单选题苯丙酮尿症是一种隐性纯合的严重的代谢缺陷病症，基因位于常染色体上。如果两个正常的双亲，生了一个患病的女儿，一个正常表型的儿子，那么儿子是此病基因携带者的概率是______

单选题如果在第三代中雄性1与雌性4交配，它们的第一个子代是淡黄毛的概率是______

单选题染色体结构变异中的缺失和重复在染色体配对中都形成环(瘤)，但这两种变异形成的环所涉及的染色体是不同的，其中缺失环涉及______。 A．缺失染色体 B．部分重复染色体 C．正常染色体 D．缺失和正常染色体交换

单选题在一个链霉素抗性的Hfr菌株中，已知A位点比B位点先转移，而Strs位点最后转移，用菌株HfrA+B+Strs与F-A-B-StrR菌株接合，经一定时间用搅拌器中断接合，添加链霉素，然后分析活菌的基因型，各种基因型如下：A-B-=80% A+B+=10% A+B-=50% A-B+=5%，从这些资料看，A和B之间的重组率应是______ A.10% B.20% C.50% D.33.3% E.上述答案均不对

单选题一条雌鲫鱼一年内能繁殖约3000余条幼鱼，但能够生存下来并发育成熟的却很少，按照达尔文进化观点，这个实例说明了( )。

单选题在水稻三系配套中，S(rr)为不育系，以下质核互作类型中可作为恢复系的是

单选题生物进化的内在因素是( )。

单选题放毒型和敏感型草履虫在细胞交换后，其F2代中放毒型和敏感型的比例为1:1，其亲本系的基因型为______。 A．KK和KK B．Kk和Kk C．KK和kk D．kk和kk

单选题在一个隔离的岛上住着5800个人，其中2800人是男性。有196个男性患有红绿色盲。该色盲是由于伴X隐性突变因子(r)造成的。该色盲不影响个体的健康。在该岛上至少有一个女性患此种色盲的可能性是多少?

单选题下表是T4噬菌体5个表型相似的突变体的互补实验结果(+、-分别表示能和不能互补)，试根据结果判断他们分属于几个顺反子?______ 1 2 3 4 5 1 - + + + + 2 - + - + 3 - + - 4 - + 5 - A．2 B．3 C．4 D．5

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( )。