The livelihood of each species in the vast and intricate assemblage of living things depends on the existence of other organisms. This interdependence is sometimes subtle, sometimes obvious. Perhaps the most straightforward dependence of one species on another occurs with parasites, organisms that live on or in other living things and derive nutrients, directly from them. The parasitic way of life is widespread. A multitude of microorganisms (including viruses and bacteria) and an army of invertebrates—or creatures lacking a spinal column (including crustaceans, insects and many different types of worms) — make their livings directly at the expense of other creatures. In the face of this onslaught, living things have evolved a variety of defense mechanisms for protecting their bodies from invasion by other organisms.
Certain fungi and even some kinds of bacteria secrete substances known as antibiotics into their external environment. These substances are capable of killing or inhibiting the growth of various kinds of bacteria that also occupy the area, thereby eliminating or reducing the competition for nutrients. The same principle is used in defense against invaders in other groups of organisms. For example, when attacked by disease-causing fungi or bacteria, many kinds of plants produce chemicals that help to ward off the invaders.
Members of the animal kingdom have developed a variety of defense mechanisms for dealing with parasites. Although these mechanisms vary considerably, all major groups of animals are capable of detecting and reacting to the presence of “foreign” cells. In fact, throughout the animal kingdom, from sponges to certain types of worms, shellfish, and all vertebrates (creatures possessing a spinal column), there is evidence that transplants of cells or fragments of tissues into an animal are accepted only if they come from genetically compatible or closely related individuals.
The ability to distinguish between “self”, and “nonself”, while present in all animals, is most efficient among vertebrates, which have developed an immune system as their defense mechanism. The immune system recognizes and takes action against foreign invaders and transplanted tissues that are treated as foreign cells.
1. What does the passage mainly discuss?
2. According to the passage, some organisms produce antibiotics in order to______.
3. According to the passage, a transplant of tissue between genetically incompatible organisms will result in the transplanted tissue ______.
4. According to the passage, the ability to distinguish between “self” and “nonself” enables vertebrates to ______.
5. All of the following are defined in the passage EXCERT ______.
6. The paragraph following the passage most probably discusses ______.
问题1选项
A.How parasites reproduce.
B.How organisms react to invaders.
C.How antibiotics work to cure disease.
D.How the immune systems of vertebrates developed.
问题2选项
A.prevent disease in humans
B.aid digestion
C.fight off other organisms
D.create new types of nutrients
问题3选项
A.becoming a parasite
B.being treated as an invader
C.altering its genetic makeup
D.developing a new immune system
问题4选项
A.accept transplanted cells.
B.detect and react to invasion
C.weaken their immune system
D.get rid of antibiotics
问题5选项
A.parasites
B.invertebrates
C.nutrients
D.vertebrates
问题6选项
A.how the immune system in vertebrates fights off foreign cells
B.different types of bacteria and fungi
C.how vertebrates and invertebrates differ
D.examples of different groups of organisms
第1题:B
第2题:C
第3题:B
第4题:B
第5题:C
第6题:A
第1题:
主旨大意题。这道题可以通过排除法来解决,A选项“寄生物是怎样繁殖的”与C选项“抗生素怎样治愈疾病”在文中都没有提及,故都不正确。由最后一段只是提及了脊椎动物形成了免疫系统与该免疫系统的作用,可知D选项“脊椎动物的免疫系统是怎样形成的”,不符合文章内容,可排除。文章主要讨论了机体如何对外来入侵者做出反应,由此分析知B选项“生物体对入侵者的反应”正确。因此B选项正确。
第2题:
细节事实题。由题干可以定位到文章第二段第二句中These substances are capable of killing or inhibiting the growth of various kinds of bacteria that also occupy the area, thereby eliminating or reducing the competition for nutrients.(这些物质可以杀死或抑制占领该地区的其他细菌的生长,进而消除或减少后者对营养物的竞争),由此分析四个选项中C选项“击退其他生物”符合文章内容。A选项“预防人类疾病”,文章没有提到此内容,可排除。B选项“帮助消化”,文章没有提到这种物质可以帮助消化,可排除。D选项“创造新的营养类型”,文章没有提到此内容,可排除。因此C选项正确。
第3题:
推理判断题。由题干可以定位到文章第三段最后一句中there is evidence that transplants of cells or fragments of tissues into an animal are accepted only if they come from genetically compatible or closely related individuals.(有证据表明,细胞或组织碎片移植到一种动物的身体上只有在该细胞或组织来自基因上兼容或关系密切的个体情况下才被接受),由题干中提及的between genetically incompatible organisms(在基因上不相容的生物之间)与文中的genetically compatible or closely related individuals(基因相容或关系密切的个体)条件相反,故可推测该结果是“不被接受或被当成入侵者”,由此分析知四个选项中B选项“被当成入侵者”符合文章内容。A选项“成为一个寄生虫”,文章没有提到此内容,可排除。C选项“改变其基因组成”,文章没有提到此内容,可排除。D选项“开发新的免疫系统”,文章没有提到此内容,可排除。因此B选项正确。
第4题:
细节事实题。由题干可以定位到文章最后一段最后一句中The immune system recognizes and takes action against foreign invaders.((脊椎动物形成的)免疫系统识别并对外来入侵者采取行动)。B选项“探测并对入侵做出反应”中的detect(探测)、react(应对)与文中的recognizes(识别)、takes action(采取行动)分别形成对应,由此分析知B选项正确。A选项“接受移植的细胞”,文章没有提到接受移植的细胞,可排除A选项。C选项“削弱他们的免疫系统”,文章没有提到此内容,可排除。D选项“不要使用抗生素”,文章没有提到此内容,可排除。因此B选项正确。
第5题:
推理判断题。A选项可以定位到文章第一段第二句中This interdependence is sometimes subtle, sometimes obvious. Perhaps the most straightforward dependence of one species on another occurs with parasites, organisms that live on or in other living things and derive nutrients, directly from them.(这种相互依赖有时很微妙,有时很明显。也许一个物种对另一个物种最直接的依赖发生在寄生虫身上,即寄生在其他生物上或体内并直接从其他生物获得营养的生物体),可以排除A选项“寄生虫”。B选项可以定位到文章第一段第四句invertebrates -or creatures lacking a spinal column.(无脊椎动物(即没有脊柱的生物)),可排除B选项“无脊椎动物”。D选项可以定位到文章第三段第三句中vertebrates(creatures possessing a spinal column,(脊椎动物(即拥有脊柱的生物)),可排除D选项“脊椎动物”。由此分析知C选项“营养盐”为该选项。因此C选项正确。
第6题:
推理判断题。通篇看全文,文章在最后一段才提出vertebrates(脊椎动物)的 The immune system(免疫系统);最后一段提及The immune system recognizes and takes action against foreign invaders and transplanted tissues that are treated as foreign cells.((脊椎动物形成的)免疫系统识别并对外来入侵者或被认为是外来细胞的被移植组织采取行动),根据一般常识,我们可以推测文章接下来可能讲“脊椎动物的免疫系统工作原理”,由此分析知A选项“脊椎动物的免疫系统是如何击退外来细胞的”正确。B选项“不同的细菌和真菌”,文章只是部分内容提到,可排除。C选项“脊椎动物和无脊椎动物有何不同”,不符合文章内容,可排除。D选项“不同生物体的例子”,不符合文章内容,可排除。因此A选项正确。