2020军队职称英语理工类AB级模拟试题二(6)

"Hidden"Species May Be Surprisingly Common
Cryptic species animals that appear identical but are genetically quite distant一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.Mark Pfennninger and Klaus Schwenk,of the Goethe-Universitat in Frankfurt’s Germany,analyzed all known data on cryptic animal species aad discovered that they are found in equal proportions throughout all major branch,of the animal kingdom and occur in equal numbers in all biogeographical 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 he many different cryptic species that have low populations and are highly endangered,"says Henninger.Until the genetic information of all species'.in at least one texon 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`Intririo'.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 taxonumic 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 whom genetic differences that have evolved independently of each other and whose genetic differences can have significant consequences.
In the early 1900s misidentification 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 hav to know what you are dealing with,”Pfenninger said.Much previous research is now no longer used,he says,because it is not clear what species was studied.
1，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.
2.What was scientists'understanding of cryptic species?
A They occurred in equal numbers in all biogeographical regions
B They were mostly found in insects and reptiles.
C They were likely to be in tropical rather than temperate regions
D Both B and C
3,Do scientists know how many cryptic species exist?
A Not yet.
B Yes.they do.
C They will know the answer in another one or two years.
D They will never know the answer.
4.Which of the following about the African bush elephant and the African elephant is true?
A The WCU are interbreeding those elephants
B They are interbreeding species.
C They are two genetically distant species.
D They depend on each other for survival
5.People were confused in their attempts to control malaria in Europe in the early 1900s,because scientists
A identified only one mosquito species instead of six species.
B thought only three mosquito species transmitted disease.
C thought there was only on,mosquito species.
D did not know what species sees being studied.