Question 1

The earliest known measurable increase in the oxygen concentration of Earth's atmosphere resulted from activity caused by early

Accepted Answer

A)  land plants. 
B)  human agriculture. 
C)  photosynthetic bacteria. 
D)  anaerobic prokaryotes. 
E)  eukaryotic ocean phytoplankton. 
A)  land plants. 
B)  human agriculture. 
C)  photosynthetic bacteria. 
D)  anaerobic prokaryotes. 
E)  eukaryotic ocean phytoplankton.

Question 2

Which example best describes both an elemental pool where an element accumulates and an elemental sink where it is removed from circulation and locked up for long periods?

Accepted Answer

A)  Calcium in bones,which remains fairly stable throughout an animal's life 
B)  Nitrogen that is made available to plants from their bacterial endosymbionts 
C)  Fossil fuel deposits in which carbon is stored for hundreds of millions of years 
D)  Atmospheric oxygen levels,which are maintained stable by photosynthesis 
E)  Sulfur compounds,which react with water to produce acid precipitation 
A)  Calcium in bones,which remains fairly stable throughout an animal's life 
B)  Nitrogen that is made available to plants from their bacterial endosymbionts 
C)  Fossil fuel deposits in which carbon is stored for hundreds of millions of years 
D)  Atmospheric oxygen levels,which are maintained stable by photosynthesis 
E)  Sulfur compounds,which react with water to produce acid precipitation

Question 3

What is the relationship between the processes of nitrogen fixation and denitrification?

Accepted Answer

A)  Both processes move nitrogen from land to oceans. 
B)  Both processes release nitrogen into the atmosphere. 
C)  Both processes remove nitrogen from the atmosphere. 
D)  Denitrification takes nitrogen from the air and makes it usable by plants;nitrogen fixation reverses this process. 
E)  Nitrogen fixation takes nitrogen from the air and makes it usable by plants;denitrification reverses this process. 
A)  Both processes move nitrogen from land to oceans. 
B)  Both processes release nitrogen into the atmosphere. 
C)  Both processes remove nitrogen from the atmosphere. 
D)  Denitrification takes nitrogen from the air and makes it usable by plants;nitrogen fixation reverses this process. 
E)  Nitrogen fixation takes nitrogen from the air and makes it usable by plants;denitrification reverses this process.

Question 4

Scientists currently estimate NPP using which type of measurement?

Accepted Answer

A)  Wavelengths of light reflected from Earth's surface 
B)  Amount of nitrogen fixation 
C)  Atmospheric O2 concentrations 
D)  Atmospheric CO2 concentrations 
E)  Total yearly plant biomass 
A)  Wavelengths of light reflected from Earth's surface 
B)  Amount of nitrogen fixation 
C)  Atmospheric O2 concentrations 
D)  Atmospheric CO2 concentrations 
E)  Total yearly plant biomass

Question 5

Which of these possible changes in the global water cycle is least likely to occur as a direct result of global warming?

Accepted Answer

A)  Higher evaporation rates 
B)  Greater percentage of rain compared to snow 
C)  More water stored in ice caps and glaciers 
D)  Earlier spring snowmelt and spring flooding 
E)  Changes in severity and patterns of precipitation 
A)  Higher evaporation rates 
B)  Greater percentage of rain compared to snow 
C)  More water stored in ice caps and glaciers 
D)  Earlier spring snowmelt and spring flooding 
E)  Changes in severity and patterns of precipitation

Question 6

Which series represents the correct ranking of average NPP,from greatest to smallest?

Accepted Answer

A)  Marsh $\rightarrow$river $\rightarrow$ estuary 
B)  Marsh $\rightarrow$ estuary$\rightarrow$ river 
C)  Estuary $\rightarrow$ marsh $\rightarrow$ river 
D)  Estuary $\rightarrow$ river $\rightarrow$marsh 
E)  River $\rightarrow$ estuary $\rightarrow$ marsh 
A)  Marsh $\rightarrow$river $\rightarrow$ estuary 
B)  Marsh $\rightarrow$ estuary$\rightarrow$ river 
C)  Estuary $\rightarrow$ marsh $\rightarrow$ river 
D)  Estuary $\rightarrow$ river $\rightarrow$marsh 
E)  River $\rightarrow$ estuary $\rightarrow$ marsh

Question 7

Based on current knowledge,how are extreme weather events expected to affect species and communities in the coming years?

Accepted Answer

A)  There may be major disruptions,as many impacted species will go extinct. 
B)  There may be some major disruptions due to sudden shifts in community composition. 
C)  There will likely be little impact because there will be fewer extreme weather events. 
D)  There will likely be little impact because species and communities are already adapted and will recover quickly. 
E)  There may be minor disruptions but most species and communities will adapt quickly to changed conditions. 
A)  There may be major disruptions,as many impacted species will go extinct. 
B)  There may be some major disruptions due to sudden shifts in community composition. 
C)  There will likely be little impact because there will be fewer extreme weather events. 
D)  There will likely be little impact because species and communities are already adapted and will recover quickly. 
E)  There may be minor disruptions but most species and communities will adapt quickly to changed conditions.

Question 8

Approximately what percentage of the total water on Earth is found in the oceans?

Accepted Answer

A)  70% 
B)  80% 
C)  90% 
D)  97% 
E)  99% 
A)  70% 
B)  80% 
C)  90% 
D)  97% 
E)  99%

Question 9

At times in the geologic past,five climate changes have resulted in extinction of large numbers of species at approximately the same time.These incidents are known as _______ extinctions.

Accepted Answer

The answer of At times in the geologic past,five climate...

Question 10

The rate of nitrogen recycling is slowest when the nitrogen is located in which global pool?

Accepted Answer

A)  Terrestrial soils 
B)  Marine biomass 
C)  Terrestrial plant biomass 
D)  Benthic sediments and rocks 
E)  Nitrogen dissolved in ocean water 
A)  Terrestrial soils 
B)  Marine biomass 
C)  Terrestrial plant biomass 
D)  Benthic sediments and rocks 
E)  Nitrogen dissolved in ocean water

Question 11

Use the following to answer questions :
Refer to the diagram below.[Note: Pools of carbon in the compartments and annual fluxes are given in units of 10S1U1P115S1S1P0 grams.]  
-Calculate the total mean carbon flux into the atmosphere over land (in 1015 grams).

Accepted Answer

Question 12

Water's high heat capacity and its ability to change state (from solid to liquid to gas)at Earth temperatures makes it an important medium for transferring _______ around Earth.

Accepted Answer

The answer of Water's high heat capacity and its ability...

Question 13

Studies done between 1960 and 1994 showed an increased oscillation in seasonal levels of atmospheric CO2.Which factor might be implicated in these increases?

Accepted Answer

A)  Longer growing seasons,leading to greater total summer photosynthesis 
B)  Longer growing seasons,leading to greater photosynthesis in the tropics 
C)  Increased global use of nitrogen fertilizers,leading to more eutrophication 
D)  More global droughts,leading to worldwide decreases in photosynthesis 
E)  More severe storms,leading to greater variations in photosynthesis and respiration 
A)  Longer growing seasons,leading to greater total summer photosynthesis 
B)  Longer growing seasons,leading to greater photosynthesis in the tropics 
C)  Increased global use of nitrogen fertilizers,leading to more eutrophication 
D)  More global droughts,leading to worldwide decreases in photosynthesis 
E)  More severe storms,leading to greater variations in photosynthesis and respiration

Question 14

Primary production in the ocean occurs only in the top layers;production at lower levels is limited by _______.

Accepted Answer

The answer of Primary production in the ocean occurs only...

Question 15

Slightly more carbon dissolves into the ocean than leaves it by outgassing.This occurs because some carbon compounds enter ocean sediments due to the force of _______.

Accepted Answer

The answer of Slightly more carbon dissolves into the ocean...

Question 16

As of July 2013,what was the approximate concentration of CO2 in the atmosphere?

Accepted Answer

A)  190 ppm 
B)  225 ppm 
C)  280 ppm 
D)  330 ppm 
E)  399 ppm 
A)  190 ppm 
B)  225 ppm 
C)  280 ppm 
D)  330 ppm 
E)  399 ppm

Question 17

Before the Industrial Revolution,the concentration of CO2 in Earth's atmosphere was 265 parts per million (ppm).At the end of 2012,the concentration was 393 parts per million.Given the correlation of atmospheric CO2 concentration with global temperature rise,what does this change suggest about the global carbon budget?

Accepted Answer

A)  It is balanced;CO2 concentration is not related to the global carbon budget. 
B)  It is balanced;rises in CO2 concentrations measured in ppm will have no effect. 
C)  It is unbalanced;CO2 is entering the atmosphere much faster than it can be removed. 
D)  It is unbalanced;CO2 is being removed from the atmosphere much faster than it can enter. 
E)  It is unbalanced,but the imbalance is insignificant because the tiny CO2 concentrations will have no effect. 
A)  It is balanced;CO2 concentration is not related to the global carbon budget. 
B)  It is balanced;rises in CO2 concentrations measured in ppm will have no effect. 
C)  It is unbalanced;CO2 is entering the atmosphere much faster than it can be removed. 
D)  It is unbalanced;CO2 is being removed from the atmosphere much faster than it can enter. 
E)  It is unbalanced,but the imbalance is insignificant because the tiny CO2 concentrations will have no effect.

Question 18

What is the relationship between the processes of photosynthesis and respiration in the global carbon cycle?

Accepted Answer

A)  Both photosynthesis and respiration cycle carbon through organic pools. 
B)  Both photosynthesis and respiration cycle carbon through inorganic pools. 
C)  Photosynthesis moves carbon from organic to inorganic pools;respiration does the opposite. 
D)  Photosynthesis moves carbon from inorganic to organic pools;respiration does the opposite. 
E)  Photosynthesis occurs primarily over land;respiration occurs primarily over the oceans. 
A)  Both photosynthesis and respiration cycle carbon through organic pools. 
B)  Both photosynthesis and respiration cycle carbon through inorganic pools. 
C)  Photosynthesis moves carbon from organic to inorganic pools;respiration does the opposite. 
D)  Photosynthesis moves carbon from inorganic to organic pools;respiration does the opposite. 
E)  Photosynthesis occurs primarily over land;respiration occurs primarily over the oceans.

Question 19

Inability of a species to adapt to environmental changes results in _______ of the species.

Accepted Answer

The answer of Inability of a species to adapt to...

Question 20

Greenhouse gases,such as CO2 and CH4,are currently entering the atmosphere in greater amounts than are leaving it.Explain the process that occurs when these greenhouse gases build up in the atmosphere.

Accepted Answer

A build-up of greenhouse gases (GHGs)res

Exam 45: The Global Ecosystem

The earliest known measurable increase in the oxygen concentration of Earth's atmosphere resulted from activity caused by early

Which example best describes both an elemental pool where an element accumulates and an elemental sink where it is removed from circulation and locked up for long periods?

What is the relationship between the processes of nitrogen fixation and denitrification?

Scientists currently estimate NPP using which type of measurement?

Which of these possible changes in the global water cycle is least likely to occur as a direct result of global warming?

Which series represents the correct ranking of average NPP,from greatest to smallest?

Based on current knowledge,how are extreme weather events expected to affect species and communities in the coming years?

Approximately what percentage of the total water on Earth is found in the oceans?

At times in the geologic past,five climate changes have resulted in extinction of large numbers of species at approximately the same time.These incidents are known as _______ extinctions.

The rate of nitrogen recycling is slowest when the nitrogen is located in which global pool?

Use the following to answer questions : Refer to the diagram below.[Note: Pools of carbon in the compartments and annual fluxes are given in units of 1015 grams.] -Calculate the total mean carbon flux into the atmosphere over land (in 1015 grams).

Water's high heat capacity and its ability to change state (from solid to liquid to gas)at Earth temperatures makes it an important medium for transferring _______ around Earth.

Studies done between 1960 and 1994 showed an increased oscillation in seasonal levels of atmospheric CO2.Which factor might be implicated in these increases?

Primary production in the ocean occurs only in the top layers;production at lower levels is limited by _______.

Slightly more carbon dissolves into the ocean than leaves it by outgassing.This occurs because some carbon compounds enter ocean sediments due to the force of _______.

As of July 2013,what was the approximate concentration of CO2 in the atmosphere?

What is the relationship between the processes of photosynthesis and respiration in the global carbon cycle?

Inability of a species to adapt to environmental changes results in _______ of the species.

Greenhouse gases,such as CO2 and CH4,are currently entering the atmosphere in greater amounts than are leaving it.Explain the process that occurs when these greenhouse gases build up in the atmosphere.

Introduction

The Chemistry and Energy of Life

Nucleic Acids, Proteins, and Enzymes

Cells: the Working Units of Life

Cell Membranes and Signaling

Pathways That Harvest and Store Chemical Energy

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

DNA and Its Role in Heredity

From Dna to Protein: Gene Expression

Regulation of Gene Expression

Genomes

Biotechnology

Genes, Development, and Evolution

Processes of Evolution

Reconstructing and Using Phylogenies

Speciation

The History of Life on Earth

Bacteria, Archaea, and Viruses

The Origin and Diversification of Eukaryotes

The Evolution of Plants

The Evolution and Diversity of Fungi

Animal Origins and Diversity

The Plant Body

Plant Nutrition and Transport

Plant Growth and Development

Reproduction of Flowering Plants

Plants in the Environment

Fundamentals of Animal Function

Nutrition and Digestion

Breathing

Circulation

Muscle and Movement

Neurons, Sense Organs, and Nervous Systems

Nervous and Endocrine Control

Water and Salts: Excretion

Animal Reproduction

Animal Development

Immunology: Animal Defense Systems

Animal Behavior

The Distribution of Earths Ecological Systems

Populations

Ecological and Evolutionary Consequences of Interactions Within and Among Species

Ecological Communities

Filters

Use the following to answer questions : Refer to the diagram below.[Note: Pools of carbon in the compartments and annual fluxes are given in units of 10¹⁵ grams.] -Calculate the total mean carbon flux into the atmosphere over land (in 10¹⁵ grams).

Studies done between 1960 and 1994 showed an increased oscillation in seasonal levels of atmospheric CO₂.Which factor might be implicated in these increases?

As of July 2013,what was the approximate concentration of CO₂ in the atmosphere?

Greenhouse gases,such as CO₂ and CH₄,are currently entering the atmosphere in greater amounts than are leaving it.Explain the process that occurs when these greenhouse gases build up in the atmosphere.