填空题噬菌体是指寄生于______细胞中的病毒。

填空题位于同一基因位点上的各个等位基因，称为______基因。

填空题转化的频率随着DNA纯度的提高而______，转化可以在体外进行。

填空题宿主染色体在反转录病毒整合位点上会发生______。

填空题Almost every day we see something in the papers about the latest exciting developments in the space race. Photographs are regularly flashed to the earth from thousands and even millions of miles away. They are printed in our newspapers and shown on our television screens as a visible proof of the man's newest achievements. The photographs neatly sum up the results of these massive efforts to ' conquer space' and at the same time they exposed the absurdity of the undertaking. All we can see is an indistinguishable blob that is supposed to represent a planet seen from several thousand miles away. We are going to end up with a little moon-dust and a few stones which will be put behind glass in some museum. (41)__________ (42)__________It is just an extension of the race for power on earth. Only the wealthiest nations can compete and they do so in the name of pure scientific research. But in reality, all they are interested in is power and prestige. They want to impress us, their spectators, with a magnificent show of strength. Man has played the power game ever since he appeared on earth. Now he is playing it as it has never been played before. The space race is just another aspect of the age-old argument that "might is right". (43)__________But what has the space race done to relieve the suffering of the earth's starving millions? In what way has it raised the standard of living of any one of us? As far as the layman is concerned, the practical results of all this expenditure of money and efforts are negligible. Thanks to space research, we can now see television pictures transmitted live halfway across the globe and the housewife can use non-stick frying pans in the kitchen. The whole thing becomes utterly absurd when you think that no matter what problems man overcomes, it is unlikely that he will ever be able to travel even to the nearest star. (44)__________For the first time in his history, man has the overwhelming technological resources to combat human suffering, yet he squanders them on meaningless pursuits. (45)__________Individuals with limited budgets usually get their priorities right; they provide themselves with necessities before trying to obtain luxuries. Why can't great nations act in the same sensible way? Let us put our house in order first and let space look after itself. [A] An increasing number of people even begin to picture a space travel in recent years. [B] Poverty, hunger, disease and war are man's greatest enemies and the world would be an infinitely better place if the powerful nations devoted half as much money and effort to these problems as they do to the space race. [C] The space race is not simply the objective search for knowledge though it is often made out to be. [D] On the other hand, people benefit dramatically from the development of science and technology. [E] This is hardly value for money when you think that our own earth can provide countless sights that are infinitely more exciting and spectacular. [F] We are often told that technological know-how, acquired in attempting to get us into orbit, will be utilized to make better on earth. [G] If a man deprived himself and his family of food in order to buy and run a car, we would consider him mad.

填空题烟草的自交不亲和性是由S 1 ，S 2 ，…，S 15 等一系列复等位基因控制的。若用S 2 S 4 作父本给S 1 S 4 授粉，预期新种子中胚乳的基因型为______或______，胚的基因型为______或______。

填空题细胞分化意味着优先合成某些特异性蛋白质，所以决定细胞分化的主要因素是______。

填空题生物体的性别决定方式有多种类型，试确定下列个体的性别：人类XXY______，XO______；果蝇AAXXY______，AAXY______，AAAXX______；鸡ZW______。

填空题利用人工的方法在体外合成核酸包括两种方法：一种是______；另一种是______。

填空题黑腹果蝇的截毛基因位于Y染色体上，但是在雌蝇中也有截毛性状的表现，原因在于______。

填空题无论是短暂的和持久的母性影响，它们的遗传基础本质上都在于______基因的作用，其特点是父方的______推迟一代表现与分离。

填空题噬菌体的基因重组与______的重组过程不同，与______的重组十分相似。

填空题当位于同配性别染色体上的基因为纯合隐性，异配性别为显性时，F1代表现______遗传，F2代性别比为______，性状比为显性：隐性=______。

填空题噬菌体T4的形成是通过三条装配线汇合形成的，这三条装配线是______，______，______。

填空题人类中，下列细胞你能观察到多少条染色体?脑细胞______，红细胞______，极体______，精细胞______，次级卵母细胞______。

填空题植物的雄性不育系和保持系杂交得到______，与恢复系杂交得到______，而保持系自交得到______。

填空题用三隐性纯合体(aabbcc)与三对独立基因的杂合体(AaBbCc)测交，子代可能有______种表现型，其比例为______。若与三对连锁基因的杂合体(AaBbCc)进行杂交，若三对基因之间均为不完全连锁，且并发系数不为0，子代可能有______种表现型，并发系数为0时，子代有______种表现型。

填空题顺反子既有功能上的______，又有结构上的______。

填空题DNA作为遗传物质最早的证据来自肺炎链球菌的______实验。经加热杀死的S型细胞的某种物质使非致病的R型细胞转变为致病菌，这种现象称为______。

填空题人类体细胞中有______条染色体。在减数分裂形成配子时染色体组成情况：全部来源于父方的概率是______；全部来源于母方的概率是______；由父母双方的染色体组成的概率是______。