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

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

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.

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.

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

detritivores

Photosynthetic organisms are called _____.
A)autotrophs
B)heterotrophs
C)herbivores
D)carnivores
E)consumers

autotrophs

When you eat an apple, you are a _____.
A)primary consumer
B)carnivore
C)primary producer
D)secondary consumer
E)detritivore

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

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

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

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

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.

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

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.

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.

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.

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

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.

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

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

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

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.

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

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.

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.

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

respiration

Bacteria are especially important in making _____ available to plants.
A)water
B)nitrogen
C)carbon
D)phosphorus
E)energy

nitrogen

The direct product of nitrogen fixation is _____.
A)NH4+
B)NO2-
C)NO3-
D)NH3
E)N2

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.

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

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.

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

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

biological augmentation