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偶见种（rare species）
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"Hidden" Species May Be Surprisingly CommonCryptic species animals that appear identical but are genetically quite distant—may be much more widespread than previously thought. The findings could have major implications in areas ranging from biodiversity estimates and wildlife management, to our understanding of infectious diseases and evolution.Reports of cryptic species have increased dramatically over the past two decades with the advent of relatively inexpensive DNA sequencing technology. Markus Pfenninger and Klaus Schwenk, of the Goethe-Universitat, in Frankfurt, Germany, analyzed all known data on cryptic animal species and discovered that they are found in equal proportions throughout all major branches of the animal kingdom and occur in equal numbers in all biogeographieal regions.Scientists had previously speculated that cryptic species were predominantly found in insects and reptiles, and were more likely to occur in tropical rather than temperate regions. "Species that are seemingly widespread and abundant could in reality be many different cryptic species that have low populations and are highly endangered. " Says Pfenninger. Until the genetic information of all species in at least one taxon is thoroughly studied, no one will know just how many cryptic species exist. "It could be as high as 30%. " Pfenninger says."I'm extremely surprised by their results. " Says Alex Smith of the University of Guelph in Ontario, Canada. "It's a call to arms to keep doing the broad kind of genetic studies that we are doing. "Sampling as many individuals as possible, scientists hope to complete work on all fish and birds in another 5 to 10 years. Once either of these taxonomic groups is completed, Pfenninger says researchers will be able to decide how many cryptic species exist throughout the animal kingdom.Examples of cryptic species include the African elephant. A 2001 study found the elephants were actually two genetically distinct, non-interbreeding species, the African bush elephant and the African elephant. The species are currently listed as vulnerable and threatened, respectively, by the World Conservation Union (WCU).The reclassifications are more than an academic exercise. They define populations that have evolved independently of each other and whose genetic differences can have significant consequences. In the early 1900s misidentification of mosquito species based on morphology confused attempts to control malaria in Europe. Ultimately, what was thought to be a single species was actually made up of six sibling species, only three of which transmitted the disease. "The basic unit in biology is always the species, and you have to know what you are dealing with. " Pfenninger says. Much previous research is now no longer used, he says, because it is not clear what species was being studied.Which of the following about the significance of the research on cryptic species is NOT true?A．The results of the research can help the development of many other research areas.B．The results of the research can help the development of biodiversity estimates.C．The results of the research can help our understanding of infectious disease evolution.D．The results of the research can help our understanding of "survival of the fittest. "
考题
People are confused in their attempts to control malaria in Europe in the early 1900s, because scientists ______.A．identified only one mosquito species instead of six speciesB．thought only three mosquito species transmitted diseaseC．thought there was only one mosquito speciesD．did not know what species was being studied
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What is the root cause of desertification?A.poor farming
B.overpopulation
C.radical climate change
D.disappearance of rare plant species
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This rare bird has become（）Aan endangered specieBendangered speciesCendangering speciesDan endangered species
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This rare bird has become（）A、an endangered specieB、endangered speciesC、endangering speciesD、an endangered species
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数组data[m]为循环队列的存储空间，front为队头指针，rare为队尾指针，则执行入队的操作为（）A、rare=rare+1B、rare=（rare+1）%（m-1）C、rare=（rare-1）%mD、rare=（rare+1）%m
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单选题Which of the following can best summarize Sallon’s Plant Project?A
Discovering new species.B
Protecting rare species.C
Restoring extinct species.D
Reforming existing species.
考题
单选题数组data[m]为循环队列的存储空间，front为队头指针，rare为队尾指针，则执行入队的操作为（）A
rare=rare+1B
rare=（rare+1）%（m-1）C
rare=（rare-1）%mD
rare=（rare+1）%m
考题
单选题This rare bird has become（）A
an endangered specieB
endangered speciesC
endangering speciesD
an endangered species
考题
多选题Which two demonstrate an “is a” relationship？（）Apublic interface Person { } public class Employee extends Person { }Bpublic interface Shape { } public class Employee extends Shape { }Cpublic interface Color { } public class Employee extends Color { }Dpublic class Species { } public class Animal （private Species species；）Einterface Component { } Class Container implements Component （ Private Component[ ]children； ）
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单选题Which of the following is NOT mentioned in the last paragraph?A
Biologists began to study new species of turtles for Chinese food markets.B
Biologists discovered a few rare species of turtles as a result of search previouslyC
Some species of turtles will soon be extinct if they are caught and killed at the present speed.D
Turtles will soon be a target for rare collectors as dear as pearl and diamond.
考题
单选题Which of the following statements is closest in meaning to the passage you have just heard?A
The new vision of agriculture will support US expansion of power overseas.B
The new vision will enhance public health and social well-being.C
The new vision embraces technologies for the cloning of rare species of wildlife.D
The new vision promotes agriculture as a political, economic, social and environmental force.
考题
名词解释题偶见种或罕见种
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