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转基因食品是否安全
添加时间:2014-06-30 15:52:40 浏览次数: 作者:未知
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  • Traditional plant breeding involve s crossing varieties of the same species in ways they could cross naturally.For example,disease-resistant varieties of wheat have been crossed with high-yield wheat to combine these properties.This type of natural gene1 exchange is safe and fairly predictable.

    Genetic2 engineering(GE)involves exchanging genes3 between unrelated species that cannot naturally exchange genes with each other.GE can involve the exchange of genes between vastly different species――e.g.putting scorpion4 toxin5 genes into maize6 or fish antifreeze genes into tomatoes.It is possible that a scorpion toxin gene,even when it is in maize DNA,will still get the organism to produce scorpion toxin――but what other effects may it have in this alien environment?We are already seeing this problem――adding human growth hormone8 genes to pigs certainly makes them grow――but it also gives them arthritis9 and makes them cross-eyed,which was entirely10 unpredictable.

    It will be obvious,for example,that the gene for human intelligence will not have the same effect if inserted into cabbage DNA7 as it had in human DNA――but what side-effect would it have?In other words,is GM food safe to eat?The answer is that nobody knows because long-term tests have not been carried out.

    Companies wanting a GM product approved in the UK or USA are required to provide regulatory bodies with results of their own safety tests.Monsanto’s soya beans were apparently11 fed to fish for10weeks before being approved.There was no requirement for independent testing,for long-term testing,for testing on humans or testing for specific dangers to children or allergic12 people.

    The current position of the UK Government is that“ There is no evidence of long-term dangers from GM foods.”In the US,the American Food and Drug Administration is currently being prosecuted13 for covering up research that suggested possible risks from GM foods.

    传统的植物培育方法,是依照植物自然杂交的方式,进行相同物种的人工杂交。比如,抗病小麦同高产小麦杂交,形成了一种具有双重特性的新的小麦品种。这种自然的基因交换既安全,又具有相当的可预见性。

    基因工程是在彼此毫无关系的物种之间,相互交换在自然条件下无法交换的基因。它可在有巨大差异的物种之间进行基因交换。比如,将蝎子毒素基因注入玉米,或者将鱼防冻基因注入西红柿。即使在玉米DNA中,蝎子毒素基因依然可能获得有机组织产生蝎子毒素。但是在这种异质的环境中,这种基因产品会有什么其他作用吗?我们实际上已经发现这个问题:将人类生长荷尔蒙基因植入猪的体内,一定会使猪的生长加速,但是同时也使猪患上了关节炎和内斜视,而这一切是完全无法预测的。

    打个比方,人类的智力基因显而易见在人体DNA内和注入卷心菜DNA后的作用是不同的。但将它植入卷心菜中会产生什么样的副作用呢?换句话说,食用转基因食品安全吗?没有人知道答案,因为人们尚未进行长期的测试。

    在英国或者美国,一个公司如果希望其转基因产品获得批准,它必须向管理机构提供本公司转基因产品安全测试的结果。Monsanto的大豆在获得批准之前,曾用了10周时间进行喂鱼试验。目前,尚无要求对转基因产品进行独立测试、长期测试、人体测试,或者就其对儿童及过敏者所造成的特定危险进行测试。

    英国政府目前的态度是:“尚无证据表明食用转基因食品存在长期性的危险。”在美国,人们正在起诉美国食品药品管理局掩盖转基因食品安全性的研究结果,这些研究结果表明,食用转基因食品可能导致危险。

     12级    英文科普 


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    1 gene [dʒi:n] WgKxx   第7级
    n.遗传因子,基因
    参考例句:
    • A single gene may have many effects. 单一基因可能具有很多种效应。
    • The targeting of gene therapy has been paid close attention. 基因治疗的靶向性得到了密切关注。
    2 genetic [dʒəˈnetɪk] PgIxp   第7级
    adj.遗传的,遗传学的
    参考例句:
    • It's very difficult to treat genetic diseases. 遗传性疾病治疗起来很困难。
    • Each daughter cell can receive a full complement of the genetic information. 每个子细胞可以收到遗传信息的一个完全补偿物。
    3 genes [dʒi:nz] 01914f8eac35d7e14afa065217edd8c0   第7级
    n.基因( gene的名词复数 )
    参考例句:
    • You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因,所以能够活得很长。 来自《简明英汉词典》
    • Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪
    4 scorpion [ˈskɔ:piən] pD7zk   第10级
    n.蝎子,心黑的人,蝎子鞭
    参考例句:
    • The scorpion has a sting that can be deadly. 蝎子有可以致命的螫针。
    • The scorpion has a sting that can be deadly. 蝎子有可以致命的螫针。
    5 toxin [ˈtɒksɪn] hn5wb   第11级
    n.毒素,毒质
    参考例句:
    • Experts have linked this condition to a build-up of toxins in the body. 专家已把这一病症与体内毒素的积累联系起来。
    • Tests showed increased levels of toxin in shellfish. 检验表明水生有壳动物的毒素水平提高了。
    6 maize [meɪz] q2Wyb   第9级
    n.玉米
    参考例句:
    • There's a field planted with maize behind the house. 房子后面有一块玉米地。
    • We can grow sorghum or maize on this plot. 这块地可以种高粱或玉米。
    7 DNA [ˌdi: en ˈeɪ] 4u3z1l   第8级
    (缩)deoxyribonucleic acid 脱氧核糖核酸
    参考例句:
    • DNA is stored in the nucleus of a cell. 脱氧核糖核酸储存于细胞的细胞核里。
    • Gene mutations are alterations in the DNA code. 基因突变是指DNA密码的改变。
    8 hormone [ˈhɔ:məʊn] uyky3   第8级
    n.荷尔蒙,激素,内分泌
    参考例句:
    • Hormone implants are used as growth boosters. 激素植入物被用作生长辅助剂。
    • This hormone interacts closely with other hormones in the body. 这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
    9 arthritis [ɑ:ˈθraɪtɪs] XeyyE   第9级
    n.关节炎
    参考例句:
    • Rheumatoid arthritis has also been linked with the virus. 风湿性关节炎也与这种病毒有关。
    • He spent three months in the hospital with acute rheumatic arthritis. 他患急性风湿性关节炎,在医院住了三个月。
    10 entirely [ɪnˈtaɪəli] entirely   第9级
    ad.全部地,完整地;完全地,彻底地
    参考例句:
    • The fire was entirely caused by their neglect of duty. 那场火灾完全是由于他们失职而引起的。
    • His life was entirely given up to the educational work. 他的一生统统献给了教育工作。
    11 apparently [əˈpærəntli] tMmyQ   第7级
    adv.显然地;表面上,似乎
    参考例句:
    • An apparently blind alley leads suddenly into an open space. 山穷水尽,豁然开朗。
    • He was apparently much surprised at the news. 他对那个消息显然感到十分惊异。
    12 allergic [əˈlɜ:dʒɪk] 4xozJ   第8级
    adj.过敏的,变态的
    参考例句:
    • Alice is allergic to the fur of cats. 艾丽斯对猫的皮毛过敏。
    • Many people are allergic to airborne pollutants such as pollen. 许多人对空气传播的污染物过敏,比如花粉。
    13 prosecuted ['prɔsikju:tid] Wk5zqY   第7级
    a.被起诉的
    参考例句:
    • The editors are being prosecuted for obscenity. 编辑因刊载污秽文字而被起诉。
    • The company was prosecuted for breaching the Health and Safety Act. 这家公司被控违反《卫生安全条例》。

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