have planted Bt corn as an alternative to spraying insecticides. Bt corn accounted for three-quarters of all corn planting in 2013. That may have to change.
After finding a cornfield in Iowa in 2011 that was decimated (大幅度下降) by rootworm despite being planted with the Bt corn, Iowa State University entomologist Aaron Gassmann and his team began to study the pests’ interactions with the genetically modified organism (or GMO) corn in a lab. Their study, published Monday in the Proceedings of the National Academy of Sciences, describes the western corn rootworm’s rapid evolution after feeding on the engineered crop.
But Bt corn is still capable of warding off other pests, so farmers will likely keep planting it. Except now they’ll need to use pesticides to protect their crop from rootworms. As entomologists warned the Environmental Protection Agency in 2012, rootworm resistance means that the environmental advantage of Bt corn — that it could be raised pesticide-free — may disappear.
"Unless management practices change, it’s only going to get worse," Gassmann told Wired. "There needs to be a fundamental change in how the technology is used."
Scientists have predicted for years that this could happen, but warnings were repeatedly ignored by regulators and farmers. It takes millions of dollars to develop seeds like Bt, so engineering an alternative is not an attractive option. Instead, the authors of another study on rootworm Bt resistance, which focuses on Nebraska, take a biodiversity approach.
"Crop rotation is the best tool," University of Nebraska-Lincoln entomologist Lance Meinke told Farm & Ranch Guide. "Generally, one year of soybeans in a field with resistant western corn rootworms wipes out that population. The beetles will lay eggs that hatch, but when larvae (幼虫) try to feed on soybean plants, they don’t find the nutrients they need and they die."
Crop rotation can suppress rootworm populations over time, reducing the threat posed by their new Bt resistance.
But as entomologist Elson Shields of Cornell University told Wired, rootworm is just one symptom of a system wide problem that will likely come back to bite the GMO seed industry’s focus on short-term profit. The next engineered seed trait "will fall under the same pressure," said Shields, "and the insect will win."
Lance Meinke thinks the best approach to the problem of rootworm Bt resistance is______.
选项
A、planting soybeans
B、raising beetles
C、adding fertilizer
D、rotating crops
答案
D
解析
第3段首句提到,内布拉斯加林肯大学的昆虫学家兰斯.梅恩克告诉《农场&牧场指南》,轮作是最好的方法。即兰斯.梅恩克认为轮作是解决可抵抗Bt的根虫的最佳方法,故D)符合文意。文中说的是大豆与玉米的轮作,因此不能只种植大豆,故A)不合文意。由本段末句可知,种植大豆是为了杀灭甲虫,因此B)也符合题意。文中没有提及土地施肥的问题,故C)属于无中生有,予以排除。
转载请注明原文地址:https://kaotiyun.com/show/pch7777K
0
大学英语六级
相关试题推荐
Somepeoplebelievethatyouhavetobeaspecialkindofpersontosellaproduct.Butalthoughitisclearthatasuccessfuls
A、Gettingrichquickly.B、Distinguishingoneself.C、Respectingindividualrights.D、Doingcredittoone’scommunity.B推理题在美国,当人们
A、Promiselong-termcooperationwiththeCompany.B、Explainfranklytheirowncurrentfinancialsituation.C、Payfortheprintin
CampusCrimeWeoftenthinkofagricultureasplantingseedsandharvestingcrops.Butmanycropsdonotcomefromseeds.Ma
A、Tokeepfit.B、Tostudywell.C、Toearnmoremoney.D、Togainesteem.A事实细节题。短文开头提到,新年伊始是制订塑身计划的好时候,努力做一个身材匀称、健康快乐的人。
I’minterestedinthecriminaljusticesystemofourcountry.Itseemstomethatsomethinghastobedone,ifwe’reto【B1】____
A、Asupporteroffreeglobaltrade.B、AmemberoftheFoodCommission.C、AsupporterofFirstWorldfoodmarkets.D、Amemberof
MarriageisconsideredanoccasionofgreatrejoicingintheWestasitisinChina.ButintheWestthebrideissupposedtobe
Alcoholhasapeculiarrelationshiptohappiness.Wedrinktocelebrate,butbecausealcoholworksasadepressant,itendsupd
随机试题
其辨证为若本证五心烦热,午后潮热不明显,以心烦不眠为主者宜用何方
确诊I级高血压是( )确诊Ⅱ级高血压是( )
我国公路建设的资金来源有()。
背景:某市中心办公写字楼工程,总建筑面积25000m2,分为A、B两栋。A栋地上13层,地下2层,建筑高度54m,框架一剪力墙结构,结构施工垂直运输机械为塔式起重机,装饰装修垂直运输机械为人货两用的外用电梯。B栋地上4层,檐高20m,结构施工垂直
下列属于买断式回购交易的违约金额的有()
主管税务机关在对个人股权转让收入进行核定时首选的方法是()。
田径比赛规则规定,对第一次起跑犯规的运动员应给予警告,之后的每次起跑犯规的运动员均应取消该项目的比赛资格。()
五台山佛光寺现存东大殿,是()重要的建筑实物。
依次填入下列各句横线处的词语,最恰当的一组是()①颁奖会结束,与会者______着今年诺贝尔奖获得者库切走出会场。②总经理那样做,______是提高工作效率,但由于种种原因,其效果不尽如人意。③我们要重视资料的作用,留心资料
A、No,youcan’t.B、Ofcourse.C、Thanks.B听力原文:MayIborrowyourbike?意为:我可以借你的自行车吗?对于别人的请求应让表示同意或不同意,其中只有B表示同意,但是拒绝别人的请求时,表达应该比
最新回复
(
0
)