Chapter 55 Bio Final

The energy for nearly every organism in nearly every ecosystem ultimately comes from _____.
a. minerals in the soil
b. the sun
c. heat from Earth
d. respiration
e. decomposition

b. the sun

On a global scale, energy _____ ecosystems whereas chemical elements _____ ecosystems.
a. is biologically magnified in … are recycled in
b. is dissipated in … flow through
c. flows through … are recycled in
d. is continuously supplied to … are continuously removed from
e. is recycled in … flow through

c. flows through … are recycled in

Consider this segment of a food web: Snails and grasshoppers eat pepper plants; spiders eat grasshoppers; shrews eat snails and spiders; owls eat shrews. The shrew occupies the trophic level(s) of _____.
a. primary consumer only
b. secondary consumer only
c. tertiary consumer only
d. primary and secondary consumers
e. secondary and tertiary consumers

e. secondary and tertiary consumers

Which of the following equations is correct?
a. NPP = GPP − R
b. R = NPP + GPP
c. GPP = NPP − R
d. NPP = GPP + R
e. NPP = GPP/R

a. NPP = GPP − R

The relationship between biomass and primary productivity is that _____.
a. biomass is the rate of primary productivity
b. biomass is the inverse of primary productivity
c. biomass is the natural log of primary productivity
d. primary productivity is the inverse of biomass
e. primary productivity is the rate at which biomass is produced

e. primary productivity is the rate at which biomass is produced

Why is a diagram of energy flow from trophic level to trophic level shaped like a pyramid?
a. Organisms at each level store most of the energy and pass little on.
b. There are more producers than primary consumers, and so on.
c. Organisms eventually die.
d. Most energy at each level is lost, leaving little for the next.
e. Secondary consumers are larger than primary consumers, and so on.

d. Most energy at each level is lost, leaving little for the next.

Biogeochemical cycles are crucial to ecosystem function because _____.
a. they keep the planet warm enough for living things to survive
b. nutrients and other life-sustaining molecules are in limited supply and must be continually recycled
c. energy flows through ecosystems in one direction only and is eventually dissipated as heat
d. they remove poisons and keep them locked up in "sinks"
e. they prevent catastrophic extinctions

b. nutrients and other life-sustaining molecules are in limited supply and must be continually recycled

An ecosystem is unlikely to be limited by the supply of _____ because it is obtained from the air.
a. water
b. carbon
c. phosphorus
d. calcium
e. nitrogen

b. carbon

In contrast to bioremediation, which is a strategy for _____, biological augmentation _____ a degraded ecosystem.
a. using organisms to add essential materials … removes harmful substances from
b. replacing extirpated species… removes man-created pollutants and toxins from
c. eradicating a crippling disease in a keystone species…involves planting fruit- and grain-bearing crops to provide more forage in
d. removing harmful substances…uses organisms to add essential materials to
e. adding new species to control problem species…adds fertilizer to nutrient-poor soils in

d. removing harmful substances…uses organisms to add essential materials to

The producers in aquatic ecosystems include organisms in which of the following groups?
a. cyanobacteria
b. algae
c. plants
d. photoautotrophs
e. All of the above are correct.

e. All of the above are correct.

Ecosystem

sum of all the organisms living in a given area and the abiotic factors with which they interact

Law of conservation of mass

matter cannot be created or destroyed

Primary producers

-Autotrophs -Photosynthetic organisms that use light energy to synthesize sugars and other organic compounds

Primary Consumers

herbivores

Secondary Consumers

Carnivores

Tertiary consumers

carnivores that consume other carnivores

Detritivores

-Heterotrophs -decomposers -get energy from detritus

Detritus

nonliving organic material

Primary production

the amount of light energy converted by chemical energy by autotrophs during a given time period

Gross Primary Production (GPP)

total primary production in an ecosystem; amount of energy from light converted to chemical energy of organic molecules per unit of time

Net Primary Production

equal to gross primary production minus the energy used by the primary producers for their "autotrophic respiration" NPP=GPP-Ra

Standing Crop

total biomass of photosynthetic autotrophs present

Net Ecosystem Production

measure of the total biomass accumulation during a given period of time NEP=GPP-Rt

Limiting nutrient

element that must be added for production to increase

Eutrophication

reducing the oxygen concentration and clarity of water by cyanobacteria and algae causes fish deaths

Secondary production

amount of chemical energy in consumers’ food that is converted to their own new biomass during a given period

Production efficiency

percentage of energy stored in assimilated food that is not used for respiration

Trophic effciency

percentage of production transferred from one trophic level to the next

Turnover time

small standing crop compared to production turnover time= standing crop/ production

Biogeochemical cycles

-nutrient cycles that involve both biotic and abiotic components -Global and local

Carbon Reservoirs

fossil fuels, soils, sediments of aquatic ecosystems, oceans, plant and animal biomass, and atmosphere

Nitrogen Reservoirs

atmosphere, soils and sediments of lakes, rivers and oceans, surface of water and groundwater, and biomass of living organisms

Phosphorus Reservoirs

sedimentary rocks, soil, oceans, organisms

Bioremediation

using organisms to detoxify polluted ecosystems

Biological augmentation

uses organisms to add essential materials to a degraded ecosystem

Which of the following organisms is incorrectly paired with its trophic level?
a. grasshopper-primary consumer
b. cyanobacterium-primary producer
c. zooplankton-primary producer
d. eagle-tertiary consumer
e. fungus-detritivore

c. zooplankton-primary producer

Which of these ecosystems has the lowest net primary production per square meter?
a. a grassland
b. a tropical rain forest
c. a salt marsh
d. a coral reef
e. an open ocean

e. an open ocean

The discipline that applies ecological principles to returning degraded ecosystems to a more natural state is known as
a. population viability analysis.
b. conservation ecology.
c. resource conservation.
d. landscape ecology.
e. restoration ecology.

e. restoration ecology.

Nitrifying bacteria participate in the nitrogen cycle mainly by
a. releasing ammonium from organic compounds, thus returning it to the soil.
b. converting ammonium to nitrate, which plants absorb.
c. incorporating nitrogen into amino acids and organic compounds.
d. converting ammonia to nitrogen gas, which returns to the atmosphere.
e. converting nitrogen gas to ammonia.

b. converting ammonium to nitrate, which plants absorb.

Which of the following has the greatest effect on the rate of chemical cycling in an ecosystem?
a. the location of the nutrient reservoirs in the ecosystem
b. the trophic efficiency of the ecosystem
c. the ecosystem’s rate of primary production
d. the production efficiency of the ecosystem’s consumers
e. the rate of decomposition in the ecosystem

e. the rate of decomposition in the ecosystem

The Hubbard Brook watershed deforestation experiment yielded all of the following results except:
a. The flow of minerals out of a natural watershed was offset by minerals flowing in.
b. Calcium levels remained high in the soil of deforested areas.
c. Deforestation increased water runoff.
d. The nitrate concentration in waters draining the deforested area became dangerously high.
e. Most minerals were recycled within a forest ecosystem.

b. Calcium levels remained high in the soil of deforested areas.

Which of the following would be considered an example of bioremediation?
a. adding nitrogen-fixing microorganisms to a degraded ecosystem to increase nitrogen availability
b. using a bulldozer to regrade a strip mine
c. adding seeds of a chromium-accumulating plant to soil contaminated by chromium
d. dredging a river bottom to remove contaminated sediments
e. reconfiguring the channel of a river

a. adding nitrogen-fixing microorganisms to a degraded ecosystem to increase nitrogen availability

If you applied a fungicide to a cornfield, what would you expect to happen to the rate of decomposition and net ecosystem production (NEP)?
a. Decomposition rate would decrease and NEP would increase.
b. Neither would change.
c. Decomposition rate would increase and NEP would decrease.
d. Both decomposition rate and NEP would decrease.
e. Both decomposition rate and NEP would increase.

a. Decomposition rate would decrease and NEP would increase.

Which of the following is an ecosystem?
a. all of the angelfish in your aquarium
b. all of the organisms living in your aquarium
c. all of the angelfish on the planet
d. all of the organisms living in your aquarium and the abiotic factors with which they interact
e. the water, temperature, rocks, and other abiotic components of the aquarium

d. all of the organisms living in your aquarium and the abiotic factors with which they interact

The biggest difference between the flow of energy and the flow of chemical nutrients in an ecosystem is that _____.
a. the amount of energy is much greater than the amount of nutrients
b. energy is recycled, but nutrients are not
c. organisms always need nutrients, but they don’t always need energy
d. nutrients are recycled, but energy is not
e. organisms always need energy, but they don’t always need nutrients

d. nutrients are recycled, but energy is not

In an ecosystem, all incoming energy will eventually be _____.
a. transferred from one trophic level to the next
b. transferred to the decomposers
c. dissipated into space as heat
d. used in photosynthesis
e. None of the listed responses is correct.

c. dissipated into space as heat

Based on the law of conservation of energy, ecosystem ecologists can make which of the following assertions?
a. The total amount of energy stored in organic molecules plus the amounts reflected and dissipated as heat must equal the total solar energy intercepted by the Earth.
b. Photosynthetic organisms can convert approximately 1% of the solar energy they receive into organic molecules.
c. Approximately 10% of energy is transferred from one trophic level to the next.
d. Elements are not lost on a global scale.
e. All of the listed responses are correct

a. The total amount of energy stored in organic molecules plus the amounts reflected and dissipated as heat must equal the total solar energy intercepted by the Earth.

Which of the following is a primary producer?
a. detritivores
b. shrimp
c. poison ivy
d. lions
e. humans

c. poison ivy

Photosynthetic organisms are called _____.
a. autotrophs
b. heterotrophs
c. herbivores
d. carnivores
e. consumers

a. autotrophs

When you eat an apple, you are a _____.
a. primary consumer
b. carnivore
c. primary producer
d. secondary consumer
e. detritivore

a. primary consumer

The main decomposers in an ecosystem are _____.
a. plants and animals
b. prokaryotes and animals
c. fungi and prokaryotes
d. prokaryotes and plants
e. plants and fungi

c. fungi and prokaryotes

Most of the sunlight that reaches Earth _____.
a. is used by plants for photosynthesis
b. is not captured for use by living things
c. is continually recycled by ecosystems
d. is trapped by greenhouse gases
e. is used by algae for photosynthesis

b. is not captured for use by living things

The rate at which producers convert solar energy to the chemical energy of organic compounds, minus the energy used during respiration, is called _____.
a. biomass
b. standing crop
c. net ecosystem production
d. net primary production
e. gross primary production

d. net primary production

In a particular ecosystem, what value do you have if you subtract the total respiration of all organisms in that system from the amount of light energy converted to chemical energy by photosynthesizers in the ecosystem?
a. standing crop
b. net ecosystem production
c. gross primary production
d. net primary production
e. actual evapotranspiration

b. net ecosystem production

A study of metabolic rates in a terrestrial community showed that the energy released by respiration exceeded the energy captured in photosynthesis. Which of the following situations is most likely?
a. Community biomass is increasing.
b. Community biomass is decreasing.
c. The second law of thermodynamics (in a closed system, there is a general tendency toward disorder) is not in effect.
d. The first law of thermodynamics (energy is conserved) in not in effect.
e. None of the listed responses is correct.

b. Community biomass is decreasing.

What are the major factors that control primary production in terrestrial ecosystems?
a. light and nutrients
b. light and moisture
c. temperature and moisture
d. temperature and nutrients
e. temperature and light

c. temperature and moisture

How do iron levels affect phytoplankton populations in a marine ecosystem?
a. Without iron, eukaryotic phytoplankton populations fall because they cannot convert atmospheric N2 to nitrogenous minerals.
b. In the presence of too much iron, eukaryotic phytoplankton populations fall because they cannot convert atmospheric N2 to nitrogenous minerals.
c. Iron stimulates the growth of cyanobacteria, which convert atmospheric N2 to nitrogenous minerals, stimulating the growth of phytoplankton.
d. Iron halts the growth of cyanobacteria, which convert atmospheric N2 to nitrogenous minerals; therefore, phytoplankton populations are limited.
e. Nitrogen and phosphorus are the only known limiting nutrients in marine ecosystems.

c. Iron stimulates the growth of cyanobacteria, which convert atmospheric N2 to nitrogenous minerals, stimulating the growth of phytoplankton.

Eutrophication in lakes is frequently the direct result of _____.
a. a diminished supply of nitrates and phosphates
b. industrial poisons
c. nutrient enrichment such as nitrate and phosphate runoffs from land
d. an increase in primary consumers
e. None of the listed responses is correct.

c. nutrient enrichment such as nitrate and phosphate runoffs from land

The amount of chemical energy in a consumer’s food that is converted to its own new biomass over a period of time is called _____.
a. primary production
b. secondary production
c. production efficiency
d. net ecosystem production
e. This question cannot be answered without knowing at which trophic level the organism feeds.

b. secondary production

In the transition from each trophic level of the food chain to the next trophic level, there is about a _____.
a. 90% gain of energy
b. 2% gain of energy
c. 90% loss of energy
d. 2% loss of energy
e. 5% loss of energy

c. 90% loss of energy

Which of the following best describes the base of a pyramid of net production?
a. Its size depends on the energy available from detritivores.
b. It contains the energy left after the producers have died.
c. It represents the energy available to secondary consumers.
d. It contains the energy captured by photosynthesis.
e. It receives energy from the primary, secondary, and tertiary consumers.

d. It contains the energy captured by photosynthesis.

In general, the biomass in an ecosystem will be greatest at the trophic level comprising _____.
a. producers
b. herbivores
c. primary consumers
d. carnivores
e. secondary consumers

a. producers

In ecosystems, organisms at the highest trophic levels usually contain less collective biomass than the organisms at lower trophic levels because _____.
a. organisms are inefficient at converting the energy they consume into biomass
b. biomass shrinks as it rises
c. top-level predators use so much energy to catch their food
d. producers (for example, plants) tend to be heavier than consumers (for example, birds)
e. most of the solar energy hitting Earth is reflected back into space

a. organisms are inefficient at converting the energy they consume into biomass

What is the main abiotic reservoir for elements involved in local biogeochemical cycles, such as calcium and phosphorus?
a. oceans
b. rivers
c. soil
d. wind
e. the atmosphere

c. soil

Which of the following statements is correct?
a. Over land, evaporation exceeds transpiration and precipitation.
b. Over land, evaporation and transpiration exceed precipitation.
c. Over oceans, transpiration exceeds precipitation.
d. Over oceans, evaporation exceeds precipitation.
e. Most of Earth’s water can be found in living systems.

d. Over oceans, evaporation exceeds precipitation.

The global hydrologic cycle supports a net flow of atmospheric water vapor _____.
a. from the oceans to land
b. from land to the oceans
c. from polar to tropical regions
d. from tropical to polar regions
e. from unforested to forested biomes

a. from the oceans to land

Local conditions such as heavy rainfall or the removal of plants may limit the amount of nitrogen, phosphorus, or calcium available to a particular ecosystem, but the amount of carbon available to the system is seldom a problem. Why? a. Organisms do not need very much carbon.
b. Plants can make their own carbon using water and sunlight.
c. Plants are much better at absorbing carbon from the soil.
d. Many nutrients come from the soil, but carbon comes from the air.
e. Symbiotic bacteria help plants capture carbon.

d. Many nutrients come from the soil, but carbon comes from the air.

Which of the following is a key part of the carbon cycle?
a. return of CO2 to the atmosphere by burning fossil fuels
b. assimilation of atmospheric CO2 by plant photosynthesis
c. return of CO2 to the atmosphere by animal and plant respiration
d. breakdown by decomposers of carbon-containing dead plants and animals
e. All of the listed responses are correct.

e. All of the listed responses are correct.

By which process is carbon dioxide released from plants back to the atmosphere?
a. photosynthesis
b. respiration
c. ammonification
d. phosphorylation
e. evaporation

b. respiration

Bacteria are especially important in making _____ available to plants.
a. water
b. nitrogen
c. carbon
d. phosphorus
e. energy

b. nitrogen

The direct product of nitrogen fixation is _____.
a. NH4+
b. NO2-
c. NO3-
d. NH3
e. N2

d. NH3

Which of the following is true of the nitrogen cycle?
a. Bacteria are not involved in the process.
b. Plants can take in and use atmospheric nitrogen through their leaves.
c. Some animals can use inorganic forms of nitrogen such as ammonium.
d. When plants and animals die, the nitrogen within their bodies becomes unavailable.
e. Nitrite is converted to nitrate (NO3-) by nitrifying bacteria.

e. Nitrite is converted to nitrate (NO3-) by nitrifying bacteria.

The phosphorus cycle lacks a(n) _____ component.
a. atmospheric
b. organic
c. mineral
d. aquatic
e. organic and gaseous

a. atmospheric

When researchers at Hubbard Brook Experimental Forest cut down trees and measured subsequent mineral levels in the soil, they found that _____.
a. the mineral levels were unaffected as long as the tree remains were not removed
b. primary production was not affected as long as Ca2+ was added to the soil
c. the forest was able to grow back before mineral levels changed significantly
d. the amount of nutrients leaving an intact forest ecosystem is controlled by the plants
e. None of the listed responses is correct.

d. the amount of nutrients leaving an intact forest ecosystem is controlled by the plants

_____ is the science of facilitating the return of a degraded ecosystem to a more natural condition.
a. Bioremediation
b. Biological restoration
c. Biological augmentation
d. Restoration ecology
e. Biophilia

d. Restoration ecology

The use of organisms to add essential materials to degraded systems defines _____.
a. biophilia
b. restoration ecology
c. bioremediation
d. biological augmentation
e. landscape management

d. biological augmentation

Autotrophs

capture sunlight or chemical energy

heterotrophs

extract energy from other organisms or organic wastes

biological magnification

A nondegradable or slowly degradable substance becomes more and more concentrated in the tissues of organisms at higher trophic levels of a food web

biosphere

The sum of all places in which life forms can be found.

Greenhouse effect

Greenhouse gases impede the escape of heat from Earth’s surface.

Global warming

Long-term increase in the temperature of Earth’s lower atmosphere.