首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Species interdependence in nature confers many benefits on the species involved, but it can also become a point of weakness when
Species interdependence in nature confers many benefits on the species involved, but it can also become a point of weakness when
admin
2011-02-10
28
问题
Species interdependence in nature confers many benefits on the species involved, but it can also become a point of weakness when one species involved in the relationship is affected by a catastrophe. Thus, flowering plant species dependent on insect pollination, as opposed to self- pollination or wind pollination, could be endangered when the population of insect-pollinators is depleted by the use of pesticides.
In the forests of New Brunswick, for example, various pesticides have been sprayed in the past 25 years in efforts to control the spruce budworm, an economically significant pest. Scientists have now investigated the effects of the spraying of Matacil, one of the anti-budworm agents that is least toxic to insect-pollinators. They studied Matacil’s effects on insect mortality in a wide variety of wild insect species and on plant fecundity, expressed as the percentage of the total flowers on an individual plant that actually developed fruit and bore seeds. They found that the most pronounced mortality after the spraying of Matacil occurred among the smaller bees and one family of flies, insects that were all important pollinators of numerous species of plants growing beneath the tree canopy of forests. The fecundity of plants in one common indigenous species, the red-osier dogwood, was significantly reduced in the sprayed areas as compared to that of plants in control plots where Matacil was not sprayed. This species is highly dependent on the insect-pollinators most vulnerable to Matacil. The creeping dogwood, a species similar to the red-osier dogwood, but which is pollinated by large bees, such as bumblebees, showed no significant decline in fecundity. Since large bees are not affected by the spraying of Matacil, these results add weight to the argument that spraying where the pollinators are sensitive to the pesticide used decreases plant fecundity.
The question of whether the decrease in plant fecundity caused by the spraying of pesticides actually causes a decline in the overall population of flowering plant species still remains unanswered. Plant species dependent solely on seeds for survival or dispersal are obviously more vulnerable to any decrease in plant fecundity that occurs, whatever its cause. If, on the other hand, vegetative growth and dispersal (by means of shoots or runners) are available as alternative reproductive strategies for a species, then decreases in plant fecundity may be of little consequence. The fecundity effects described here are likely to have the most profound impact on plant species with all four of the following characteristics, a short life span, a narrow geographic range, an incapacity for vegetative propagation, and a dependence on a small number of insect- pollinator species. Perhaps we should give special attention to the conservation of such plant species since they lack key factors in their defenses against the environmental disruption caused by pesticide use.
It can be inferred from the passage that which of the following plant species would be LEAST likely to experience a decrease in fecundity as a result of the spraying of a pesticide not directly toxic to plants? ______
选项
A、A flowering tree pollinated by only a few insect species.
B、A kind of insect-pollinated vine producing few flowers.
C、A wind-pollinated flowering tree that is short-lived.
D、A flowering shrub pollinated by a large number of insect species.
答案
C
解析
转载请注明原文地址:https://kaotiyun.com/show/p8cO777K
本试题收录于:
NAETI中级口译笔试题库外语翻译证书(NAETI)分类
0
NAETI中级口译笔试
外语翻译证书(NAETI)
相关试题推荐
Thepresidentofthecorporationsuggestedthatthephenomenashouldbe______andanalyzedintotheirsmallestpartsofelements
Allthemembersoftheboardproposedthatthemergershouldcancel.
Bush’sMBATwenty-sixof42presidents,includingBillClinton,werelawyers.Sevenweregenerals.GeorgeW.Bushbecomesthe
LikeDavidBrent,Bartnall’sbossonceharbored______tobesomethinginthemusicindustry.
Accordingtosomescientists,humanbeingsdopossesssomesuper-naturalpower.
There’sazaninessaboutbitcoin.Thecurrencyisbuiltonaweirdmixofthemostold-fashionedkindofspeculativegreed,bols
There’sazaninessaboutbitcoin.Thecurrencyisbuiltonaweirdmixofthemostold-fashionedkindofspeculativegreed,bols
Thegoodsareusuallyarrangedaccordingtotheircategoriessothatconsumerscanexpeditiouslyfindthattheywant.
Tothemajorityofus,musicisanindispensablepartofourdailylife.Itcanbedefinedinthisway,musicissoundarranged
随机试题
碳素钢、奥氏体不锈钢双面焊的焊接接头,其弯曲试验合格标准是弯曲角度为()。
低血钾时,静脉输液补钾一般不超过()
A.患者血压明显升高.体检:血压200/130mmHg(26.6/16.9kPa),眼底出血渗出、视乳头水肿。实验室报告:肾功能不全B.患者气急.端坐呼吸。体检:心脏扩大,听诊可闻及第四心音奔马律。双下肢浮肿,超声心动图报告:左心室腔明显扩大C.患者平
A.口渴喜饮B.大渴喜冷饮C.渴不欲饮D.大渴引饮,小便量多E.但欲漱水不欲咽热盛伤津可见
王某以借款纠纷为由起诉吴某,经审理,法院认为该借款关系不存在,王某交付吴某的款项为应支付的货款,王某与吴某之间存在买卖关系而非借用关系。法院向王某作出说明,但王某坚持已见。不予变更诉讼请求和理由。法院遂作出裁定,驳回王某的诉讼请求。关于本案,下列哪一说法是
甲乙丙三国相邻,后甲乙两国合并为丁国。如果有关各方之间没有新的相关协议达成。根据国际法中有关国家继承的规定,下列哪些事项是丁国应当继承的?()
在工程量清单的清单计价表格的内容中,()是指根据有关工程造价管理规定或省级以上政府职能部门规定必须缴纳,并应计入建筑安装工程造价的费用。
(2007年考试真题)对于已达到预定可使用状态但尚未办理竣工决算的固定资产、待办理竣工决算后,若实际成本与原暂估价值存在差异的,应调整已计提折旧。()
弗洛伊德认为人格结构由哪三部分组成?()
张教授:毕加索的每幅画都是杰作。李研究员:不对。有几幅达维和特莱克劳斯的绘画杰作也陈列在巴黎罗浮宫。李研究员显然认为张教授话中包含了以下哪项断定?
最新回复
(
0
)