Photosynthetic organisms are unique to most ecosystems because they
A) synthesize organic compounds they obtain from decaying heterotrophs.
B) synthesize inorganic compounds from organic compounds.
C) use light energy to synthesize organic compounds from inorganic compounds.
D) use chemical energy to synthesize organic compounds.
E) convert light energy into matter.

use light energy to synthesize organic compounds from inorganic compounds.

A cow's herbivorous diet indicates that it is a(n)
A) primary consumer.
B) secondary consumer.
C) decomposer.
D) autotroph.
E) producer.

primary consumer.

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

producers and decomposers.

Which of the following terms encompasses all of the others?
A) heterotrophs
B) herbivores
C) carnivores
D) primary consumers
E) secondary consumers

heterotrophs

Which of the following is an example of an ecosystem?
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

all of the organisms and their physical environment in a tropical rain forest

If the sun were to suddenly stop providing energy to Earth, most ecosystems would vanish.
Which of the following ecosystems would likely survive the longest after this hypothetical
disaster?
A) tropical rain forest
B) tundra
C) deep-sea vent community
D) grassland
E) desert

deep-sea vent community

Which of the following is true of detritivores?
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, whereas others are heterotrophic.

They convert organic materials from all trophic levels to inorganic compounds usable by
primary producers.

The major role of detritivores in ecosystems is to
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.

recycle chemical nutrients to a form capable of being used by autotrophs.

In a typical grassland community, which of the following is the primary consumer?
A) hawk
B) snake
C) shrew
D) grasshopper
E) grass

grasshopper

Which of the following statements is true?
A) An ecosystem's trophic structure determines the rate at which energy cycles within the
system.
B) At any point in time, it is impossible for consumers to outnumber producers in an ecosystem.
C) Chemoautotrophic prokaryotes near deep-sea vents are primary producers.
D) There has been a well-documented increase in atmospheric nitrogen over the past several
decades.
E) The reservoir of ecosystem phosphorous is the atmosphere.

Chemoautotrophic prokaryotes near deep-sea vents are primary producers.

Approximately 1% of the solar radiation that strikes a plant is converted into the chemical
bond energy of sugars. Why is this amount so low?
A) Approximately 99% of the solar radiation is converted to heat energy.
B) Only 1% of the wavelengths of visible light is absorbed by photosynthetic pigments.
C) Most solar energy strikes water and land surfaces.
D) Approximately 99% of the solar radiation is reflected.
E) Only the green wavelengths are absorbed by plants for photosynthesis.

Only 1% of the wavelengths of visible light is absorbed by photosynthetic pigments.

What percentage of solar radiation striking a plant is converted into chemical energy?
A) 1%
B) 10%
C) 25%
D) 50%
E) 100%

1%

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

the energy used by autotrophs in respiration

Which of these ecosystems accounts for the largest amount of Earth's net primary
productivity?
A) tundra
B) savanna
C) salt marsh
D) open ocean
E) tropical rain forest

open ocean

Which of these ecosystems has the highest net primary productivity per square meter
annually?
A) savanna
B) open ocean
C) boreal forest
D) tropical rain forest
E) temperate forest

tropical rain forest

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

Phosphorous is sometimes unavailable to producers due to leaching.

The total biomass of photosynthetic autotrophs present in an ecosystem is known as
A) gross primary productivity.
B) standing crop.
C) net primary productivity.
D) secondary productivity.
E) trophic efficiency.

standing crop.

How is it that the open ocean produces the highest net primary productivity of Earth's
ecosystems, yet net primary productivity per square meter is relatively low?
A) Oceans contain greater concentrations of nutrients compared to other ecosystems.
B) Oceans receive a lesser amount of solar energy per unit area.
C) Oceans have the largest area of all the ecosystems on Earth.
D) Ocean ecosystems have less species diversity.
E) Oceanic producers are generally much smaller than oceanic consumers.

Oceans have the largest area of all the ecosystems on Earth.

Why is net primary production (NPP) a more useful measurement to an ecosystem ecologist
than gross primary production (GPP)?
A) NPP can be expressed in energy/unit of area/unit of time.
B) NPP can be expressed in terms of carbon fixed by photosynthesis for an entire ecosystem.
C) NPP represents the stored chemical energy that will be available to consumers in the
ecosystem.
D) NPP is the same as the standing crop.
E) NPP shows the rate at which the standing crop is utilized by consumers.

NPP represents the stored chemical energy that will be available to consumers in the
ecosystem.

How is net ecosystem production (NEP) typically estimated in ecosystems?
A) the ratio of producers to consumers
B) the amount of heat energy released by the ecosystem
C) the net flux of CO2 or O2 in or out of an ecosystem
D) the rate of decomposition by detritivores
E) the annual total of incoming solar radiation per unit of area

the net flux of CO2 or O2 in or out of an ecosystem

Aquatic primary productivity is most limited by which of the following?
A) light and nutrient availability
B) predation by primary consumers
C) increased pressure with depth
D) pollution
E) temperature

light and nutrient availability

Aquatic ecosystems are most likely to be limited by which of the following nutrients?
A) nitrogen
B) carbon
C) potassium
D) iron
E) zinc

nitrogen

What is the primary limiting factor for aquatic productivity?
A) pressure
B) lack of nutrients
C) light availability
D) herbivores
E) competition

lack of nutrients

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

tropical rain forest because of the high species diversity

How is it that satellites can detect differences in primary productivity on Earth?
A) Photosynthetic organisms absorb more visible light in the 350-750 wavelengths.
B) Satellite instruments can detect reflectance patterns of the photosynthetic organisms of
different ecosystems.
C) Sensitive satellite instruments can measure the amount of NADPH produced in the
summative light reactions of different ecosystems.
D) Satellites detect differences by comparing the wavelengths of light captured and reflected by
photoautotrophs to the amount of light reaching different ecosystems.
E) Satellites detect differences by measuring the amount of water vapor emitted by transpiring
producers.

Satellites detect differences by comparing the wavelengths of light captured and reflected by
photoautotrophs to the amount of light reaching different ecosystems.

Which of the following lists of organisms is ranked in correct order from lowest to highest
percent in production efficiency?
A) mammals, fish, insects
B) insects, fish, mammals
C) fish, insects, mammals
D) insects, mammals, fish
E) mammals, insects, fish

mammals, fish, insects