Question 1

Figure 54.9  
-Which of the following is not a source of human-fixed nitrogen?

Accepted Answer

A) industrially produced fertilizers 
B) cultivation of soybeans 
C) combustion of fossil fuels 
D) irrigation agriculture 
A) industrially produced fertilizers 
B) cultivation of soybeans 
C) combustion of fossil fuels 
D) irrigation agriculture

Question 2

Figure 54.1
-How are the components in Figure 54.1 linked by the flow of energy?

Accepted Answer

The answer of Figure 54.1
-How are the components in Figure...

Question 3

Use the following information when answering the corresponding question(s).
Abstract:
Increased radiative forcing is an inevitable part of global climate change,yet little is known of its potential effects on the energy fluxes in natural ecosystems.To simulate the conditions of global warming,we exposed peat monoliths (depth,0.6 cm;surface area,2.1 m²)from a bog and fen in northern Minnesota,USA,to three infrared (IR)loading (ambient,+45,and +90 W m⁻²)and three water table (-16,-20,and -29 cm in bog and -1,-10 and -18 cm in fen)treatments,each replicated in three mesocosm plots.Net radiation (Rn)and soil energy fluxes at the top,bottom,and sides of the mesocosms were measured in 1999,five years after the treatments had begun.Soil heat flux (G)increased proportionately with IR loading,comprising about 3%-8% of Rn.In the fen,the effect of IR loading on G was modulated by water table depth,whereas in the bog,it was not.Energy dissipation from the mesocosms occurred mainly via vertical exchange with air,as well as the deeper soil layers through the bottom of the mesocosms,whereas lateral fluxes were 10- to 20-fold smaller and independent of IR loading and water table depth.The exchange with deeper soil layers was sensitive to water table depth,in contrast to G,which responded primarily to IR loading.The qualitative responses in the bog and fen were similar,but the fen displayed wider seasonal variations and greater extremes in soil energy fluxes.The differences of G in the bog and fen are attributed to differences in the reflectance in the long waveband as a function of vegetation type,whereas the differences in soil heat storage may also depend on different soil properties and different water table depth at comparable treatments.These data suggest that the ecosystem-dependent controls over soil energy fluxes may provide an important constraint on biotic response to climate change.
-The Noormets et al.study (2004)shows that there was an ecosystem-specific control over soil energy fluxes,and this constrained the biotic response to climate change.How do you think radiative heat would affect the water table in a wetland versus a temperate forest?

Accepted Answer

A) The wetland would likely absorb less heat than the temperate forest and therefore not significantly change water table depth. 
B) The wetland would likely absorb more heat than the temperate forest and significantly change water table depth. 
C) The temperate forest would likely absorb more heat than the wetland and significantly change water table depth. 
D) Both areas would absorb similar amounts of radiative heat and therefore affect the water table equally. 
A) The wetland would likely absorb less heat than the temperate forest and therefore not significantly change water table depth. 
B) The wetland would likely absorb more heat than the temperate forest and significantly change water table depth. 
C) The temperate forest would likely absorb more heat than the wetland and significantly change water table depth. 
D) Both areas would absorb similar amounts of radiative heat and therefore affect the water table equally.

Question 4

What do researchers typically focus on when they study a particular biogeochemical cycle?

Accepted Answer

A) the nature and size of the reservoirs 
B) the rate of element movement between reservoirs 
C) interaction of the current cycle with other cycles 
D) both the nature and size of the reservoirs,as well as the rate of element movement between reservoirs 
E) both the rate of element movement between reservoirs and the interaction of the current cycle with other cycles 
A) the nature and size of the reservoirs 
B) the rate of element movement between reservoirs 
C) interaction of the current cycle with other cycles 
D) both the nature and size of the reservoirs,as well as the rate of element movement between reservoirs 
E) both the rate of element movement between reservoirs and the interaction of the current cycle with other cycles

Question 5

Figure 54.4  
-What is the main reason for using food webs instead of food chains in analyzing ecosystems?

Accepted Answer

A) Most organisms eat more than one type of food. 
B) Most organisms feed at several trophic levels. 
C) The decomposition cycle needs to be shown. 
D) Most organisms eat more than one type of food and feed at several trophic levels. 
E) Most organisms eat more than one type of food and feed at several trophic levels.The decomposition cycle needs to be shown. 
A) Most organisms eat more than one type of food. 
B) Most organisms feed at several trophic levels. 
C) The decomposition cycle needs to be shown. 
D) Most organisms eat more than one type of food and feed at several trophic levels. 
E) Most organisms eat more than one type of food and feed at several trophic levels.The decomposition cycle needs to be shown.

Question 6

Figure 54.5  
-If plants in a northern temperate area use 26,400 kcal/m² of energy from solar radiation in photosynthesis,and the total amount of solar radiation energy reaching that area is 2,640,000 kcal/m²,what is the overall gross photosynthetic efficiency?

Accepted Answer

A) 0)01% 
B) 0)1% 
C) 1% 
D) 100% 
A) 0)01% 
B) 0)1% 
C) 1% 
D) 100%

Question 7

Figure 54.3  
-Considering its total area covered,which ecosystem type represented in Figure 54.3 has a very low level of economic impact on Earth's ecosystem?

Accepted Answer

A) tropical wet forest 
B) rock,sand,and ice 
C) tropical seasonal forest 
D) ocean neritic zone 
A) tropical wet forest 
B) rock,sand,and ice 
C) tropical seasonal forest 
D) ocean neritic zone

Question 8

Figure 54.5  
-After looking at Figure 54.5,what can be said about productivity in this ecosystem?

Accepted Answer

A) Nothing can be said based on this information. 
B) Between 80% and 90% of the energy is lost at the next highest trophic level. 
C) Between 10% and 20% of the energy is lost at the next highest trophic level. 
D) Productivity increases with each trophic level. 
E) Secondary consumers are more efficient than primary consumers at assimilating energy from the next lowest trophic level. 
A) Nothing can be said based on this information. 
B) Between 80% and 90% of the energy is lost at the next highest trophic level. 
C) Between 10% and 20% of the energy is lost at the next highest trophic level. 
D) Productivity increases with each trophic level. 
E) Secondary consumers are more efficient than primary consumers at assimilating energy from the next lowest trophic level.

Question 9

Figure 54.5  
-Plants never use 100% of the incoming solar radiation for photosynthesis on a yearly basis.What is a reasonable explanation for this?

Accepted Answer

A) Plants cannot photosynthesize during winter (in cold winter climates). 
B) Plants cannot photosynthesize on cloudy days. 
C) The pigments that drive photosynthesis respond to only a fraction of the wavelengths available,and plants cannot photosynthesize on cloudy days. 
D) The pigments that drive photosynthesis respond to only a fraction of the wavelengths available,and plants cannot photosynthesize during winter (in cold winter climates). 
E) The pigments that drive photosynthesis respond to only a fraction of the wavelengths available,and plants cannot photosynthesize during dry periods. 
A) Plants cannot photosynthesize during winter (in cold winter climates). 
B) Plants cannot photosynthesize on cloudy days. 
C) The pigments that drive photosynthesis respond to only a fraction of the wavelengths available,and plants cannot photosynthesize on cloudy days. 
D) The pigments that drive photosynthesis respond to only a fraction of the wavelengths available,and plants cannot photosynthesize during winter (in cold winter climates). 
E) The pigments that drive photosynthesis respond to only a fraction of the wavelengths available,and plants cannot photosynthesize during dry periods.

Question 10

Figure 54.9  
-Considering the global nitrogen cycle,how are humans altering this cycle?

Accepted Answer

A) industrial nitrogen fixation 
B) nitrogen lost to the atmosphere 
C) reduction of nitrogen available to terrestrial ecosystems 
D) reduction of nitrogen fixation by bacteria 
E) permanent burial of nitrogen in coastal environments through runoff 
A) industrial nitrogen fixation 
B) nitrogen lost to the atmosphere 
C) reduction of nitrogen available to terrestrial ecosystems 
D) reduction of nitrogen fixation by bacteria 
E) permanent burial of nitrogen in coastal environments through runoff

Question 11

Figure 54.7  
-Based on the experiment in Figure 54.7,all of the following are plausible reasons for the result except _____.

Accepted Answer

A) nutrients evaporate now that vegetation is absent 
B) nutrients dissolve in the water running through the watershed 
C) nutrients are attached to small particles of sand or clay that leave the watershed 
D) plant roots that held soil particles in place are no longer there 
A) nutrients evaporate now that vegetation is absent 
B) nutrients dissolve in the water running through the watershed 
C) nutrients are attached to small particles of sand or clay that leave the watershed 
D) plant roots that held soil particles in place are no longer there

Question 12

Figure 54.3  
-Which habitat types in Figure 54.3 cover the largest area?

Accepted Answer

A) tropical wet forest plus the ocean neritic zone 
B) open ocean 
C) algal beds and reefs plus the ocean neritic zone 
D) wetlands plus the ocean neritic zone 
A) tropical wet forest plus the ocean neritic zone 
B) open ocean 
C) algal beds and reefs plus the ocean neritic zone 
D) wetlands plus the ocean neritic zone

Question 13

Use the following information when answering the corresponding question(s).
Abstract:
Increased radiative forcing is an inevitable part of global climate change,yet little is known of its potential effects on the energy fluxes in natural ecosystems.To simulate the conditions of global warming,we exposed peat monoliths (depth,0.6 cm;surface area,2.1 m²)from a bog and fen in northern Minnesota,USA,to three infrared (IR)loading (ambient,+45,and +90 W m⁻²)and three water table (-16,-20,and -29 cm in bog and -1,-10 and -18 cm in fen)treatments,each replicated in three mesocosm plots.Net radiation (Rn)and soil energy fluxes at the top,bottom,and sides of the mesocosms were measured in 1999,five years after the treatments had begun.Soil heat flux (G)increased proportionately with IR loading,comprising about 3%-8% of Rn.In the fen,the effect of IR loading on G was modulated by water table depth,whereas in the bog,it was not.Energy dissipation from the mesocosms occurred mainly via vertical exchange with air,as well as the deeper soil layers through the bottom of the mesocosms,whereas lateral fluxes were 10- to 20-fold smaller and independent of IR loading and water table depth.The exchange with deeper soil layers was sensitive to water table depth,in contrast to G,which responded primarily to IR loading.The qualitative responses in the bog and fen were similar,but the fen displayed wider seasonal variations and greater extremes in soil energy fluxes.The differences of G in the bog and fen are attributed to differences in the reflectance in the long waveband as a function of vegetation type,whereas the differences in soil heat storage may also depend on different soil properties and different water table depth at comparable treatments.These data suggest that the ecosystem-dependent controls over soil energy fluxes may provide an important constraint on biotic response to climate change.
-Once heat is transferred to the soil,where does it go afterward (Noormets et al.2004)?

Accepted Answer

A) The heat is emitted back to the atmosphere. 
B) The heat is transferred to other soil layers. 
C) The heat is stored in the soil. 
D) The heat is both emitted back to the atmosphere and transferred to other soil layers. 
E) The heat is emitted back to the atmosphere,transferred to other soil layers,and stored in the soil. 
A) The heat is emitted back to the atmosphere. 
B) The heat is transferred to other soil layers. 
C) The heat is stored in the soil. 
D) The heat is both emitted back to the atmosphere and transferred to other soil layers. 
E) The heat is emitted back to the atmosphere,transferred to other soil layers,and stored in the soil.

Question 14

Figure 54.3  
-Which category in Figure 54.3 makes available the highest productivity per square meter?

Accepted Answer

A) tropical wet forest 
B) open ocean 
C) algal beds and reefs 
D) wetlands 
A) tropical wet forest 
B) open ocean 
C) algal beds and reefs 
D) wetlands

Question 15

Figure 54.4  
-Detritus can be consumed by which of the following primary decomposers?

Accepted Answer

A) bacteria 
B) archaea 
C) fungi 
D) earthworms 
E) all of the above 
A) bacteria 
B) archaea 
C) fungi 
D) earthworms 
E) all of the above

Question 16

Figure 54.8  
-Which of the following human activities is impacting the water cycle the least?

Accepted Answer

A) increase in asphalt and concrete surfaces 
B) conversion of grasslands and forests into agricultural fields 
C) increased processing of salt water to freshwater 
D) increases in irrigated agriculture 
A) increase in asphalt and concrete surfaces 
B) conversion of grasslands and forests into agricultural fields 
C) increased processing of salt water to freshwater 
D) increases in irrigated agriculture

Question 17

Figure 54.5  
-Why is energy lost when herbivores eat primary producers?

Accepted Answer

A) Primary producers have energy stored in indigestible substances. 
B) Primary producers cannot produce once eaten. 
C) Digestion takes place so rapidly that very little energy is absorbed. 
D) Most primary producers contain no usable energy for herbivores. 
A) Primary producers have energy stored in indigestible substances. 
B) Primary producers cannot produce once eaten. 
C) Digestion takes place so rapidly that very little energy is absorbed. 
D) Most primary producers contain no usable energy for herbivores.

Question 18

At the Hubbard Brook Experimental Forest in New Hampshire,how did large amounts of energy leave the decomposer food web?

Accepted Answer

A) Energy was lost through incomplete decomposition. 
B) Detritus was washed away into streams during heavy rain. 
C) Detritus was sublimated by increased solar radiation. 
D) Large numbers of decomposers emigrated from the area. 
A) Energy was lost through incomplete decomposition. 
B) Detritus was washed away into streams during heavy rain. 
C) Detritus was sublimated by increased solar radiation. 
D) Large numbers of decomposers emigrated from the area.

Question 19

You own 300 acres of patchy temperate forest.Which one of the following actions would increase the net primary productivity of the area the most?

Accepted Answer

A) adding fertilizer to the entire area 
B) introducing 100 rabbits into the area 
C) planting 500 new trees 
D) relocating all of the deer found in the area 
A) adding fertilizer to the entire area 
B) introducing 100 rabbits into the area 
C) planting 500 new trees 
D) relocating all of the deer found in the area

Question 20

Figure 54.6  
-Which of the following statements about secondary production is true?

Accepted Answer

A) Endotherms have higher metabolic rates compared to ectotherms and therefore have higher secondary production. 
B) Ectotherms have higher metabolic rates compared to endotherms and therefore have higher secondary production. 
C) Endotherms use less internal energy for metabolism and therefore have higher rates of secondary production. 
D) Ectotherms use less internal energy for metabolism and therefore have higher rates of secondary production. 
A) Endotherms have higher metabolic rates compared to ectotherms and therefore have higher secondary production. 
B) Ectotherms have higher metabolic rates compared to endotherms and therefore have higher secondary production. 
C) Endotherms use less internal energy for metabolism and therefore have higher rates of secondary production. 
D) Ectotherms use less internal energy for metabolism and therefore have higher rates of secondary production.

Exam 54: Ecosystems

Figure 54.9 -Which of the following is not a source of human-fixed nitrogen?

Figure 54.1 -How are the components in Figure 54.1 linked by the flow of energy?

What do researchers typically focus on when they study a particular biogeochemical cycle?

Figure 54.4 -What is the main reason for using food webs instead of food chains in analyzing ecosystems?

Figure 54.5 -If plants in a northern temperate area use 26,400 kcal/m² of energy from solar radiation in photosynthesis,and the total amount of solar radiation energy reaching that area is 2,640,000 kcal/m²,what is the overall gross photosynthetic efficiency?

Figure 54.3 -Considering its total area covered,which ecosystem type represented in Figure 54.3 has a very low level of economic impact on Earth's ecosystem?

Figure 54.5 -After looking at Figure 54.5,what can be said about productivity in this ecosystem?

Figure 54.5 -Plants never use 100% of the incoming solar radiation for photosynthesis on a yearly basis.What is a reasonable explanation for this?

Figure 54.9 -Considering the global nitrogen cycle,how are humans altering this cycle?

Figure 54.7 -Based on the experiment in Figure 54.7,all of the following are plausible reasons for the result except _____.

Figure 54.3 -Which habitat types in Figure 54.3 cover the largest area?

Figure 54.3 -Which category in Figure 54.3 makes available the highest productivity per square meter?

Figure 54.4 -Detritus can be consumed by which of the following primary decomposers?

Figure 54.8 -Which of the following human activities is impacting the water cycle the least?

Figure 54.5 -Why is energy lost when herbivores eat primary producers?

At the Hubbard Brook Experimental Forest in New Hampshire,how did large amounts of energy leave the decomposer food web?

You own 300 acres of patchy temperate forest.Which one of the following actions would increase the net primary productivity of the area the most?

Figure 54.6 -Which of the following statements about secondary production is true?

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Lipids, membranes, and the First Cells

Inside the Cell

Cell-Cell Interactions

Cellular Respiration and Fermentation

Photosynthesis

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

Analyzing and Engineering Genes

Genomics

Principles of Development

An Introduction to Animal Development

An Introduction to Plant Development

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Plants

Fungi

An Introduction to Animals

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Sensory Systems, signals, and Responses

Plant Reproduction

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Electrical Signals in Animals

Animal Sensory Systems and Movement

Chemical Signals in Animals

Animal Reproduction

The Immune System in Animals

An Introduction to Ecology

Behavioral Ecology

Population Ecology

Community Ecology

Biodiversity and Conservation Biology

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