学年高二英语人教版必修8单元过关检测二 Word版含答案Word文档格式.docx

1、No two faces look exactly alike, making a human face as unique as a fingerprint. Genetics（遗传学） obviously play a major roleno two faces share the same DNA.But even in identical twins, there are still small differences in their appearances. So what is it that makes each face different?The answer lies

2、in a small piece of your DNA called a “gene enhancer”， according to a study published in Science. “There are thousands of enhancers in the human genome，” study leader Axel Visel，a researcher with Berkeley Lab. US. told Discovery.According to Visel, these DNA pieces act like switches, turning genes o

3、n and off and therefore determining whether a certain facial feature develops in a fetus（胎儿） while it is still in the womb（子宫）Whats interesting about gene enhancers is that they dont have to be found anywhere close to the genes they affect. They are able to control their targets from far away, which

4、 makes them even more influential.To test how powerful these special DNA pieces are in shaping the face，researchers deleted three of the gene enhancers in mice and compared them with normal mice at 8 weeks of age. The results showed that each enhancer deletion caused a distinct set of differences in

5、 the shape of the facefor example, causing an increase or decrease in facial length or width.In fact, scientists first noticed the existence of gene enhancers long ago, but they called them “junk DNA” back then because they didnt produce proteins and were thought to have no biological function. But

6、now “its increasingly clear that important functions are embedded in this junk” Visel told New Scientist.Understanding this may help scientists learn why and how things go wrong as a fetus develops, leading to facial birth defects（缺陷） such as cleft lips.Maybe gene enhancers also play a role.【语篇解读】为何

7、每个人都长得不一样？文章介绍了科学家们研究基因对于人们长相的影响的实验，解释了这一个问题。1What did Visels recent study uncover?AHow gene enhancers help shape the appearance of the face.BHow gene enhancers affect the growth of the fetus.CA new cure for facial birth defects.DThe connection between gene enhancers and genetic mutations（变异）解析：选A。主

8、旨大意题。本文主要回答的是第二段提出的问题：So what is it that makes each face different？研究发现，这主要是基因增强子的功劳，所以答案是A项。2What does the underlined word“embed” probably mean?ARoot. BFind.CAbsorb. DResearch.词义猜测题。根据上下文可知这句话的意思是：现在事实越来越清楚的显示出重要的功能就扎根于这种junk DNA中。embed和root的意思相近。故选A项。3Which of the following might be the best title

9、 for the passage?AGene Enhancers Affects Birth DefectsBFacing Gene EnhancersCThe Power of DNA PiecesDGene Enhancers Determines Your Personalities选B。标题归纳题。根据文章大意，作者主要是想介绍gene enhancer和人类面貌不同之间的关系。所以较为合适的题目是B项。B湖南十三校高三第一次联考）Sometimes people call each other “freakedcat”， but have you ever thought about

10、 this expression? When a cat is frightened, its heart starts beating faster, its muscles get tense, and there are changes in the chemicals in its bloodstream. Although the cat doesnt realize this, its body is getting ready for action.If the danger continues, the animal will do one of two things. It

11、will defend itself，or it will run away as fast as it can.Something like this also happens to people. When we are excited，angry, scared, or aroused by other emotions （feelings）, our bodies go through many physical changes. Our hearts beat faster, and our muscles get tense. All of these changes make u

12、s more alert and ready to react. We, too，get ready to defend ourselves or run.Human beings, however, have a problem that animals never face.If we give way to our feelings and let them take over, we can get into trouble. Have you ever said something in angeror hit somebodyand regretted it later? Have

13、 you ever shouted at a teacher，told somebody you were lonely, or said you were in love, and then wished later you had kept your mouth shut?It isnt always clever to express your feelings freely.Does this mean that its smarter always to hide our feelings? No! If you keep feelings of anger, sadness, an

14、d bitterness hidden away or bottled up inside, your body stays tense. Physical illness can develop. It can actually be bad for your health.（It isnt good to keep pleasant feelings inside either；all feelings need to be expressed.）Feelings that you keep all bottled up inside dont just go away.Its as if

15、 you bought some bananas and stuck them in a cupboard.You might not be able to see them，but before long youd smell them.And if you opened the cupboard，chances are that youd see little fruit flies flying all over them.Theyd be rotten.You can try to treat emotions as if they were bananas in the cupboa

16、rd.You can hide them and you can pretend they dont exist，but theyll still be around.And at last youll have to deal with them，just like those bananas.【语篇解读】本文主要用一只猫引出话题。人类把好的情绪或者坏的情绪藏在心里对身体没有好处。所有的情绪都需要表达。4The best title for this article is _AEmotions Affect Our BodiesBWhat Happens to A Frightened Ca

17、tCWhat Happens to An Excited PersonDFeelings That People Have本文主要介绍了情绪对我们身体的影响。随时表露自己的真实情感并不合适，但是总是把不良情绪压抑在心中害处更大。故本题选A项。5What does the word “freaked” mean in the first sentence?AExcited. BScared.CAngry. DShocked.从下文的When a cat is frightened，its heart starts beating faster，its muscles get tense，and

18、there are changes in the chemicals in its bloodstream.可知，这是指一只害怕的猫的表现。6If you hold in your feelings，_Agradually theyll disappearBthey wont exist any moreCthey will fly all overDyour body stays tense选D。细节理解题。从第五段的If you keep feelings of anger，sadness，and bitterness hidden away or bottled up inside，yo

19、ur body stays tense.可知答案。7The author wrote this article in order to _Atell us that it isnt good to keep feelings insideBgive us some advice on how to express our feelingsCmake us face the problem that we have to deal with feelingsDmake us know that it isnt always wise to express our feelings freely推

20、理判断题。文章的最后三段说的是不论好的情绪还是坏的情绪，都不能一直憋在心里，这样对身体很不好，也不是解决问题的办法。故A项为本题答案。CHave you ever heard of Florida pompano？Its a flat, silvery fish and very delicious! In fact, people who know a lot about fish say its one of the besttasting kinds of fish in the world to eat. Maybe thats one reason why it costs so m

21、uch to buy pompano（鲳参鱼） at the fish market or at a restaurant.Agricultural Research Service scientists in Florida are discovering many new and important secrets about this tasty fish. It lives in the warm waters off the Atlantic and Gulf coasts.The scientists are studying pompano. Because they want

22、fish farmers to be able to grow them in big tanks, somewhat the same way trout and catfish are grown in big outdoor ponds.Raising pompano in big tanks inland could help everyone be sure that there will always be lots of wild pompano in the sea. People could buy them from the fish farm instead of mos

23、tly only being able to buy pompano caught from the sea.Sometimes, if a fish is too popular, a problem called “overfishing” can happen. The fish could become harder and harder to find in the ocean. The fish might even disappear completely.The trouble with pompano is that no one really knows very much

24、 about how to grow big, healthy pompano in big tanks at a fish farm.Thats why scientists are trying to learn as much as they can about pompano. Maybe someday soon it will be easy to buy and eat pompano raised at fish farms, instead of pompano fished from the sea. When that happens, you may remember

25、this story about these scientists who helped find out how to raise delicious pompano in a new，Earthfriendly way.【语篇解读】本文是关于鲳参鱼的人工养殖问题。8Pompano costs so much to buy maybe because _Ait remains a secret for the scientistsBit cannot be raised in big tanks inlandCits the besttasting kinds of fish in the

26、worldDit lives warmly off the Atlantic and Gulf coasts根据题干中“costs so much to buy”定位到第一段的最后一句。得知其中一个原因可能是pompano是最好吃的鱼“之一”，可知C错。因此答案只能在后文，答案A、D都是文中的事实，但是却不是造成鱼贵的原因。而无法进行人工养殖最有可能造成鱼贵，故B为最佳答案。其中D的干扰性可能比较大。9Paragraph 4 mainly tells us raising pompano at fish farms _Amakes it easier to buy and eat the po

27、mpanoBprevents people catching pompano from the seaCstops people buying pompano caught from the seaDhelps make sure wild pompano will remain in the sea段落大意题。本段主要说明人工养殖pompano的必要性，它可以方便人们购买，但最重要的是它可以避免因过度捕捞而灭绝。根据instead of可知后文才是重点，故A所描述的只是事实细节。10The word “overfishing” in paragraph 5 means _A过度捕捞 B太受欢

28、迎C完全消失 D难以搜寻思路1：根据a problem called overfishing可知overfishing是一种问题，它会导致鱼类大量减少，甚至彻底消失。思路2：over表示比较程度差别关系是意为“超过，过度，太”：fish是捕鱼，人类的行为。11The best title of the passage may be “_”APompano: the tasty fishBSecrets of the big fishCA challenge: growing the big fishDThe way of raising the big fish选C。综合全文可知从第三段起直到

29、文章结束都在讲述这种鱼的人工养殖问题。DWhen it comes to artificial cloning，there are three different types：gene cloning, reproductive cloning and therapeutic cloning.Gene cloning produces copies of genes or segments of DNA.Reproductive cloning produces copies of whole animals. Therapeutic cloning produces embryonic st

30、em cells for experiments aimed at creating tissues to replace injured or diseased tissues.Gene cloning, also known as DNA cloning, is a very different process from reproductive and therapeutic cloning. Reproductive and therapeutic cloning share many of the same techniques, but are done for different

31、 purposes.Gene cloning is a carefully regulated technique that is largely accepted today and used routinely in many labs worldwide. However，both reproductive and therapeutic cloning raise important ethical issues，especially as related to the potential use of these techniques in humans.Reproductive cloning woul