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Exam 20: Communities and Ecosystems

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Question 1

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What is one way in which energy flow differs from chemical cycling?

A) Energy flow is unidirectional; chemical elements can be recycled.
B) Energy can enter but cannot leave an ecosystem; chemical elements can leave but cannot enter an ecosystem.
C) Energy flows from lower to higher trophic levels; chemicals cycle from higher to lower trophic levels.
D) Energy can both enter and leave an ecosystem; chemical elements always remain within a single ecosystem.

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Question 2

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Species found in only one place on Earth are called ________ species.

A) hot spot
B) exotic
C) keystone
D) endemic

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Question 3

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Use the following information to answer the following questions. Malaria is an infectious disease caused by a unicellular eukaryotic organism belonging to the genus Plasmodium.These eukaryotic organisms are transmitted from one person to another by the female Anopheles mosquito when it feeds on human blood.Within humans,the Plasmodium species destroy red blood cells and,without effective treatment,serious infections can lead to death.Currently,more than 400 million people are afflicted with malaria and between 1 and 3 million people die from it each year.Historically,a chemical compound called quinine has been used in developing effective drugs against malaria.In its natural environment,quinine is produced by certain trees native to South America.This chemical is synthesized in the outer layer of tree trunks and acts as an herbivore deterrent. -Despite being used for many years,quinine-based drugs have not led to the eradication of malaria and currently there are parasites that are resistant to the compound.Which of the following were likely important in the development of this resistance to quinine?

Which type of ecosystem has low primary production but nonetheless contributes a large proportion of Earth's total net primary production?

The present rate of species loss ________.

Small areas that have a large number of endangered and threatened species are referred to as ________.

Modern conservation science increasingly aims at ________.

Use the following information to answer the following questions. Malaria is an infectious disease caused by a unicellular eukaryotic organism belonging to the genus Plasmodium.These eukaryotic organisms are transmitted from one person to another by the female Anopheles mosquito when it feeds on human blood.Within humans,the Plasmodium species destroy red blood cells and,without effective treatment,serious infections can lead to death.Currently,more than 400 million people are afflicted with malaria and between 1 and 3 million people die from it each year.Historically,a chemical compound called quinine has been used in developing effective drugs against malaria.In its natural environment,quinine is produced by certain trees native to South America.This chemical is synthesized in the outer layer of tree trunks and acts as an herbivore deterrent. -Based on the relationship between Plasmodium spp.and humans,Plasmodium would be considered ________.

Several years ago,I was crossing the border from Canada to the United States and I had a bag of Washington State apples with me.The customs officer at the border would not let me take the apples with me into the United States (and I really hated the idea of getting rid of a bag of perfectly good apples) .Why did the customs officer refuse to allow me to cross the border with my apples?

Plants can most readily utilize the ________ form of nitrogen.

An example of a mutualism,or +/+ relationship,is ________.

Which of these organisms convert atmospheric nitrogen gas to a form that can be utilized by plants?

Which of these convert organic matter to inorganic matter by breaking down dead organisms?

Please refer to the following art to answer the following questions. -The figure below shows the growth curves of two populations of Paramecium,P.aurelia and P.caudatum.From the data,we can conclude that ________.

On average,what percentage of the energy in one trophic level becomes incorporated into the next higher trophic level?

The rate at which an ecosystem's producers convert solar energy to chemical energy stored in biomass is called ________.

Most decomposers are ________.

A regional assemblage of interacting ecosystems is a ________.

Besides the atmosphere,abiotic reservoirs of carbon dioxide include ________.

One problem with eradicating invasive species is that sometimes the disturbed area is unable to be colonized by native species.For example,in forests where the invasive plant garlic mustard has been removed,native plants and animals do not recolonize because they are extinct in that patch of forest.How should restoration ecologists increase species diversity and recover ecosystem function?