填空题成虫盘的预定性不是绝对的，预定性可以发生改变，这种现象被称为______。

填空题The first two stages in the development of civilized man were probably the invention of primitive weapons and the discovery of fire, although nobody knows exactly when he acquired the use of the latter. 41) ______ Animals have a few cries that serve as signals, but even the highest apes have not been found able to pronounce words, even with the most intensive professional instruction. The superior brain of man is apparently a necessity for the mastering of speech. When man became sufficiently intelligent, we must suppose that he gradually increased the number of cries for different purposes. It was a great day when he discovered that speech could be used for narrative. There are those who think that in this respect picture language preceded oral language. A man could draw a picture on the wall of his cave to show in which direction he had gone, or what prey he hoped to catch. 42) ______ Two important stages came not so long before the dawn of written history. The first was the domestication of animals; the second was agriculture. Agriculture made possible an immense increase in the number of the human species in the regions where it could be successfully practiced. 43) ______ 44) ______ These inventions and discoveries--fire, speech, weapons domestic animals, agriculture, and writing--made the existence of civilized communities possible. From about 3000 B. C. until the beginning of the Industrial Revolution less than two hundred years ago there was no technical advance comparable to these. During this long period man had time to become accustomed to his technique, and to develop the beliefs and political organizations appropriate to it. There was, of course, an immense extension in the area of civilized life. At first it had been confined to the Nile, the Euphrates, the Tigris, and the Indus, but at the end of the period in question it covered much the greatest part of the inhabitable globe. I do not mean to suggest that there was no technical progress during the time. 45) ______ (512 words)Notes: ape 猿。pastoral nomad 田园式的游牧部落的人。the Euphrates 幼发拉底河。the Tigris底格里斯河。the Indus 印度河。in question 所谈的(在名词后作后置定语)。[A] Probably picture language and. oral language developed side by side. I am inclined to think that language has been the most important single factor in the development of man.[B] Another fundamental technical advance was writing, which, like spoken language, developed out of pictures, but as soon as it had reached a certain stage, it was possible to keep records and transmit information to people who were not present when the information was given.[C] With the development of civilization, primitive people who lived in caves at that time badly needed a language, which would help them to communicate with one another.[D] The origin of language is also obscure. No doubt it began very gradually.[E] In fact, there was progress--there were even two inventions of very great importance, namely, gunpowder and the mariner's compass--but neither of these can be compared in their revolutionary power to such things as speech and writing and agriculture.[F] These were, at first, only those in which nature fertilized the soil after each harvest. Agriculture met with violent resistance from the pastoral nomads, but the agricultural way of life prevailed in the end because of the physical comforts it provided.[G] But industry was a step in human progress to which subsequently there was nothing comparable until our own machine age.

填空题某地区在建立工业区前后，灰色尺蛾与黑色尺蛾的比由95:5发展到5:95，产生这种现象的原因是______。

填空题人类珠蛋白基因可分为α珠蛋白基因簇和β珠蛋白基因簇。其中α珠蛋白基因簇位于______号染色体______臂，β珠蛋白基因簇位于______号染色体______臂。每种人体珠蛋白基因都有______个外显子和______个内含子。

填空题草履虫的放毒型遗传必须具备______和______两种因素的同时存在。

填空题上位效应可分为______和______。

填空题不少证据表明，在多细胞动物的发育中，每个细胞只表达了它整个______，而且不同类型的细胞只表达它整个______。

填空题叶绿体基因组含有大约______个基因。

填空题现已查明的细胞质基因的载体是______、______、______等。

填空题含29%腺嘌呤和29.5%尿嘧啶的病毒，其遗传物质的最大可能是：______。

填空题将基因型未知的显性个体与隐性纯合个体交配，以检测显性个体基因型的方法叫做______。

填空题假定母本的白花性状是细胞质基因决定的，父本的红花性状是它的相对性状，红花对白花为显性，当父本授粉给白花母本时，F1代的表现型为______。产生这一结果的细胞学原因是______。

填空题基因重组有时会出现异常分离比，这是由于基因转变造成的，目前能较好解释基因转变起源的理论是______。

填空题引物的RNA在合成后并不与模板分离，而是以______与模板结合，合成这种引物的酶称为______。

填空题染色体中参与复制的活性区呈“Y”形结构，称为______。

填空题重组能产生______中没有的新的类型。

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______。

填空题一对夫妇的孩子血型有A、B、AB、O，这对夫妇的血型是______和______。

填空题基因型为+s/c+的个体在减数分裂中有8%的性母细胞在s、c之间形成了一个交叉，那么，所产生的重组型配子各占______。

填空题大肠杆菌基因重组的特点有______、______、______。