单选题细胞质基因的分离和重组的过程______。 A.类似于有丝分裂 B.类似于减数分裂 C.类似于细菌的二分分裂方式 D.没有规律，具有随机性

单选题如果一个平衡的群体中有4%个体表现出由单基因控制的隐性性状，那么两个没有表现出这个性状的个体的后代出现该隐性性状的比例为( )。

单选题It's obvious that humans are fundamentally different from other animal species. It's not so easy, though, to identify the traits that make human beings so special. Scientists realized long ago that other animals make tools, play jokes and even have a sense of justice and altruism—all things we once thought were unique to our species. Now a paper in the journal Current Biology has added another behavior to the list of what other animals share with us—and this one isn't quite so charming. After years of field observations in Uganda's Kibale National Park, John Mitani of the University of Michigan and several colleagues have concluded that chimps wage war to conquer new territory. "We already knew that chimps kill each other," says Mitani. "We've known this for a long time." What scientists didn't know for certain, at least in cases in which groups of chimps banded together to kill others, was why. One hypothesis, advanced more than a decade ago by anthropologist Richard Wrangham, was the idea of territorial conquest; circumstantial evidence from both Gombe and Mahale national parks in Tanzania bolstered the theory. In Mahale, for example, male members of one group mysteriously vanished, and another group then expanded into what had been their land. In Gombe, an existing group dissolved into civil war, resulting in killings and land takeovers. What's especially chilling about the observation is that the murder rate appears to be so high. The anthropologists couldn't be certain of how big a band the victims belonged to because they weren't used to a human presence and thus couldn't be accurately counted. But even a conservative estimate suggests that the death rate is significantly higher than you would see in war between human hunter-gatherer groups. Mitani isn't oblivious to the lesson some people might draw from the study. "Invariably, some will take this as evidence that the roots of aggression run very deep," he says, and therefore conclude that war is our evolutionary destiny. "Even if that were true," says Mitani, "we operate by a moral code that chimps don't have." Apart from that, he points out, the Pan troglodytes chimps he studies are one of two subspecies. The other is called Pan paniscus, also known as bonobos, and, says Mitani, "the latter, as far as we know, aren't nearly as aggressive with respect to intergroup relations. Yet they're equally close to us." That means that if we're wired for warfare, we're wired for peace too. Ultimately, the route we choose is still up to us.

单选题Griffith发现，在活的无毒菌液中加入死的有毒性细菌然后感染家鼠，结果家鼠很快死亡，并释放出大量的有毒性细菌，那么细菌经历了何种过程才有此现象?______ A.转导 B.易位 C.转化 D.接合 E.衰退

单选题小鼠中，黑毛由常染色体隐性基因决定。两个正常毛色的小鼠交配，产生了一个黑色雄鼠，该黑色雄鼠与一个正常毛色雌鼠再进行兄妹间交配，那么所产生的第一个小鼠是黑毛的概率是(假设没发生突变)______

单选题假如一个性状呈数量遗传，但估算的遗传力为0，那么下面这些结论中哪一个是正确的?( )

单选题在豚鼠中，黑毛对白毛是显性，如果基因库中90%是显性基因B，10%是隐性基因b，则种群中基因型BB、Bb、bb的频率分别是( )。

单选题达尔文认为，生物进化是( )。

单选题单倍体链孢霉一般是粉红色的，白色是它的突变型，如果把粉红色链孢霉与白色链孢霉进行杂交，其子代是粉红色的概率是______

单选题Who won the World Cup 1994 football game? What happened at the United Nations? How did the critics like the new play? (1) an event takes place, newspapers are on the streets (2) the details. Wherever anything happens in the world, reporters are on the spot to (3) the news. Newspapers have one basic (4) , to get the news as quickly as possible from its source, from those who make it to those who want to (5) it. Radio, telegraph, television, and (6) inventions brought competition for newspaper. So did the development of magazines and other means of communication. (7) , this competition merely spurred the newspapers on. They quickly made use of the newer and faster means of communication to improve the (8) and thus the efficiency of their own operations. Today more newspapers are (9) and read than ever before. Competition also led newspapers to branch out into many other fields. Besides keeping readers (10) of the latest news, today's newspapers (11) and influence readers about politics and other important and serious matters. Newspapers influence readers' economic choices (12) advertising. Most newspapers depend on advertising for very (13) . Newspapers are sold at a price that (14) even a small fraction of the cost of production. The main (15) of income for most newspapers is commercial advertising. The (16) in selling advertising depends on a newspaper's value to advertisers. This (17) in terms of circulation. How many people read the newspaper? Circulation depends (18) on the work of the circulation department and on the services or entertainment (19) in a newspaper's pages. But for the most part, circulation depends on a newspaper's value to readers as a source of information (20) the community, city, county, state, nation, and world—and even outer space.

单选题变异是生命的基本特征之一，细菌产生可遗传的变异来源于( )。

单选题关于自然选择，以下叙述错误的是( )。

单选题有一个杂交组合aaBB×AAbb，下列有关其F1的陈述正确的是______。 A.若位点间不连锁，产生Ab配子时，同样可产生AB配子 B.若位点间紧密连锁，与不连锁相比，F1的表型分布不同 C.若位点间紧密连锁，与不连锁相比，F2的表型分布不同 D.上述答案都不对

单选题杂合体中，呈现两个基因(一对基因)效应的现象称为______

单选题菌株A可以石油燃料为营养，菌株B则不能利用石油燃料，活化菌株B，杀死菌株A，混合在一起，几小时后，混合物变得混浊，经检查得知，混浊是菌株A快速生长的结果，引起的这种现象原因是______ A．性导 B．转录 C．转导 D．转化

单选题DNA聚合酶Ⅲ的描述中哪项不正确?( )

单选题关于数量性状的描述，正确的有______。 A.由多个基因控制 B.一般不受环境影响 C.呈现不连续变异 D.差别非常明显，“非此即彼”

单选题影响基因频率的因素是( )。

单选题转录的启始反应方程为(箭头只表示顺序)，其中R=RNApol，P=promoter，RPc=closedbinarycomplex，RPo=opencomplex，RPi·RNA=ternarycomplex。在这些步骤中a．1是可逆反应；b．2是可逆反应；c．3是可逆反应；d．1，2，3均不是可逆反应。

单选题荷兰科学家底·弗里斯(Hugo de Vries)把另外两位科学家的理论(或学说)联系到了一起，这两位科学家是( )。