Question 1

The Hubbard Brook watershed deforestation experiment yielded all of the following results except:

Accepted Answer

A)  Most minerals were recycled within a forest ecosystem. 
B)  The flow of minerals out of a natural watershed was offset by minerals flowing in. 
C)  Deforestation increased water runoff. 
D)  The nitrate concentration in waters draining the deforested area became dangerously high. 
E)  Calcium levels remained high in the soil of deforested areas. 
A)  Most minerals were recycled within a forest ecosystem. 
B)  The flow of minerals out of a natural watershed was offset by minerals flowing in. 
C)  Deforestation increased water runoff. 
D)  The nitrate concentration in waters draining the deforested area became dangerously high. 
E)  Calcium levels remained high in the soil of deforested areas.

Question 2

A cow's herbivorous diet indicates that it is a(n)

Accepted Answer

A)  primary consumer. 
B)  secondary consumer. 
C)  decomposer. 
D)  autotroph. 
E)  producer. 
A)  primary consumer. 
B)  secondary consumer. 
C)  decomposer. 
D)  autotroph. 
E)  producer.

Question 3

Which of the following ecosystems would likely have a larger net primary productivity/hectare, and why?

Accepted Answer

A)  open ocean because of the total biomass of photosynthetic autotrophs 
B)  a temperate grassland because of the small standing crop biomass that results from consumption by herbivores and rapid decomposition 
C)  tropical rain forest because of the high species diversity 
D)  cave due to the lack of photosynthetic autotrophs 
E)  tundra because of the incredibly rapid period of growth during the summer season 
A)  open ocean because of the total biomass of photosynthetic autotrophs 
B)  a temperate grassland because of the small standing crop biomass that results from consumption by herbivores and rapid decomposition 
C)  tropical rain forest because of the high species diversity 
D)  cave due to the lack of photosynthetic autotrophs 
E)  tundra because of the incredibly rapid period of growth during the summer season

Question 4

Which of the following lists of organisms is ranked in correct order from lowest to highest percent in production efficiency?

Accepted Answer

A)  mammals, fish, insects 
B)  insects, fish, mammals 
C)  fish, insects, mammals 
D)  insects, mammals, fish 
E)  mammals, insects, fish 
A)  mammals, fish, insects 
B)  insects, fish, mammals 
C)  fish, insects, mammals 
D)  insects, mammals, fish 
E)  mammals, insects, fish

Question 5

To recycle nutrients, an ecosystem must have, at a minimum,

Accepted Answer

A)  producers. 
B)  producers and decomposers. 
C)  producers, primary consumers, and decomposers. 
D)  producers, primary consumers, secondary consumers, and decomposers. 
E)  producers, primary consumers, secondary consumers, top carnivores, and decomposers. 
A)  producers. 
B)  producers and decomposers. 
C)  producers, primary consumers, and decomposers. 
D)  producers, primary consumers, secondary consumers, and decomposers. 
E)  producers, primary consumers, secondary consumers, top carnivores, and decomposers.

Question 6

Which of the following is an example of an ecosystem?

Accepted Answer

A)  all of the brook trout in a 500-square-hectare river drainage system 
B)  the plants, animals, and decomposers that inhabit an alpine meadow 
C)  a pond and all of the plant and animal species that live in it 
D)  the intricate interactions of the various plant and animal species on a savanna during a drought 
E)  all of the organisms and their physical environment in a tropical rain forest 
A)  all of the brook trout in a 500-square-hectare river drainage system 
B)  the plants, animals, and decomposers that inhabit an alpine meadow 
C)  a pond and all of the plant and animal species that live in it 
D)  the intricate interactions of the various plant and animal species on a savanna during a drought 
E)  all of the organisms and their physical environment in a tropical rain forest

Question 7

Which of these ecosystems has the lowest net primary production per square meter?

Accepted Answer

A)  a salt marsh 
B)  an open ocean 
C)  a coral reef 
D)  a grassland 
E)  a tropical rain forest 
A)  a salt marsh 
B)  an open ocean 
C)  a coral reef 
D)  a grassland 
E)  a tropical rain forest

Question 8

In the nitrogen cycle, the bacteria that replenish the atmosphere with N2 are

Accepted Answer

A)  Rhizobium bacteria. 
B)  nitrifying bacteria. 
C)  denitrifying bacteria. 
D)  methanogenic protozoans. 
E)  nitrogen-fixing bacteria. 
A)  Rhizobium bacteria. 
B)  nitrifying bacteria. 
C)  denitrifying bacteria. 
D)  methanogenic protozoans. 
E)  nitrogen-fixing bacteria.

Question 9

The major role of detritivores in ecosystems is to

Accepted Answer

A)  provide a nutritional resource for heterotrophs. 
B)  recycle chemical nutrients to a form capable of being used by autotrophs. 
C)  prevent the buildup of the organic remains of organisms, feces, and so on. 
D)  return energy lost to the ecosystem by other organisms. 
A)  provide a nutritional resource for heterotrophs. 
B)  recycle chemical nutrients to a form capable of being used by autotrophs. 
C)  prevent the buildup of the organic remains of organisms, feces, and so on. 
D)  return energy lost to the ecosystem by other organisms.

Question 10

In a typical grassland community, which of the following is the primary consumer?

Accepted Answer

A)  hawk 
B)  snake 
C)  shrew 
D)  grasshopper 
E)  grass 
A)  hawk 
B)  snake 
C)  shrew 
D)  grasshopper 
E)  grass

Question 11

If the flow of energy in an arctic ecosystem goes through a simple food chain, perhaps involving humans, starting from phytoplankton to zooplankton to fish to seals to polar bears, then which of the following could be true?

Accepted Answer

A)  Polar bears can provide more food for humans than seals can. 
B)  The total biomass of the fish is lower than that of the seals. 
C)  Seal meat probably contains the highest concentrations of fat-soluble toxins. 
D)  Seal populations are larger than fish populations. 
E)  The fish can potentially provide more food for humans than the seal meat can. 
A)  Polar bears can provide more food for humans than seals can. 
B)  The total biomass of the fish is lower than that of the seals. 
C)  Seal meat probably contains the highest concentrations of fat-soluble toxins. 
D)  Seal populations are larger than fish populations. 
E)  The fish can potentially provide more food for humans than the seal meat can.

Question 12

In ecosystems, why is the term cycling used to describe material transfer, whereas the term flow is used for energy exchange?

Accepted Answer

A)  Materials are repeatedly used, but energy flows through and out of ecosystems. 
B)  Both material and energy are recycled and are then transferred to other ecosystems as in a flow. 
C)  Materials are cycled into ecosystems from other ecosystems, but energy constantly flows within the ecosystem. 
D)  Both material and energy flow in a never-ending stream within an ecosystem. 
E)  None of the choices is correct. 
A)  Materials are repeatedly used, but energy flows through and out of ecosystems. 
B)  Both material and energy are recycled and are then transferred to other ecosystems as in a flow. 
C)  Materials are cycled into ecosystems from other ecosystems, but energy constantly flows within the ecosystem. 
D)  Both material and energy flow in a never-ending stream within an ecosystem. 
E)  None of the choices is correct.

Question 13

Subtraction of which of the following will convert gross primary productivity into net primary productivity?

Accepted Answer

A)  the energy contained in the standing crop 
B)  the energy used by heterotrophs in respiration 
C)  the energy used by autotrophs in respiration 
D)  the energy fixed by photosynthesis 
E)  all solar energy 
A)  the energy contained in the standing crop 
B)  the energy used by heterotrophs in respiration 
C)  the energy used by autotrophs in respiration 
D)  the energy fixed by photosynthesis 
E)  all solar energy

Question 14

Which of these ecosystems accounts for the largest amount of Earth's net primary productivity?

Accepted Answer

A)  tundra 
B)  savanna 
C)  salt marsh 
D)  open ocean 
E)  tropical rain forest 
A)  tundra 
B)  savanna 
C)  salt marsh 
D)  open ocean 
E)  tropical rain forest

Question 15

Which of the following is a true statement regarding mineral nutrients in soils and their implication for primary productivity?

Accepted Answer

A)  Globally, phosphorous availability is most limiting to primary productivity. 
B)  Adding a nonlimiting nutrient will stimulate primary productivity. 
C)  Adding more of a limiting nutrient will increase primary productivity, indefinitely. 
D)  Phosphorous is sometimes unavailable to producers due to leaching. 
E)  Alkaline soils are more productive than acidic soils. 
A)  Globally, phosphorous availability is most limiting to primary productivity. 
B)  Adding a nonlimiting nutrient will stimulate primary productivity. 
C)  Adding more of a limiting nutrient will increase primary productivity, indefinitely. 
D)  Phosphorous is sometimes unavailable to producers due to leaching. 
E)  Alkaline soils are more productive than acidic soils.

Question 16

For most terrestrial ecosystems, pyramids composed of species abundances, biomass, and energy are similar in that they have a broad base and a narrow top. The primary reason for this pattern is that

Accepted Answer

A)  secondary consumers and top carnivores require less energy than producers. 
B)  at each step, energy is lost from the system because of the second law of thermodynamics. 
C)  as matter passes through ecosystems, some of it is lost to the environment. 
D)  biomagnification of toxic materials limits the secondary consumers and top carnivores. 
E)  top carnivores and secondary consumers have a more general diet than primary producers. 
A)  secondary consumers and top carnivores require less energy than producers. 
B)  at each step, energy is lost from the system because of the second law of thermodynamics. 
C)  as matter passes through ecosystems, some of it is lost to the environment. 
D)  biomagnification of toxic materials limits the secondary consumers and top carnivores. 
E)  top carnivores and secondary consumers have a more general diet than primary producers.

Question 17

Aquatic ecosystems are most likely to be limited by which of the following nutrients?

Accepted Answer

A)  nitrogen 
B)  carbon 
C)  potassium 
D)  iron 
E)  zinc 
A)  nitrogen 
B)  carbon 
C)  potassium 
D)  iron 
E)  zinc

Question 18

Which of the following statements is correct about biogeochemical cycling?

Accepted Answer

A)  The phosphorus cycle involves the recycling of atmospheric phosphorus. 
B)  The phosphorus cycle involves the weathering of rocks. 
C)  The carbon cycle is a localized cycle that primarily involves the burning of fossil fuels. 
D)  The carbon cycle has maintained a constant atmospheric concentration of CO2 for the past million years. 
E)  The nitrogen cycle involves movement of diatomic nitrogen between the biotic and abiotic components of the ecosystem. 
A)  The phosphorus cycle involves the recycling of atmospheric phosphorus. 
B)  The phosphorus cycle involves the weathering of rocks. 
C)  The carbon cycle is a localized cycle that primarily involves the burning of fossil fuels. 
D)  The carbon cycle has maintained a constant atmospheric concentration of CO2 for the past million years. 
E)  The nitrogen cycle involves movement of diatomic nitrogen between the biotic and abiotic components of the ecosystem.

Question 19

Which of the following relies upon existing biodiversity for the decontamination of polluted ecosystems?

Accepted Answer

A)  Some types of bacteria naturally convert toxins to less hazardous forms. 
B)  Sawdust from lumber mills can be used to soak up chemicals that have saturated natural ecosystems. 
C)  Species in contaminated areas may evolve into forms that can survive in contaminated soils. 
D)  After centuries of agricultural production, soils depleted of nitrogen can be replenished by promoting the growth of nitrogen-fixing organisms. 
A)  Some types of bacteria naturally convert toxins to less hazardous forms. 
B)  Sawdust from lumber mills can be used to soak up chemicals that have saturated natural ecosystems. 
C)  Species in contaminated areas may evolve into forms that can survive in contaminated soils. 
D)  After centuries of agricultural production, soils depleted of nitrogen can be replenished by promoting the growth of nitrogen-fixing organisms.

Question 20

Consider the food chain grass → grasshopper → mouse → snake → hawk. How much of the chemical energy fixed by photosynthesis of the grass (100%) is available to the hawk?

Accepted Answer

A)  0.01% 
B)  0.1% 
C)  1% 
D)  10% 
E)  60% 
A)  0.01% 
B)  0.1% 
C)  1% 
D)  10% 
E)  60%

Exam 42: Ecosystems and Energy

The Hubbard Brook watershed deforestation experiment yielded all of the following results except:

A cow's herbivorous diet indicates that it is a(n)

Which of the following ecosystems would likely have a larger net primary productivity/hectare, and why?

Which of the following lists of organisms is ranked in correct order from lowest to highest percent in production efficiency?

To recycle nutrients, an ecosystem must have, at a minimum,

Which of the following is an example of an ecosystem?

Which of these ecosystems has the lowest net primary production per square meter?

In the nitrogen cycle, the bacteria that replenish the atmosphere with N2 are

The major role of detritivores in ecosystems is to

In a typical grassland community, which of the following is the primary consumer?

If the flow of energy in an arctic ecosystem goes through a simple food chain, perhaps involving humans, starting from phytoplankton to zooplankton to fish to seals to polar bears, then which of the following could be true?

In ecosystems, why is the term cycling used to describe material transfer, whereas the term flow is used for energy exchange?

Subtraction of which of the following will convert gross primary productivity into net primary productivity?

Which of these ecosystems accounts for the largest amount of Earth's net primary productivity?

Which of the following is a true statement regarding mineral nutrients in soils and their implication for primary productivity?

For most terrestrial ecosystems, pyramids composed of species abundances, biomass, and energy are similar in that they have a broad base and a narrow top. The primary reason for this pattern is that

Aquatic ecosystems are most likely to be limited by which of the following nutrients?

Which of the following statements is correct about biogeochemical cycling?

Which of the following relies upon existing biodiversity for the decontamination of polluted ecosystems?

Consider the food chain grass → grasshopper → mouse → snake → hawk. How much of the chemical energy fixed by photosynthesis of the grass (100%) is available to the hawk?

Introduction: Evolution and the Foundations of Biology

The Chemical Context of Life

Carbon and the Molecular Diversity of Life

A Tour of the Cell

Membrane Transport and Cell Signaling

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

Gene Expression: From Gene to Protein

Regulation of Gene Expression

Development, Stem Cells, and Cancer

Viruses

Genomes and Their Evolution

Descent With Modification

Phylogeny

The Evolution of Populations

The Origin of Species

Broad Patterns of Evolution

Early Life and the Diversification of Prokaryotes

The Origin and Diversification of Eukaryotes

The Colonization of Land by Plants and Fungi

The Rise of Animal Diversity

Plant Structure and Growth

Resource Acquisition, Nutrition, and Transport in Vascular Plants

Reproduction and Domestication of Flowering Plants

Plant Responses to Internal and External Signals

Homeostasis and Endocrine Signaling

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Reproduction and Development

Neurons, Synapses, and Signaling

Nervous and Sensory Systems

Motor Mechanisms and Behavior

Population Ecology and the Distribution of Organisms

Species Interactions

Global Ecology and Conservation Biology

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