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题库 / OG2018-RC-467
Resin is a plant secretion that hardens when exposed to air; fossilized resin is called amber. Although Pliny in the first century recognized that amber was produced from “marrow discharged bytrees,” amber has been widely misunderstood to be a semiprecious gem and has even been described in mineralogy textbooks. Confusion also persists surrounding the term “resin,” which was defined before rigorous chemical analyses were available. Resin is often confused with gum, a substance produced in plants in response to bacterial infections, and with sap, an aqueous solution transported through certain plant tissues. Resin differs from both gum and sap in that scientists have not determined a physiological function for resin.
In the 1950s, entomologists posited that resin may function to repel or attract insects. Fraenkel conjectured that plants initially produced resin in nonspecific chemical responses to insect attack and that, over time, plants evolved that produced resin with specific repellent effects. But some insect species, he noted, might overcome the repellent effects, actually becoming attracted to the resin. This might induce the insects to feed on those plants or aid them in securing a breeding site.Later researchers suggested that resin mediates the complex interdependence, or“coevolution,” of plants and insects over time. Such ideas led to the development of the specialized discipline of chemical ecology, which is concerned with the role of plant chemicals in interactions with other organisms and with the evolution and ecology of plant antiherbivore chemistry (plants' chemical defenses against attack by herbivores such as insects).
According to the passage, which of the following is true of plant antiherbivore chemistry?
Changes in a plant's antiherbivore chemistry may affect insect feeding behavior.
A plant's repellent effects often involve interactions between gum and resin.
A plant's antiherbivore responses assist in combating bacterial infections.
Plant antiherbivore chemistry plays only a minor role in the coevolution of plants and insects.
Researchers first studied repellent effectsin plants beginning in the 1950s.
文章大意：
研究对象：resin（树脂）以及石化的树脂amber（琥珀）
研究问题：resin（的功能）是啥
研究结果：
1. amber一直被误解为是一种宝石；resin和gum、sap傻傻分不清楚，因为不知道resin的功能是什么
2. 1950s：resin是用来抵制/吸引昆虫的。
发展过程：nonspecific response → specific repellent effect → 调节植物和昆虫的共同进化。
题目分析：
文章细节题：关于plant antiherbivore chemistry（PAC），以下哪点是对的？
原文：之后研究学家认为，resin调和了复杂的植物昆虫的共同进化关系。这一观点促进了化学生态学的发展；
化学生态学是研究植物化学物质对其他有机体以及PAC的影响的；
PAC：植物生产的、用来抵抗食草动物（如昆虫）的物质。
选项分析：
A选项：正确。PAC的改变会影响昆虫的进食行为：PAC会抵抗食草动物，所以PAC对食草动物的进食行为产生影响（有PAC，昆虫就无法吃这个植物）。
B选项：植物的趋避效果（repellent effect）通常涉及到gum和resin的相互作用：第一段提到gum用来抵制细菌感染，但没有提到gum和PAC的联系。
C选项：PAC是为了与抵制细菌感染：gum的作用才是抵制细菌感染。
D选项：PAC在植物昆虫的共同进化中只起到很小的作用：第二段提到PAC在化学生态学中起到重要作用，而化学生态学主要研究植物昆虫的共同进化。
E选项：学者首次研究植物的趋避效果是在1950s：1950s的时候学者推断resin的作用是抵制或吸引昆虫，但没有提是不是第一次。
Fraenkel conjectured that plants initially produced resin...he noted, might overcome the repellent effects, actually becoming attracted to the resin.
我觉得答案是这两句话给出的，overtime，plant's antiherbivore chemistry 发生变化produce resin with specific repellent effects -》导致some insects become attracted to the resin而不是被repell（insect feeding behavior发生变化）
E选项：学者首次研究植物的趋避效果是在1950s：1950s的时候学者推断resin的作用是抵制或吸引昆虫，但没有提是不是第一次。
gum, a substance produced in plants in response to bacterial infections,
Such ideas led to the development of the specialized discipline of chemical ecology, which is concerned with the role of plant chemicals in interactions with other organisms and with the evolution and ecology of plant antiherbivore chemistry (plants' chemical defenses against attack by herbivores such as insects).
E（研究者最开始在1950年开始研究植物的防御，这个和AC无关）
第一段论点：amber has been widely misunderstood to be a semiprecious gem，围绕论点展开两个confusion-gum and sap; 不同于两个迷惑点的physiological function for resin没被确认；
第二段论点：resin may function to repel or attract insects，分别降repel and attract，指出发展出一个具体的学科，专门研究植物化学和其它机体的互动，以及在反食草动物化学的进化
定位：plants' chemical defenses against attack by herbivores such as insects
错选e，beginning 没有提到，排除
over time, plants evolved that produced resin with specific repellent effects.
最重要的是这一句，evolve就是表示改变，再看后一句就是改变后对昆虫的影响。
第一段，解釋何謂樹脂，還有琥珀（化石樹脂）表示它常被誤認為礦石。樹脂也常被跟樹膠或樹液混淆，但其實三者生理功能並不相同。第二段，1950年代昆蟲學家假定樹脂能夠擊退或吸引昆蟲，並表示樹脂的分泌一開始只是為了擊退昆蟲，但某些昆蟲因為能夠抵禦樹脂衷的化學成分而演化成會被樹脂吸引。最後，說明這些昆蟲與植物有協同進化coevolution的傾向，會促進chemical ecology領域中針對特定學科（antiherbivore）研究的發展。
第二段讲的一大堆就是第一句话讲的“ resin may function to repel or attract insects”。后面好几句话都是解释：植物本来是在nonspecific的情况下产生resin，后来随时间的推移，就在specific的情况下产生resin。第三句话也是在说有些本来repel的昆虫现在是attract。接下来两句话也是在解释attract。最后才说这种现象有利于某个学科的发展。
其实不用搞懂中间说的这么多，只要找到第二段第一句话的论点就好了。
(plants' chemical defenses against attack by herbivores such as insects).
说明这个chemistry是研究植物对昆虫的抵抗能力的，所以antiherbivore chemistry的成功与否会影响植物对昆虫的抵抗能力，从而影响昆虫的觅食习惯。
这篇基本没看懂，但是定位应该在全文最后一句。剩下的选项都不靠边。
看选项：
B：gum and resin第二段没有提到
C：A plant's antiherbivore responses有助于抵抗细菌的感染。似乎没有说到细菌
D：minor role没有体现，原文是and连接，没有比较。
E：这个看起来就不对劲，first在哪里？没有体现
再想想A，比较贴近原文。。。18年新题，还求各路大神给解析
2017-7-3
第二段说resin功能到底是驱赶还是吸引虫子？Fraenkel说：一开始nonspecific，后来specific，但是，一些虫子会overcome repellent，变成attracted。这样：rein会导致虫子feed on those plants。然后提出specialized discipline of chemical ecology，后面定语从句用and连接了plant antiherbivore chemistry。
做题的时候，从关键词plant antiherbivore chemistry开始，原文能看出这个和前面的东西是并列修饰一个什么ecology的，再往前找，原来是一个什么ideas导致了这个ecology，再往前，就能看到feeding相关的东西。这时候已经晕了。
看选项：
小哥哥真可爱。我也是这样晕的。。
哈哈哈，希望我写出来对别人都帮助~
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