单选题体内调节氧化磷酸化的基本因素是

单选题下列关于核糖体的叙述正确的是 A.tRNA的三级结构形式 B.参与转录终止，因为翻译紧接着转录之后 C.有转运氨基酸的作用 D.遗传密码的携带者 E.由rRNA和蛋白质构成

单选题A．氢键断裂B．肽键断裂C．疏水键断裂D．盐键断裂E．构象变化

单选题下列病毒中哪一个属于正链RNA病毒?

单选题结晶牛胰岛素的人工合成是生命科学上的重要成果，对生命起源问题的哪个阶段提供了有利证据?( )

单选题下列哪种碱基只见于DNA而不见于RNA

单选题关于V-src病毒癌基因叙述正确的是 A.存在于DNA病毒基因组中 B.来源于Rous肉瘤病毒 C.癌基因产物为受体型酪氨酸蛋白激酶 D.是第一个被证实的病毒癌基因 E.引起体外培养的细胞发生恶性转化

单选题原核生物基因转录终止子在终止点前均有( )。

单选题在转录过程中，三种真核RNA聚合酶都需要的转录因子是：

单选题转录延长中，RNA聚合酶的口亚基

单选题蛋白X是一种跨膜蛋白，如果通过分子生物学技术截去它的停止转移序列，那么突变的X在细胞中的最后定位是：

单选题关于启动子叙述错误的是______ A.原核和真核生物均有 B.调控转录起始 C.与RNA聚合酶结合 D.都不能被转录 E.位于转录起始点附近

单选题遗传密码简并性的特点是 A.防止错位突变翻译出不同的氨基酸 B.引起错位突变 C.密码子与反密码子结合 D.氨基酰-tRNA进入线粒体 E.翻译相同的氨基酸

单选题More than any other industry, the luxury-goods business needs people to feel good about spending money. So at a recent conference in Moscow, Bernard Arnault, the head of Moet Hennessy Louis Vuitton (LVMH), the world's biggest luxury-goods group, went to great lengths to dismiss investors' fears about the impact on the industry of America's credit crisis, a possible recession and the weak dollar. Indeed, Mr. Arnault said he expects the industry's sales almost to double in the next five years, thanks to strong demand from emerging markets and the creation of new wealth across the globe. After a depressing period at the beginning of the decade when the terrorist attacks in America, the outbreak of SARS and the war in Iraq reduced international travel and people's appetite for frivolous things, the industry has had three excellent years. According to Bain, a consultancy, sales of luxury goods grew by 9% in 2006 to 159 billion ($ 200 billion) and will reach about 170 billion this year, which would double the 1996 figure. Europe remains the biggest market, with about 40% of sales, though the strongest growth is in China, Russia, the Middle East and some Latin American countries. Can the industry really double again in half the time? Analysts at Citigroup say that Christmas will be good this year for luxury-goods firms, but they are more cautious about next year because of worries about falling demand in America. It is tempting to think that luxury goods are isolated from the broader economy, because customers are rich enough to ignore it, says Luca Solca, a luxury-goods analyst. But the industry's expansion into a broader "aspirational" market, by selling to the merely affluent, makes it susceptible. And as luxury firms expand in Asia and the Americas, they will continue to suffer currency woes. Most of the industry's production is in the euro-zone, mainly in France and Italy. Even the optimistic Mr. Arnault complained at his firm's recent annual meeting that the euro had reached "incomprehensible" levels against the dollar and the yen. Luxury companies could shift more of their production to countries with weaker currencies and cheap labor (ie, China), but some customers-especially Asian customers-want the elitism and craftsmanship associated with products manufactured in Europe. At least sales in emerging markets are growing fast. But Melanie Flouquet, a luxury analyst at JPMorgan, an investment bank, says that this growth is not enough to offset a slowdown in America. Chinese and Russian consumers account for around 7% and 4% of global luxury sales respectively, compared with 16-18% for Americans. Even so, European firms are sticking to their plans in New York, America's fashion capital. Gucci will open its biggest shop in February in Trump Tower, a shiny skyscraper on New York's Fifth Avenue. Ermenegildo Zegna will also open a shop on Fifth Avenue next year. And this week Dolce Gabbana re-opened its spruced-up shop on Madison Avenue. Claudia D' Arpizio of Bain thinks luxury makers need to follow Giorgio Armani and segment their customers more carefully with different product lines at different price ranges. She predicts that the industry will see solid growth rates of up to 10% a year in the near term. This means that the industry could double in ten years-by which time China is likely to account for more than a quarter and maybe as much as a third of the world's consumption of luxury goods. Yet Mr. Arnault's rosy prediction seems unlikely to come true. As Americans tighten their purse-strings, over-optimism is a luxury even this industry cannot afford.

单选题人类基因组完全图谱的公布是在( )年2月12日。

单选题下面关于真核生物翻译的叙述中，哪一个是正确的?( )

单选题制作可摘局部义齿印模，选择的托盘与牙弓内外侧应有多大间隙

单选题以下关于顺式作用元件的叙述哪项是错误的( )。

单选题关于核苷酸的叙述不正确的是______。

单选题下列克隆载体对外源DNA容载量最大的是( )。