[下载]2009.7月17日-8月RC机经（更新到8月11日20：45） 50篇

ashleyding

xiexie

NeilJ

blue grass那篇没加

vivian0331

5. 生态变化

在这里有个考点就是（After “initial invasion”, the shrub就开始怎么怎么抢水，蔓延，优势等等。。。）问，文中“initial invasion”打引号的原因是什么。应该是个结构题

大家说说文中“initial invasion”打引号的原因是什么

utility80

9月17日，准备裸考，谢谢楼主先

yvonne_grape

希望小女子还没有迟来.LZ真详细,连anchoret的看法都有,太经典了!!!!狂顶!!!!太感谢了

vivian0331

LZ mm看看这个能不能提供些参考：

http://forum.chasedream.com/dispbbs.asp?boardID=22&ID=399437&page=1

aldkayx

帮朋友搜集jj，CD帮了不少忙。为了回馈，我找到一个好像是jj 31原文的，请nn确定一下：）

31. ants, aphid在milkweed上生长

Machiavellian Milkweed Doesn’t Play Fair with its Insect Partners

Who’s the boss? Milkweed is the boss.

Milkweed plants engage in a helpful bit of mutualism with the aphids and ants who take up residence on them. Aphids feed on the milkweed’s sap, then secrete honeydew, which ants eat. The ants, in turn, are the muscle of the operation—they help both the plants and the aphids by fighting off potential predators like caterpillars. The partnership goes three ways, but the power is not equal—milkweed is in control.

Researchers Kailen Mooney and Anurag Agrawal recently found that the milkweed can manipulate the relationship between ants and aphids, altering the dynamics for its own good. The scientists planted 32 groups of milkweed, with each group containing 10 siblings from the same family, in a field full of ants. In 20 of the 32 milkweed groups, the presence of ants was a big boon for aphids—the aphid population increased by 150 percent compared to plants with no ants to protect them. But in the other 12 groups, the numbers of aphids actually decreased by more than half when ants were around.

So why should the three-way arrangement benefit all parties in most cases, but not in others? Since the researchers divided milkweed into groups according to genetic families, they say the plants’ genetics must be controlling the relationship. Mooney and Agrawal aren’t exactly sure how, but they speculate that the composition of milkweed sap can vary from family to family. Perhaps some families of milkweed just didn’t need as much protection, and therefore allowed fewer aphids to live on them by producing a less inviting sap. After all, this arrangement is not free for the plants—they give up lots of sugar and water for the aphids to live on the plant and induce the ants to come.

However it happens, the scientists say, finding that plants can manipulate the ant-aphid relationship helps to explain why the numbers of aphids and ants can vary so much between one plant and another, a problem that had puzzled biologists before. Now they know—milkweed is making a power grab.

ly1st

JJ23 Ants of colony考古及相关资料

JJ23 关于蚂蚁

【版本1】一篇是讲ant 的nomadic pattern和什么pattern的，没看懂。
   

【版本2】03/11 VERBAL碰上两道机经阅读，一个蚂蚁那个。
   

第一段说蚂蚁分两种习性，不冬眠的时候怎样怎样，冬眠的时候怎样怎样。
   

第二段解释说蚂蚁这种习性可能是跟它生在什么时候有关系，蚁后生很多小蚂蚁幼虫，有的在不冬眠的时候发展成大蚂蚁，就变成了类似工兵蚂蚁，可能是，有的在冬眠的时候发育，就变成什么什么蚂蚁。文章不长，但是生词很多，看着晕。题目有一道推断题，问第二段说如果工兵蚂蚁不在不冬眠的时候发育会变成什么样。
   

【版本3 V38, 74】03/17
  ant 那一道：3道题目
   

虽然只有两段，但还是觉得有点小tricky,也可能是我最后做这一篇时间很紧吧. ant, stetey(?) phrase 和 nomatic phrase

1.问primary purpose JJ作者的答案：注意，第一段有提到一个earlier observation, 作者对这个是做了补充，而非反驳或什么的. 所以选项选有supplement
  的那一项
   

2.文章最后一句话高光，问目的。JJ作者：是讲ant 完成nomatic phrase后会到达steery, 选项里有一项是evidence to support the conclusion that nomatic period is linked to reproductive cycle. JJ中没有提到的关键词：nomatic period is linked with reproductive cycle.这是作者在第一段末尾说的
   

3.是nomatic phase 和stetery 期间ant 行为的比较，主要在第二段定位。我做时有点晕。有pupae,好像是这词，我也不知道是什么意思
   

有益补充：google 出来的
  有点像  里面还有说SP和NP两个阶段   大家可以搜一下
   

Nomadic behavior of the army ant Neivamyrmex nigrescens was studied in a desert-grassland habitat. Six colonies were followed through eight nomadic phases (94 nomadic days) while direction and distance of emigrations, growth of larvae, number of adults and larvae per colony were determined.

In all colonies, the nomadic phase began when newly enclosed adults and small larvae were present, and ended when the larvae were fully grown. Average emigration distance was positively related to number of larvae in the colony. These findings support Schneirla's theory that brood stimulation is a proximate cause of the nomadic phase.

Failures to emigrate were equally likely at all points in the nomadic phase, and there was no systematic increase in emigration distance as the phase progressed. These findings do not support Schneirla's version of brood-stimulative theory.

Number of adults per colony was positively related to the directionality of the nomadic phase; however, both the direction and distance of emigrations varied unpredictably from one nomadic day to the next, in marked contrast to predictions from optimal foraging theory.

Schneirla's theory is useful in predicting phase differences in colony behavior, but it does not account for characteristics such as frequency, direction, or distance of emigrations within the nomadic phase. These aspects of nomadic behavior are more closely related to characteristics of the habitat such as prey density and availability of nest sites. Army ant nomadism in this habitat may depart from the optimum because of high prey density, small colony size, or lack of nesting sites.

有益补充2：蚂蚁那篇，有解释 statary phase, 凑合着用！（感谢黄GG）
   

Eciton
   army ants have a bi-phasic lifestyle where they alternate between a nomadic phase and a stationary stage. In the stationary or statary phase ('statary' is an old English word meaning "to stand in place"), which lasts about three weeks, the ants remain in the same location every night. They make a nest out of their own bodies, protecting the queen and her eggs in the middle. This temporary home is known as a bivouac. In the nomadic phase the ants move their entire colony to a new location nearly every night for two weeks.

When the ants first enter the statary phase, the queen's body swells massively and she lays as many as 250,000 eggs in less than a week. While the eggs mature, the ants swarm with less frequency and intensity. When the eggs hatch, the excitement caused by the increased activity of the larvae causes the colony to enter the nomadic phase. The colony swarms much more intensely and nearly every day, and the ants move to a new location every night. After two weeks, around the time when the larvae begin to pupate, the colony again enters the statary phase, and the cycle begins anew (Schneirla, 1971).

还有一些Google资料，很详细，大家可以看看！

在美洲大陆大约有150种行军蚁，它们全部属于游蚁族（Ecitonini）。其中本属的Eciton burchelli和Eciton hamatum最为常见研究得也最多
     

    游蚁的活动呈现周期性，一般一个周期可以分为两个时期。
     

    一个是比较稳定的时期（statary phase，“statary”是一个比较古老的英文单词，大概就是“呆在那里”的意思。）这个时期大约要持续3周，此时蚂蚁每晚在同一个地方宿营。工蚁们用自己的身体抱成团状巢，蚁后和幼虫等在中央。这样的营地被称作bivouac。
     

    当蚁群进入这个时期时，蚁后的腹部迅速膨大，在短短不到一周的时间内产会下大约25万枚卵。在卵成熟时，蚁群活动相对较少。一旦卵孵化, 整个蚁群便立即兴奋起来，于是……蚁群进入了下一个时期，一个游猎时期（nomadic phase）。在将近两周的时间内它们不断的变换宿营地。游猎中的蚁群具有惊人的杀伤力，它们所向披靡，几乎消灭任何比它们跑得慢的动物。由于游蚁在当地生态中扫荡性的影响力，一些昆虫和鸟类演化出了和游蚁非常复杂的关系。一些拟蚁甲虫跟随蚂蚁大军进行部猎，它们捕猎由于受到蚁群攻击而受伤或逃跑的昆虫。还有一些昆虫干脆模拟蚂蚁幼虫在蚁群中骗吃骗喝了此一生。大约有10种鸟类部分或全部的依靠游蚁大军获取食物。其中一些鸟类每日清晨寻找到游蚁部队后赶到部队的先头，捕食因被游蚁趋赶而逃散虫

xxxyyyxxx

感谢吧 还有那个WJY-SQL 童鞋

Mellisaisis

太感谢大家啦！我７号北美考试，不知道结果会怎样？第一次考的超烂，彻底伤透啦我的心．阿弥陀佛，希望这次会好＞＿＜　虽然不知道结果如何，还是要再次谢谢各位的．