12月GMAT阅读新题最终版——Natural Science Division（1）.

2017-08-11 作者： 184阅读

　　2.1. Biology

　　2.1.1雌性动物or昆虫hexapod/insect

　　说有些动物是雄性动物做主导的，通常是雄性求偶时会以食物源的信息作为求偶资本,后某同学研究说也有些物种的雄性是以能保护雌性免受捕食者的侵害来作为求偶资本的。最后说该同学的研究有待进一步证明什么的。

　　变种文章，估计不是同一篇：

　　P1 说达尔文进化论说在配对上雌性一般散发一种东西来吸引雄性，因为女虫子会很多精力哺育，所以男虫子对男女之事offspring必须给与更多地关注(costly)。因此一般都是女虫子给男虫子发信号，因为发信号的(母的)安全，接收信号并寻找(公的)的危险(可能会暴露在捕食者监视下)。

　　P2 是另外两个人做的实验，举了两个种类的生物都是雄性散发来吸引雌性，有的虫子男的给女的发信号。一个叫G的专家解释说：这可能是因为当找食物和找男虫子同样危险时，女虫子就啥也不怕了。所以有男虫子发求爱信号一般都会附加点其它好处，比如告诉女虫子敌人在哪里或者是事物在哪里。由此问为什么，(答案是雄性散发的东西包含了一种信息说它具有对于雌性有valid的东西，就是附加点好处，才会把雌性吸引过来。)

　　同时文章提出研究还不能确定法信号的男虫子是否拥有食物。

　　有主旨题~ 介绍一个理论，提出并解释一个不同的新理论?虫子的发信息的不同?

　　2.1.3 Antagonistic symbiosis shrimp和sea butterfly

　　Antagonistic symbiosis

　　P1 写的是发现H.Ditata shrimp的动物有一个奇怪的行为，他们会把sea butterfly背在背上什么的，说这样会减少HD动物的行动力让他们降低捕食能力并且更容易被捕食(这里有一道细节题，问A动物这种行为会是自己产生什么后果，A:it will be more subject to predation. E: it will not move as quickly as it could.主要就是这两个中间一个。应该是A吧?

　　P 2 写的好像是一个实验科学家做了一个实验，把专门吃HD的鱼和HD还有seabutterfly放在一起，结果鱼不敢吃HD。后来就得出结论，说seabutterfly会释放一种化学物质来保护HD

　　P 3 是高亮，就是解释这种现象的，说了这个现象跟之前发现的symbiosis的3种分类都不符合(双赢的Mutualism，一个受益一个受害的Parasitism寄生，还有Commensalism共生)，列出了3种分类，然后给出一个新的分类叫antagonistic symbiosis

　　Q1 symbiosis的3种分类都不符合?什么来的?

　　Q2 最后一段的作用? 解释了一种新的category 的产生?

　　Q3 有个infer 题就是通过HA不是 1 或2 种寄生你能得出神马结论Lz选的是一个得利另一个不受伤害??? 具体看选项.

　　Q4 框架：提出现象，解释现象，总结新category

　　Q5 主旨题全文应该是解释了一种phenomenon//category???

　　The nature of this relationship is puzzling. It is difficult to discern how carrying another organism around can be advantageous. We speculated that in fact, amphipods must be considerably slowed down. By carully measuring the swimming speeds of amphipods with and without sea butterflies, we found that amphipods carrying sea butterflies moved only half as quickly as similarly sized solitary amphipods. The situation simply made no sense. In reducing their mobility, the amphipods became more vulnerable to predators and less adept at capturing prey. Why, then, would amphipods go out of their way to abduct and carry sea butterflies?

　　Our experiments clearly demonstrated that something about the sea butterflies was repelling the fish, and we suspected that this deterrence was chemical. To find out, we conducted a second set of feeding experiments. We homogenized the sea butterflies and mixed the homogenate with fish-meal powder to make food pellets. As a control, we also made food pellets containing just the fish-meal powder. We offered both the experimental and the control pellets to fish, which always ate the control pellets and always rejected the pellets containing the homogenate. This provided compelling evidence that compounds might be responsible for the feeding chemical deterrence.

　　中间删去一段~没什么用

　　Our experiments demonstrated to us that the sea butterfly C. antarctica synthesizes a deterrent substance that the amphipod H. dilatata exploits for its own protection. This unique association - the abduction of one species by another - is unprecedented in the annals of behavioral and chemical ecology. Some decorator crabs are chemical ecology known to cover their upper carapace with a variety of objects, including the occasional sponge that might harbor densive chemistry. But this appears to be a nonselective behavior. Crabs haphazardly decorate themselves with whatever is at hand.

　　The association between the sea butterfly and the amphipod falls within the dinition of symbiosis共生, where two dissimilar species live together in an intimate association. However, none of the relationships dined within the broad context of symbiosis - parasitism, comensalism or mutualism - appear to suitably describe the sea butterfly-amphipod relationship.

　　Parasitism寄生 implies that one species associates with another to the detriment伤害 of one of them. Often, the parasite feeds off the tissues or body fluids of its host. Mutualism共生 describes a relationship where both species benit from the association. Commensalism describes organisms that live in benign and neutral中立or良性 association with one another. Neither of the latter two interactions appropriately describes what we have observed, and parasitism provides only a very weak analogy to it. We feel that a new term might be needed to describe the "antagonistic symbiosis" that seems to describe most accurately this unique interaction.

　　寄生:一个伤害另一个，吃对方组织和体液。共生:双方都获利。commensalism共栖:中立，互相不干扰。实际(如果加上下一段的文章): 一个获利，另一个间接受害,若没有下面这段,得看选项怎么说了.网上的定义是the association is disadvantageous or destructive to one of the organisms, but ordinarily it is used of cases where the association is advantageous, or often necessary, to one or both, and not harmful to either.

　　In this association the antagonist benits greatly from the relationship. Remember that the amphipod must sacrifice its mobility and speed. Clearly the dense it acquires offsets these drawbacks. The sea butterfly, on the other hand, is at the mercy of the amphipod. While it is being carried around, it cannot feed to sustain its energy【Seabutterfly很惨.没得吃饭】

12月GMAT阅读新题最终版——Natural Science Division（1）12月GMAT阅读新题最终版——Natural Science Division（1）