Question 1

Which of the following has the greatest effect on the rate of chemical cycling in an ecosystem?

Accepted Answer

A) the ecosystem's rate of primary production 
B) the production efficiency of the ecosystem's consumers 
C) the rate of decomposition in the ecosystem 
D) the trophic efficiency of the ecosystem 
E) the location of the nutrient reservoirs in the ecosystem 
A) the ecosystem's rate of primary production 
B) the production efficiency of the ecosystem's consumers 
C) the rate of decomposition in the ecosystem 
D) the trophic efficiency of the ecosystem 
E) the location of the nutrient reservoirs in the ecosystem

Question 2

Nitrogen is available to plants only in the form of

Accepted Answer

A) N₂ in the atmosphere. 
B) nitrite ions in the soil. 
C) uric acid from animal excretions. 
D) amino acids from decomposing plant and animal proteins. 
E) nitrate ions in the soil. 
A) N₂ in the atmosphere. 
B) nitrite ions in the soil. 
C) uric acid from animal excretions. 
D) amino acids from decomposing plant and animal proteins. 
E) nitrate ions in the soil.

Question 3

Use the following food web to answer the questions below.
   
Food web for a particular terrestrial ecosystem (arrows represent energy flow and letters represent species)
-Examine this food web for a particular terrestrial ecosystem. Species C is toxic to predators. Which species is most likely to benefit from being a mimic of C?

Accepted Answer

A) A 
B) B 
C) C 
D) D 
E) E 
A) A 
B) B 
C) C 
D) D 
E) E

Question 4

When levels of CO₂ are experimentally increased in a typical grassland community, C₃ plants generally respond with a greater increase in productivity than C₄ plants. This is because

Accepted Answer

A) C₃ plants are more efficient in their use of CO₂. 
B) C₃ plants are able to obtain the same amount of CO₂ by keeping their stomata open for shorter periods of time. 
C) C₄ plants don't use CO₂ as their source of carbon. 
D) C₃ plants are more limited by CO₂ availability because they lack mechanisms to prevent transpirational water loss. 
E) C₃ plants have special adaptations for CO₂ uptake, such as larger stomata. 
A) C₃ plants are more efficient in their use of CO₂. 
B) C₃ plants are able to obtain the same amount of CO₂ by keeping their stomata open for shorter periods of time. 
C) C₄ plants don't use CO₂ as their source of carbon. 
D) C₃ plants are more limited by CO₂ availability because they lack mechanisms to prevent transpirational water loss. 
E) C₃ plants have special adaptations for CO₂ uptake, such as larger stomata.

Question 5

Which of the following would be considered an example of bioremediation?

Accepted Answer

A) adding nitrogen-fixing microorganisms to a degraded ecosystem to increase nitrogen availability 
B) using a bulldozer to regrade a strip mine 
C) dredging a river bottom to remove contaminated sediments 
D) reconfiguring the channel of a river 
E) adding seeds of a chromium-accumulating plant to soil contaminated by chromium 
A) adding nitrogen-fixing microorganisms to a degraded ecosystem to increase nitrogen availability 
B) using a bulldozer to regrade a strip mine 
C) dredging a river bottom to remove contaminated sediments 
D) reconfiguring the channel of a river 
E) adding seeds of a chromium-accumulating plant to soil contaminated by chromium

Question 6

The amount of chemical energy in consumers' food that is converted to their own new biomass during a given time period is known as which of the following?

Accepted Answer

A) biomass 
B) standing crop 
C) biomagnification 
D) primary production 
E) secondary production 
A) biomass 
B) standing crop 
C) biomagnification 
D) primary production 
E) secondary production

Question 7

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 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

Trophic efficiency is

Accepted Answer

A) the ratio of net secondary production to assimilation of primary production. 
B) the percentage of production transferred from one trophic level to the next. 
C) a measure of how nutrients are cycled from one trophic level to the next. 
D) usually greater than production efficiencies. 
E) about 90% in most ecosystems. 
A) the ratio of net secondary production to assimilation of primary production. 
B) the percentage of production transferred from one trophic level to the next. 
C) a measure of how nutrients are cycled from one trophic level to the next. 
D) usually greater than production efficiencies. 
E) about 90% in most ecosystems.

Question 10

Which of the following locations is the reservoir for carbon for the carbon cycle?

Accepted Answer

A) atmosphere 
B) sediments and sedimentary rocks 
C) fossilized plant and animal remains (coal, oil, and natural gas) 
D) plant and animal biomass 
E) all of the above 
A) atmosphere 
B) sediments and sedimentary rocks 
C) fossilized plant and animal remains (coal, oil, and natural gas) 
D) plant and animal biomass 
E) all of the above

Question 11

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 12

Two key strategies in biological restoration include

Accepted Answer

A) reversing the damage, adding fertilizer. 
B) removing dams, increasing water flow. 
C) adding soil, planting trees. 
D) bioremediation, biological augmentation. 
E) removing toxic soil, introducing fungi. 
A) reversing the damage, adding fertilizer. 
B) removing dams, increasing water flow. 
C) adding soil, planting trees. 
D) bioremediation, biological augmentation. 
E) removing toxic soil, introducing fungi.

Question 13

Which of the following properly links the nutrient to its reservoir?

Accepted Answer

A) nitrogen-ionic nitrogen in the soil 
B) water-atmospheric water vapour 
C) carbon-dissolved CO₂ in aquatic ecosystems 
D) phosphorous-sedimentary rocks 
E) All of the options are correct. 
A) nitrogen-ionic nitrogen in the soil 
B) water-atmospheric water vapour 
C) carbon-dissolved CO₂ in aquatic ecosystems 
D) phosphorous-sedimentary rocks 
E) All of the options are correct.

Question 14

Suppose you are studying the nitrogen cycling in a pond ecosystem over the course of a month. While you are collecting data, a flock of 100 Canada geese lands and spends the night during a fall migration. What could you do to eliminate error in your study as a result of this event?

Accepted Answer

A) Find out how much nitrogen is consumed in plant material by a Canada goose over about a 12-hour period, multiply this number by 100, and add that amount to the total nitrogen in the ecosystem. 
B) Find out how much nitrogen is eliminated by a Canada goose over about a 12-hour period, multiply this number by 100, and subtract that amount from the total nitrogen in the ecosystem. 
C) Find out how much nitrogen is consumed and eliminated by a Canada goose over about a 12-hour period and multiply this number by 100; enter this +/- value into the nitrogen budget of the ecosystem. 
D) Do nothing. The Canada geese visitation to the lake would have negligible impact on the nitrogen budget of the pond. 
E) Put a net over the pond so that no more migrating flocks can land on the pond and alter the nitrogen balance of the pond. 
A) Find out how much nitrogen is consumed in plant material by a Canada goose over about a 12-hour period, multiply this number by 100, and add that amount to the total nitrogen in the ecosystem. 
B) Find out how much nitrogen is eliminated by a Canada goose over about a 12-hour period, multiply this number by 100, and subtract that amount from the total nitrogen in the ecosystem. 
C) Find out how much nitrogen is consumed and eliminated by a Canada goose over about a 12-hour period and multiply this number by 100; enter this +/- value into the nitrogen budget of the ecosystem. 
D) Do nothing. The Canada geese visitation to the lake would have negligible impact on the nitrogen budget of the pond. 
E) Put a net over the pond so that no more migrating flocks can land on the pond and alter the nitrogen balance of the pond.

Question 15

Nitrifying bacteria participate in the nitrogen cycle mainly by

Accepted Answer

A) converting nitrogen gas to ammonia. 
B) releasing ammonium from organic compounds, thus returning it to the soil. 
C) converting ammonia to nitrogen gas, which returns to the atmosphere. 
D) converting ammonium to nitrate, which plants absorb. 
E) incorporating nitrogen into amino acids and organic compounds. 
A) converting nitrogen gas to ammonia. 
B) releasing ammonium from organic compounds, thus returning it to the soil. 
C) converting ammonia to nitrogen gas, which returns to the atmosphere. 
D) converting ammonium to nitrate, which plants absorb. 
E) incorporating nitrogen into amino acids and organic compounds.

Question 16

Which of the following is true of detrivores?

Accepted Answer

A) They recycle chemical elements directly back to primary consumers. 
B) They synthesize organic molecules that are used by primary producers. 
C) They convert organic materials from all trophic levels to inorganic compounds usable by primary producers. 
D) They secrete enzymes that convert the organic molecules of detritus into CO₂ and H₂O. 
E) Some species are autotrophic, while others are heterotrophic. 
A) They recycle chemical elements directly back to primary consumers. 
B) They synthesize organic molecules that are used by primary producers. 
C) They convert organic materials from all trophic levels to inorganic compounds usable by primary producers. 
D) They secrete enzymes that convert the organic molecules of detritus into CO₂ and H₂O. 
E) Some species are autotrophic, while others are heterotrophic.

Question 17

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 18

Use the following food web to answer the questions below.
   
Food web for a particular terrestrial ecosystem (arrows represent energy flow and letters represent species)
-Examine this food web for a particular terrestrial ecosystem. Which pair of species could be omnivores?

Accepted Answer

A) A and B 
B) A and D 
C) B and C 
D) C and D 
E) C and E 
A) A and B 
B) A and D 
C) B and C 
D) C and D 
E) C and E

Question 19

Which of the following is primarily responsible for limiting the number of trophic levels in most ecosystems?

Accepted Answer

A) Many primary and higher-order consumers are opportunistic feeders. 
B) Decomposers compete with higher-order consumers for nutrients and energy. 
C) Nutrient cycles involve both abiotic and biotic components of ecosystems. 
D) Nutrient cycling rates tend to be limited by decomposition. 
E) Energy transfer between tropic levels is in almost all cases less than 20% efficient. 
A) Many primary and higher-order consumers are opportunistic feeders. 
B) Decomposers compete with higher-order consumers for nutrients and energy. 
C) Nutrient cycles involve both abiotic and biotic components of ecosystems. 
D) Nutrient cycling rates tend to be limited by decomposition. 
E) Energy transfer between tropic levels is in almost all cases less than 20% efficient.

Question 20

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) grassland because of the small standing crop biomass that results from consumption by herbivores and rapid decomposition 
C) tropical rain forest because of the massive standing crop biomass and 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) grassland because of the small standing crop biomass that results from consumption by herbivores and rapid decomposition 
C) tropical rain forest because of the massive standing crop biomass and 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

Exam 55: Ecosystems and Restoration Ecology

Which of the following has the greatest effect on the rate of chemical cycling in an ecosystem?

Nitrogen is available to plants only in the form of

When levels of CO₂ are experimentally increased in a typical grassland community, C₃ plants generally respond with a greater increase in productivity than C₄ plants. This is because

Which of the following would be considered an example of bioremediation?

The amount of chemical energy in consumers' food that is converted to their own new biomass during a given time period is known as which of the following?

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

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

Trophic efficiency is

Which of the following locations is the reservoir for carbon for the carbon cycle?

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

Two key strategies in biological restoration include

Which of the following properly links the nutrient to its reservoir?

Suppose you are studying the nitrogen cycling in a pond ecosystem over the course of a month. While you are collecting data, a flock of 100 Canada geese lands and spends the night during a fall migration. What could you do to eliminate error in your study as a result of this event?

Nitrifying bacteria participate in the nitrogen cycle mainly by

Which of the following is true of detrivores?

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?

Use the following food web to answer the questions below. Food web for a particular terrestrial ecosystem (arrows represent energy flow and letters represent species) -Examine this food web for a particular terrestrial ecosystem. Which pair of species could be omnivores?

Which of the following is primarily responsible for limiting the number of trophic levels in most ecosystems?

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

Introduction: Evolution and Themes of Biology

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Regulation of Gene Expression

Viruses

Dna Tools and Biotechnology

Genomes and Their Evolution

Descent With Modification: a Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity Ii: the Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Plant Structure, Growth, and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signalling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behaviour

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Conservation Biology and Global Change

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