Download Which statement best describes the relationship between free

2.3 D: Free Energy of Ecosystems Quiz
1.
Which statement best describes the relationship between free energy and the trophic levels of an
ecosystem?
(A) Since approximately 10% of the free energy available at one trophic level is available to the
organisms at the next trophic level, the number of organisms at each trophic level is
approximately 10% of the number at the previous level.
(B) Since all ecosystems receive the same amount of free energy from the sun, all the
organisms at the same trophic level receive about the same amount of free energy, which
is approximately 10% of the free energy available to the organisms at the previous trophic
level.
(C) The amount of free energy that is transferred to the environment as thermal energy at each
trophic level is approximately 10%, which means that the total number of organisms that
are supported at each successive trophic level is less because of several factors, including
a reduced biomass and a decreased reproductive rate.
(D) The amount of free energy available to the organisms at a trophic level is approximately
10% of the free energy available at the previous trophic level, but the actual amount of free
energy transferred between trophic levels depends on many factors, including the
organisms’ energy requirements and environmental conditions.
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2.3 D: Free Energy of Ecosystems Quiz
2.
A small island is hit by a massive hurricane. The only two species that survive the hurricane are
frogs and mosquitoes. Frogs feed on mosquitoes and mosquitoes feed on frogs. Which
statement describes what will most likely happen to the frog and mosquito populations over
time?
(A) The frog and mosquito populations will remain in equilibrium because the individual
organisms in each population have a steady supply of free energy.
(B) The mosquito population will start to decline first, followed by the frog population, because
free energy is only transferred in one direction, from smaller organisms to larger
organisms.
(C) The frog population will decrease in response to a decrease in the mosquito population
because frogs and mosquitoes have a predator-prey relationship and depend upon one
another for food.
(D) The frog and mosquito populations will both decline because individual organisms will
convert some available free energy into thermal energy, and a constant input of free
energy is needed to maintain the system.
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2.3 D: Free Energy of Ecosystems Quiz
3.
The diagram below shows the flow of energy through some species in an ecosystem.
Which statement best supports the information in the diagram?
(A) The individuals in species K have a high reproductive rate and a fast maturation rate
because they are a food source for all consumers in the ecosystem.
(B) Species J has the greatest total biomass of all species in the ecosystem since it obtains
energy from both primary and secondary consumers.
(C) Species F has the least amount of available free energy because it obtains its energy from
decomposers rather than producers.
(D) The removal of species G would be catastrophic to the other species in the ecosystem
because species G is a predator.
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2.3 D: Free Energy of Ecosystems Quiz
4.
The diagram below represents a partial food web for an ecosystem.
Which statement describes the most likely impact if species A is removed from the ecosystem?
(A) Species C, D, and E will all be equally affected because they all receive free energy from
species A.
(B) Species B will rapidly evolve to fill the niche left by species A and will become the only
primary producer.
(C) Species C and G will be most affected since the free energy for these species comes
directly or indirectly from species A.
(D) Species F, G, H, and J will be minimally affected because they receive free energy from
other sources rather than from species A.
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