问答题Practice 2　　Transgenic plants and animals result from genetic engineering experiments in which genetic material is moved from one organism to another, so that the latter will exhibit a characteristic. Business corporations, scientists, and farmers hope

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Practice 2　　Transgenic plants and animals result from genetic engineering experiments in which genetic material is moved from one organism to another, so that the latter will exhibit a characteristic. Business corporations, scientists, and farmers hope that transgenic techniques will allow more cost-effective and precise plants and animals with desirable characteristics that are not available using up to date breeding technology.　　Transgenic techniques allow genetic material to be transferred between completely unrelated organisms.　　In order for a transgenic technique to work, the genetic engineer must first construct a transgene, which is the gene to be introduced plus a control sequence. When making a transgene, scientists usually substitute the original promoter sequence with one that will be active in the correct tissues of the recipient plant or animal.　　The creation of transgenic animals is one of the most dramatic advances derived from recombinant DNA technology. A transgenic animal results from insertion of a foreign gene into an embryo. The foreign gene becomes a permanent part of the host animals’ genetic material. As the embryo develops, the foreign gene may be present in many cells of the body, including the germ cells of the testis or the ovary. If the transgenic animal is fertile, the inserted foreign gene (transgene) will be inherited by future progeny. Thus, a transgenic animal, once created, can persist into future generations. Transgenic animals are different from animals in which foreign cells or foreign organs have been engrafted. The progeny of engrafted animals do not inherit the experimental change. The progeny of transgenic animals do.　　The techniques for creating a transgenic animal include the following: 1) picking a foreign gene, 2) placing the foreign gene in a suitable form called a “construct” which guides the insertion of the foreign gene into the animal genome and encourages its expression, and 3) injecting the construct into a single fertilized egg or at the very early embryo stage of the host animal. Much genetic engineering goes into the choice of a foreign gene and building a construct. The construct must have promoters to turn on foreign gene expression at its new site within the host animal genome. By choosing a particular promoter and splicing it in front of the foreign gene, we can encourage expression of our transgene within a specific tissue.　　One of the most important applications of transgenic animals is the development of new animal models of human disease. Transgenic animals can serve as models for many malignant tumors. Mice have been the most frequent hosts for transgenic modification, other domestic animals have also been used. One idea has been to create transgenic cows which secrete important pharmaceutical substances in their milk. Other attempts are being made to express human interferon in the milk of sheep.　　A transgenic crop plant contains a gene or genes which have been artificially inserted instead of the plant acquiring them through pollination. The inserted gene sequence (known as the transgene) may come from another unrelated plant, or from a completely different species: transgenic BT corn, for example, which produces its own insecticide, containing a gene from a bacterium. Plants containing transgenes are often called genetically modified or GM crops although in reality all crops have been genetically modified from their original wild state by domestication, selection and controlled breeding over long periods of time.

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相似问题和答案

第1题：

What is true about clone?()

A. It would be a completely new way of making a human being

B.It, biologically, refers to any organism whose genetic information is identical to that of its parent organism from which it is created

C.Cloning will create a baby from a single cell, from a single person

D.It is favored widely

正确答案：ABC

第2题：

most of australia’s unique plants and animals are imported from other continents. ()

参考答案：错误

第3题：

Find the word in the passage which means “ the movement from one place to another of a large group of animals” and write it down here: __________.

正确答案：
82. migration

第4题：

共用题干
Adaptation of Living Things
Certain animals and plants develop characteristics that help them cope with their environment better than others of their kind.This natural biological process is called adaptation.Among the superior characteristics developed through adaptation are those that may help in getting food or shelter,in providing protection,and in producing and protecting the young. That results in the evolution of more and more organisms（生物体）that are better fitted to their environments.
Each living thing is adapted to its way of life in a general way,but each is adapted especially to its own distinct class.A plant,for example,depends upon its roots to fix itself firmly and to
absorb water and inorganic chemicals（无机物）.It depends upon its green leaves for using the sun's energy to make food from inorganic chemicals.These are general adaptations,common to most plants .In addition,there are special adaptations that only certain kinds of plants have.
Many animals have adaptations that help them escape from their enemies.Some are hidden by their body color or shape,and many look like a leaf or a little branch.The coats of deer are colored to mix with the surroundings .Many animals .have the ability to remain completely still when an enemy is near.
Organisms have a great variety of ways of adapting.They may adapt in their structure,func-tion,and genetics;in their development and production of the young;and in other respects.An organism may create its own environment, as do warm-blooded mammals（哺乳动物）,which have the ability to adjust body heat exactly to maintain their ideal temperature despite changing weather.Usually adaptations are an advantage,but sometimes an organism is so well adapted to a particular environment that if conditions change,it finds it difficult or impossible to readapt to the new conditions.

Which of the following is NOT directly mentioned in the passage?
A: A living thing may adapt in its structure.
B: An organism may adapt in its function.
C: A living creature may adapt in its genetic makeup.
D: A living organism may adapt in its sleeping habit.

答案：D

解析：

根据文章的第一句话“Certain animals and plants develop characteristics that help them cope with their environment better than others of their kind.”可以比较容易地得出正确答案是C。

在不认识“environments”的情况下，我们可以通过上下文来猜侧该词的意思。根据第一段内容，主要讲什么是生物适应，其实根据常识也可以判断，适应无非是针对生存环境而言的，那么可以初步断定“environments”意为“环境”。而A项contexts意为“上下文，语境”，C项neighbors意为“邻居”,D项enemies意为“敌人”，都不符合题干要求。B项surroundings出现在倒数第二段“The coats of deer are colored to mix with the surroundings.”因此正确答案是B。

根据第三段的第二句“Some are hidden by their body color or shape, and many look like a leaf or a little branch.”可以判断，动物一般用羽毛或者体表颜色来达到把自己隐藏在环境中的目的，因此答案是D。

根据最后一段的第二句话“They may adapt in their structure, function, and genetics;” 可知，A、B、C三项都在文中直接被提到。

根据最后一段的第三句“An organism may create its own environment, as do warm-blooded mammals,which have the ability to adjust body heat exactly to maintain their ideal temperature despite changing weather.”可以比较容易地得出正确答案是A。

第5题：

The idea that some groups of people may be more intelligent than others is one of those hypotheses that dare not speak its name.But Gregory Cochran is 1 to say it anyway.He is that 2 bird,a scientist who works independently 3 any institution.He helped popularize the idea that some diseases not 4 thought to have a bacterial cause were actually infections,which aroused much controversy when it was first suggested.5 he,however,might tremble at the 6 of what he is about to do.Together with another two scientists,he is publishing a paper which not only 7 that one group of humanity is more intelligent than the others,but explains the process that has brought this about.The group in 8 are a particular people originated from central Europe.The process is natural selection.This group generally do well in IQ test,9 12-15 points above the 10 value of 100,and have contributed 11 to the intellectual and cultural life of the West,as the 12 of their elites,including several world-renowned scientists,13.They also suffer more often than most people from a number of nasty genetic diseases,such as breast cancer.These facts,14,have previously been thought unrelated.The former has been 15 to social effects,such as a strong tradition of 16 education.The latter was seen as a（an）17 of genetic isolation.Dr.Cochran suggests that the intelligence and diseases are intimately 18.His argument is that the unusual history of these people has 19 them to unique evolutionary pressures that have resulted in this 20 state of affairs.13选？

A.affirm
B.witness
C.observe
D.approve

答案：A

解析：

空前面总体谈到他们给西方文化做出了重大贡献，后面又有具体事实的列举（他们中出现了很多闻名世界的科学家），显然，事实是为了论证中心的，由此，只有A能表达语义，故正确答案为A。

第6题：

The supply chain is the flow of () and services from one business to another.

A、money

B、intermediate goods

C、EC

D、TPN

正确答案:B

第7题：

The ladder shall ______．

A.be secured in a position so that it rests firmly against the ship's side from which the discharge operations are carried out

B.have at least two replacement steps which are secured in position by a method different from that used in the original construction

C.have battens made of hardwood，or other material of equivalent properties，in one piece and not less than

D.have steps made of softwood，or other material of equivalent properties，made in one piece free of knots，having an efficient slip surface

正确答案：C

第8题：

Which of the following is the result of the volcanic eruption?

A. People stop traveling in Europe

B. Airlines suffer from the loss of planes

C. It becomes dangerous for animals to eat outside

D. Farmers have lost many of their animals

正确答案：C

第9题：

A.unique
B.particular
C.special
D.rare

答案：D

解析：

从文章内容看，显然该空填入的词应该是用来形容Cochran是一个什么样的人的。从上文我们可以看到，他总是做一些常人不敢做的事情，显然这个词既要表现他这类人很少，同时要表达出作者对Cochran正面评价，突出其优秀性，四个词中只有D能表达这种语义，故答案为D。本题从另一个角度来说，a rare bird是一固定搭配，指一类人。其他三个词与bird搭配都不能指人，同样得出答案为D。

第10题：

共用题干
Chimpanzees
1 Chimpanzees（黑猩猩）will soon be extinct（灭绝）.If the present rate of hunting and habitat（栖息地）destruction continues, then within 20 years, there will be no chimpanzees living in the wild. But this is more than an environmental or moral tragedy（悲剧）.Chimpan-zee extinction may also have profound implications（含意）for the survival of their distant relatives一human beings.
2 In 1975 the biologist Marie-Claire King and Allan Wilson discovered that the human and chimpanzee genomes（基因组）match by ovet 98%. Compare this to the mouse, used as model for human disease in lab tests,which shares only 60% of its DNA with us.In fact, chimpanzees are far more similar to humans than they are to any other species of monkey. As well as resembling us genetically,chimps are highly intelligent and able to use tools.These facts alone should be enough to make protection of chimps an urgent priority（优先）.But there is another,more selfish reason to preserve the chimp.
3 The chimpanzees' trump card（王牌）comes in the field of medical research. Chimpanzees are so similar to humans that veterinarians（兽医）often refer to human medical text-books when treating them. Yet chimpanzees do show differences in several key areas.In parti-cular,chimps are much more resistant to a number of major diseases.It is this ability that is so interesting.
4 For example,chimps seem to show a much higher resistance than humans to HIV,the virus that causes AIDS. Indeed,their use as experimental animals in AIDS research has de-dlined because they are so resistant.
5 By sequencing the chimp genome and pinpointing（找到）the place where the chimpanzee DNA sequence differs from that of humans,scientists hope to be able to discover which part of the genetic code gives chimps their increased resistance to some diseases. This,they hope,will allow them to develop new and more effective treatments for the human forms of these diseases. Such treatments could include the production of new drugs or even the alteration（改变）of the human genetic sequence. The recently completed human genome sequencing project has shown that such an effort is now well within our reach.

Paragraph 2______
A: Reasons for HIV Resistance
B: Implications of Chimpanzee Extinction for Humans
C: Effective AIDS Treatment
D: Genetic Similarities Between Chimps and Humans
E: Chimps'Resistance to HIV
F: Genetic Differences Between Chimps and Humans

答案：D

解析：

段落中出现了一个明显的段落主题词chimpanzees“黑猩猩”，除此以外，还有一个词extinct或extinction也可能是该段主题词，因为这个段落只有四个句子，而其中有两个句子分别含有extinct和extinction。备选项中选项B同时包含了这个词，而且选项B中的其他实义词implications , humans也在该段中出现了，因此B可能是答案。该段的主题句是段落最后一句，该句是个观点句，该句意为“黑猩猩的灭绝也可能对它们的远亲——人类的生存有着深远的意义”。这与选项B的意义一致：选项B意为“黑猩猩的灭绝对于人类的意义”，由此可以进一步确认答案为B。
段落中出现了一个明显的段落主题词chimpanzees“黑猩猩”，除此以外，还有一个词humans也可能是该段主题词，因为这个段落只有6个句子，而其中有3个句子都含有human。既含有human又含有chimpanzee（即chimp）的选项是D项“黑猩猩和人在遗传上的相似性”和F项“黑猩猩和人在遗传上的不同之处”，因此推测答案可能来自这两个选项（提示：备选项中如果出现了有关系的选项，如：正反意义项，意义相近项，结构相似项，则这些有关系的选项中通常会出现答案选项。）这两个选项的不同之处在于一个说相似，一个说不同。因此关注段落中主要谈的是相似还是不同。很容易在段落中注意到这样的结构：human and chimpanzee genomes（基因组）match by over 98%“人和黑猩猩的基因组相似度达到 98%以上”,chimpanzees are far more similar to humans than…“黑猩猩比……更像人”,resembling us geneticall广在遗传上与我们相似”，由此可知该段主要谈人和黑猩猩在遗传上的相似性，因此该题答案为D。
段落中出现了一个明显的段落主题词chimpanzees“黑猩猩”，但是依据该词并不能判断出答案。段落中出现了一个转折句（段落第三句），该句意为“然而，黑猩猩的确在几个重要的领域中呈现出不同”。（提示：段首处及段尾处出现的转折句可能就是该段主题句）该句意思与F项“黑猩猩和人在遗传上的不同之处”在意义呼应，因此F可能是答案。从该段主要内容来看，段落第二句提到黑猩猩与人类相似，甚至兽医为它们治疗时常常会参考人类的医学书籍，接下来用转折词yet(然而）话锋一转，对比性的提出该段的主题：黑猩猩和人确实有重要的不同之外。提出这个主题（也是该段的观点）之后，接下来对黑猩猩和人之间的不同进行了举例论证。接下来的句子提到“黑猩猩对许多重大疾病更具有抵杭力”，由此可进一步判断出该题答案为F。
段落中出现了一个明显的段落主题词AIDS“艾滋病”，选项C中含有 AIDS，但是选项C中的其他实义词effective“有效的”, treatment“治疗”没有在该段中直接地及间接地出现，因此选项C成为答案的可能性较小。其实该段中还有一个段落主题词resist-ance“抵杭力”或resistant“有抵抗力的”，选项A和选项E分别含有这两个词中的一个，因此这两个选项中可能出现答案选项。选项A意为“对艾滋病病毒有抵杭力的原因”，选项E意为 “黑猩猩对艾滋病病毒的抵抗力”。从该段主要内容来看，该段第一句提到黑猩猩对艾滋病病毒有更强的抵抗力，该段第二句（也是最后一句）说明因为黑猩猩对艾滋病病毒有很强的抵杭力，因此现在在艾滋病的研究实验中已经减少了对黑猩猩的使用。可见该段主要谈及的是黑程猩对艾滋病病毒的抵抗力，因此答案为E。
题干意为“黑猩程的灭绝可能会影响……”。利用题干中的细节信息短语 chimpanzee extinction“黑猩猩灭绝”作为定位线索，这样在第一段找到相关句：Chimpanzees （黑猩猩）will soon be extinct（灭绝）. If the present rate of hunting and habitat destruction continues,then within 20 years,there will be no chimpanzees living in the wild. But this is more than an environmental or moral tragedy. Chimpanzee extinction may also have profound implications for the survival of their distant relatives-human beings．相关句为第一段最后一句，该句意为“黑猩猩的灭绝也可能对它们的远亲―人类的生存有着深远的意义”。这表明黑猩猩的灭绝可能会对人类的生存产生影响，因此答案为C项“人类的生存”。
题干意为“在黑猩猩与……之间有不到2%的差异”。利用题干中的细节信息词/短语difference“差异”,less than 2%作为定位线索，这样在第二段找到相关句：In 1975 the biologists Marie-Claire King and Allan Wilson discovered that the human and chimpanzee genomes match（与difference呼应）by over 98%（与低于2%呼应）.Compare this to the mouse, used as model for human disease in lab tests,which shares only 60%of its DNA with us. In fact,chimpanzees are far more similar to humans than they are to any other species of monkey. As well as resembling us genetically,chimps are highly intelligent and able to use tools. These facts alone should be enough to make protection of chimps an urgent priority. But there is another,more selfish reason to preserve the chimp．相关句（第二段第一句）意为“1975年，生物学家Marie-Claire King和Allan Wilson发现人和黑猩猩的基因组匹配度达到了98%以上”，这意味着人和黑猩猩基因组之间的差异不到2%，因此答案为D项“人的基因组”。
题干意为“科学家们猜想基因在预防黑猩猩患……（疾病）方面起着显著的作用”。利用题干中的细节信息词/短语scientists“科学家”,genes“基因”,significant role“显著的作用”作为定位线索，这样在第五段找到相关句：By sequencing the chimp genome and pinpointing（找到）the place where the chimpanzee DNA sequence differs from that of humans, scientists hope to be able to discover which part of the genetic code（与gene呼应） gives chimps their increased resistance to some diseases.This,they hope,will allow them to develop new and more effective treatments for the human forms of these diseases.Such treat-ments could include the production of new drugs or even the alteration of the human genetic sequence. The recently completed human genome sequencing project has shown that such an effort is now well within our reach．相关句（第五段第一句）意为“通过对黑猩猩的基因组坝d序并找到黑猩猩的DNA序列与人类的DNA序列不同之处，科学家们希望能够发现哪部分遗传代码增强了黑猩猩抵御一些疾病的能力”，由此判断出B项“一些疾病”是答案。
题千意为“发现黑猩猩的遗传代码将有助于……”。利用题干中的细节信息词/短语discovery“发现”,genetic code“遗传代码”作为定位线索，这样在第五段找到相关句： By sequencing the chimp genome and pinpointing（找到）the place where the chimpanzee DNA sequencing differs from that of humans,scientists hope to be able to discover which part of the genetic code gi

问答题Practice 2　　Transgenic plants and animals result from genetic engineering experiments in which genetic material is moved from one organism to another, so that the latter will exhibit a characteristic. Business corporations, scientists, and farmers hope

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问答题Practice 2 Transgenic plants and animals result from genetic engineering experiments in which genetic material is moved from one organism to another, so that the latter will exhibit a characteristic. Business corporations, scientists, and farmers hope

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问答题Practice 2　　Transgenic plants and animals result from genetic engineering experiments in which genetic material is moved from one organism to another, so that the latter will exhibit a characteristic. Business corporations, scientists, and farmers hope