Download Squirrels feed mainly on acorns in an oak forest ecosystem

PROCTOR VERSION
2.3 C: Free Energy of Populations Quiz
1.
Squirrels feed mainly on acorns in an oak forest ecosystem. However, many species of oak trees
do not produce acorns every year if conditions are unfavorable. Which statement predicts the
most likely effect this uneven production of acorns will have on a squirrel population?
(A) The squirrel population will fluctuate from year to year because the available free energy
individuals need for survival is inconsistent.
Rationale:
This answer suggests the student understands that an inconsistent supply of free energy
causes populations to fluctuate because a constant supply of free energy is required to
sustain the organisms within a population.
(B) The squirrel population will slowly increase over time because the available free energy
individual squirrels need will increase as the rate of competition increases.
Distractor Rationale:
This answer suggests the student may understand that competition for natural resources
increases an individual’s need for free energy, but does not understand that an increase in
competition for free energy will not increase the available free energy, or that the population
will likely decrease if competition increases.
(C) The squirrel population will fluctuate from year to year because individual squirrels will use
more free energy for reproduction in years with harsh weather than in years with mild
weather.
Distractor Rationale:
This answer suggests the student may understand that changes in available free energy
cause populations to fluctuate, but does not understand that reproduction requires more
free energy and that an animal who is trying to conserve free energy would not likely
reproduce.
(D) The squirrel population will slowly decrease over time because individual squirrels will use
more food energy to produce fats and will have less free energy available for other
processes.
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PROCTOR VERSION
2.3 C: Free Energy of Populations Quiz
Distractor Rationale:
This answer suggests the student may understand that animals convert free energy from
food into fats, but does not understand that animals convert extra free energy into fats only
during periods when there is excess free energy and that this conversion does not affect the
amount of free energy available for other processes.
Aligned to: LO 2.3 CA 2.3: Predict Free Energy
2.
The climatogram below shows the average monthly precipitation and temperature for an
ecosystem in the southwestern United States.
Torpor is a physiological state characterized by a decrease in the metabolic rate of an animal
during long periods of inactivity. A population of animals in an area in the southwestern
ecosystem experience torpor during certain times of year. Which statement best explains when
and why the individuals in the population will likely experience torpor in this type of environment?
(A) The individuals in the population experience torpor from December to January in order to
conserve free energy because the cold temperatures and high precipitation reduce the
amount of free energy that is stored in plants.
Distractor Rationale:
This answer suggests the student may understand that cold temperatures cause the
individuals in some populations to experience torpor, but does not understand that the
amount of free energy stored in plants does not tend to be reduced during this time.
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PROCTOR VERSION
2.3 C: Free Energy of Populations Quiz
(B) The individuals in the population experience torpor from June to August because the high
temperatures and low precipitation produce environmental conditions that are unfavorable
for producers to capture free energy and transfer it into the environment.
Rationale:
This answer suggests the student understands that there is less available free energy in
the summer months due to the hot, dry conditions and little precipitation because
environmental conditions make plants less likely to use needed stored water for
photosynthesis to capture free energy during this time and it is advantageous for the
individuals in a population to experience torpor together to reduce competition.
(C) The individuals in the population experience torpor from November to February because the
cold temperatures and high precipitation would cause the animal to use more free energy in
order to maintain homeostasis.
Distractor Rationale:
This answer suggests the student may understand that cooler temperatures tend to reduce
available free energy in ecosystems, but does not understand that, in this situation, the
mild, wetter conditions would promote plant growth and increase the availability of free
energy in the ecosystem.
(D) The individuals in the population experience torpor from March to May because free energy
is not entering the environment during this time and more energy would be spent trying to
find sources of food than could be obtained from the environment when free energy is not
entering it.
Distractor Rationale:
This answer suggests the student may understand that an animal is more likely to
experience torpor when the investment of energy trying to find food is greater than the
energy harvested from food, but does not understand that rainfall and temperatures are
still favorable in March and April, and likely most of May.
Aligned to: LO 2.3 CA 2.3: Predict Free Energy
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PROCTOR VERSION
2.3 C: Free Energy of Populations Quiz
3.
Zebra mussels are small freshwater mollusks that were accidentally introduced to many lakes
and rivers in the United States from Europe. Zebra mussels are filter feeders that consume large
quantities of small food particles such as phytoplankton and zooplankton. Butterfly mussels are
native mollusks with feeding habits that are similar to those of zebra mussels. Which statement
best predicts how a population of butterfly mussels in a lake will be affected by the introduction of
zebra mussels?
(A) The butterfly mussel population will increase because the butterfly mussels will adapt to fit
an environmental niche in which additional free energy is available.
Distractor Rationale:
This answer suggests the student may understand that some species may adapt to a new
niche as a possible outcome of increased competition, but does not understand that most
organisms are not able to adapt to fit a niche just because more free energy is available in
that niche.
(B) The butterfly mussel population will decrease because overcrowding will force the butterfly
mussels to migrate to a new location that has less free energy available.
Distractor Rationale:
This answer suggests the student may understand that some species migrate to a new
location if the reduction in free energy becomes too great at certain times of the year, but
does not understand that migration is not an option for most organisms that live in a lake
and that most native species will experience a reduction in population when competition for
free energy comes from nonnative (invasive) species.
(C) The butterfly mussel population will increase because the butterfly mussels will be able to
capture additional free energy from parasitizing the zebra mussels.
Distractor Rationale:
This answer suggests the student may understand that some species can benefit from an
invasive species, but does not understand that when an invasive species competes for
free energy with a native species, the native species will be negatively impacted.
(D) The butterfly mussel population will decrease because the butterfly mussels will be unable to
attain enough free energy due to increased competition from the zebra mussels.
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PROCTOR VERSION
2.3 C: Free Energy of Populations Quiz
Rationale:
This answer suggests the student understands that a population will likely decrease if
another species increases the competition for the available free energy in the environment.
Aligned to: LO 2.3 CA 2.3: Predict Free Energy
4.
The masked booby is a marine bird that lives in the Galápagos Islands. A female masked booby
typically lays two eggs each year. Once both eggs hatch, the larger of the two offspring pushes
the smaller offspring out of the nest, eventually causing it to die. The parent birds allow this
behavior to happen. Which prediction would most likely occur if the smaller offspring were placed
back in the nest?
(A) The population would stay the same because the parents would be unable to provide
enough food for two offspring.
Rationale:
This answer suggests the student understands that the size of a population is limited by the
amount of free energy available to the organisms in the environment and that the number of
chicks that can survive is based on the amount of free energy the parents are able to obtain
from the environment.
(B) The population would increase at an exponential rate because twice the number of offspring
would be produced each year.
Distractor Rationale:
This answer suggests the student may understand that doubling the number of offspring
each year would lead to exponential growth, but does not understand that the population
cannot increase indefinitely and that the survival rate of offspring would decrease because
the supply of free energy is limited in the environment as parents would be unable to supply
each chick with enough free energy for survival.
(C) The population would increase slowly because it would take time for the parents to adapt to
simultaneously raising two chicks.
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PROCTOR VERSION
2.3 C: Free Energy of Populations Quiz
Distractor Rationale:
This answer suggests the student may understand that a species can adapt to some
environmental changes over time, but does not understand that the species cannot likely
adapt to raising more offspring because the number of offspring that can be produced each
year is directly related to the amount of free energy the parents are able to obtain from the
environment.
(D) The population would stay the same even though more offspring would survive each year
because more adults would die trying to obtain food for their offspring.
Distractor Rationale:
This answer suggests the student may understand that the population would stay the same
due to limited food resources (free energy), but does not understand that the rate of
offspring mortality would increase because, even if there are fewer adults in the environment
that require free energy, the offspring depend on adults for food, and one parent would likely
be unable to obtain enough free energy for itself and two chicks.
Aligned to: LO 2.3 CA 2.3: Predict Free Energy
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