单选题假设某种二倍体植物A的细胞质在遗传上不同于植物B，为了研究核一质关系，想获得一种植株，这种植株具有A的细胞质，而细胞核主要是B的基因组，应该怎么做?

单选题对一个生物个体细胞有丝分裂进行细胞学检查，发现后期出现染色体桥，表明该生物个体可能含有______染色体。 A．臂间倒位 B．相互易位 C．臂内倒位 D．顶端缺失

单选题细菌杂交实验中，F因子和部分细菌染色体转移频率都比较高的杂交组合是( )。

单选题据测家兔体重大小是由具有相等和加性效应的一些基因决定的。在从大、小梁3品种杂交所得到的2012只F2中有8只和小亲本品种一样，还有8只和大亲本品种一样大，试问，有多少对基因在起作用?( )

单选题The history of responses to the work of the artist Sandro Botticelli (1444 ～ 1510) suggests that widespread appreciation by critics is a relatively recent phenomenon. Writing in 1550, Vasari expressed an unease with Botticelli's work, admitting that the artist fitted awkwardly into his evolutionary scheme of the history of art. Over the next two centuries, academic art historians defamed Botticelli in favor of his fellows Florentine, Michelangelo. Even when anti-academic art historians of the early nineteenth century rejected many of the standards of evaluation adopted by their predecessors, Botticelli's work remained outside of accepted taste, pleasing neither amateur observers nor connoisseurs. (Many of his best paintings, however, remained hidden away in obscure churches and private homes. ) The primary reason for Botticelli's unpopularity is not difficult to understand: most observers, up until the midnineteenth century, did not consider him to be noteworthy, because his work, for the most part, did not seem to these observers to exhibit the traditional characteristics of fifteenth-century Florentine art. For example, Botticelli rarely employed the technique of strict perspective and, unlike Michelangelo, never used chiaroscuro. Another reason for Botticelli's unpopularity may have been that his attitude toward the style of classical art was very different from that of his contemporaries. Although he was thoroughly exposed to classical art, he showed little interest in borrowing from the classical style. Indeed, it is paradoxical that a painter of large-scale classical subjects adopted a style that was only slightly similar to that of classical art. In any case, when viewers began to examine more closely the relationship of Botticelli's work to the tradition of fifteenth-century Florentine art, his 'reputation began to grow. Analyses and assessments of Botticelli made between 1850 and 1870 by the artists of the Pre Raphaelite movement, as well as by the writer Pater (although he, unfortunately, based his assessment on an incorrect analysis of Botticelli's personality), inspired a new appreciation of Botticelli throughout the English-speaking world. Yet Botticelli's work, especially the Sistine frescoes, did not generate worldwide attention until it was finally subjected to a comprehensive and scrupulous analysis by Home in 1908. Home rightly demonstrated that the frescoes shared important features with paintings by other fifteenth-century Florentines features such as skillful representation of anatomical proportions, and of the human figure in motion. However, Home argued that Botticelli did not treat these qualities as ends in themselves--rather, that he emphasized clear depletion of a story, a unique achievement and one that made the traditional Florentine qualities less central. Because of Home's emphasis crucial to any study of art, the twentieth century has come to appreciate Bottieelli's achievements.

单选题利用以下信息解答问题(1)～(3)：两种纯系玉米穗轴的平均长度分别为0.27m和0.09m。在该性状中包含的多基因都表现出加性基因作用。

单选题谁是第一个在进化领域中提出了一个有条理的理论?( )

单选题香蕉是一个同源三倍体，3n=33。在减数分裂时就可能出现______等不同的联会方式，造成后期工不均衡分离，形成的配子基本上都是不育的。 A．三价体和四价体 B．三价体、二价体和单价体 C．二价体和单价体 D．三价体和单价体

单选题囊性纤维变性是一种常染色体遗传病。在欧洲的人群中，每2500个人中就有一人患此病。如一对健康的夫妇有一个患有此病的孩子；此后，该妇女又与一健康的男子再婚。再婚的双亲生一孩子患该病的机会是多少?( )

单选题在细菌转录中，使RNA聚合酶与DNA启动子牢固结合的关键因子是 a．α2； b．ββ′； c．α2ββ′； d．σ(sigma)。

单选题外耳道多毛症是一种遗传病，父亲是患者，则儿子全是患者，女儿全正常。此遗传病基因是( )。

单选题When an invention is made, the inventor has three possible (1) of action open to him: he can give the invention to the world by publishing it, keep the idea (2) , or patent it. A (3) patent is the result of a bargain (4) between an inventor and the state, hut the inventor gets a limited period of monopoly and publishes full details of his invention to the public after that period (5) . Only in the most exceptional circumstances (6) the lifespan of a patent (7) to alter this normal process of events. The longest extension ever (8) was to Georges Valensi; his 1939 patent for color TV receiver circuit was extended until 1971 because for most of the patent's normal life there was no color TV to (9) and thus no hope for reward for the invention. Because a patent remains permanently (10) after it has terminated, the shelves of the library attached to the (11) office contain details of literally millions of ideas that are free for anyone to use and, if (12) than half a century, sometimes even repatent. Indeed, patent experts often advise anyone (13) to avoid the high cost of conducting a search through (14) patents that the one sure way of violation of any other inventor's right is to plagiarize a dead patent. Likewise, because publication of an idea in any other form (15) invalidates further patents on that idea, it is traditionally (16) to take ideas from other areas of print. Much modern technological advance is (17) on these presumptions of legal security. Anyone closely (8) in patents and inventions soon learns that most "new" ideas are, in fact, as old as the hills. It is theft reduction to commercial practice, either through necessity or dedication, or through the availability of new technology, (19) makes news and money. The basic patent for the theory for magnetic recording dates back to 1886. Many of the original ideas behind television originate (20) the late 19th and early 20th century. Even the Volkswagen rear engine ear was anticipated by a 1904 patent for a cart with the horse at the rear.

单选题某植物体细胞内只有一套染色体，所以他是______。 A.单价体 B.单体 C.缺体 D.一倍体

单选题两对基因杂合体F 1 (AaBb)自交后代重组型等于亲组型的遗传是( )。

单选题利用一种Hfr菌株和其对应的F-菌株进行中断杂交试验，结果如图所示，图中列出了a、b、c、d、e、f6个位点的转移数，纵轴表示位点的重组率，横轴表示接合的时间，从这些资料看，Hfr菌株的连锁图是______

单选题当细菌核糖体亚基在CsCl介质中进行离心时，30S和50S亚基分别变为23S和42S亚基，这是由于除去了某些成分所致，被除去的成分是 a．16S rRNA； b．23S rRNA； c．16S rRNA+23S rRNA； d．蛋白质。

单选题在一个有性生殖的自然种群中，除了具有种群大、没有突变发生、没有新基因加入以及个体间的交配是随机的以外，还需具备下列哪一条件，种群的基因库是稳定的( )。

单选题在真核细胞中tRNA的转录是为 a．RNA pol Ⅰ工负责的； b．RNA pol Ⅱ负责的； c．RNA pol Ⅲ负责的； d．不由任何RNA pol负责。

单选题两个植物自交系，它们的种子重量分别为0.2kg和0.4kg，杂交得到的F1种子为0.3kg，F1×F1杂交产生了1024个植株，4株为0.2kg重的种子，4株为0.4kg重的种子，其他植株的种子重量则介于二者中间，由此可估计决定种子重量的基因约为( )对。