Part 1 of 1 – 100.0
Points
Question 1 of 20
5.0 Points
Gause’s “competitive exclusion principle” states
that:
A. when two species
occur together, competition is always prevented by some behavioral adjustment.
B. no two species
can coexist indefinitely.
C. no two competing
species can coexist indefinitely.
D. no two species
with identical niches can coexist indefinitely.
Question 2 of 20
5.0 Points
In the Lotka-Volterra competition equations, if a21 > 1,
then:
A. the population
growth rate of species 2 is reduced more by each individual of species 1 than
by each individual of species 2.
B. the population
growth rate of species 2 is reduced more by each individual of species 2 than
by each individual of species 1.
C. the population
growth rate of species 2 is reduced equally by individuals of either species 1
or species 2.
D. we would also
have to know the value of K2 to decide which of the above is true.
Question 3 of 20
5.0 Points
Analysis of the Lotka-Volterra competition model implies
that two competitors can coexist only when:
A. interspecific
competition is stronger than intraspecific competition.
B. intraspecific
competition is stronger than interspecific competition.
C. intraspecific and
interspecific competition are equally strong.
D. predation or
parasitism is stronger than interspecific competition.
Question 4 of 20
5.0 Points
Two species occurring together in the same place are said to
be:
A. competitors.
B. precocial.
C. mutualists.
D. sympatric.
Question 5 of 20
5.0 Points
The __________ niche defines the physical conditions under
which a species might live, in the absence of interaction with other species.
A. functional
B. realized
C. principle
D. fundamental
Question 6 of 20
5.0 Points
The process of evolution toward niche divergence in the face
of competition is called:
A. niche
displacement.
B. niche evolution.
C. character
displacement.
D. character evolution.
Question 7 of 20
5.0 Points
A species feeding on the tissue of its host, while not
killing it directly, is a:
A. predator.
B. parasite.
C. parasitoid.
D. cannibal.
Question 8 of 20
5.0 Points
A “negatively phototaxic” amphipod will swim:
A. away from
parasitic worms.
B. towards parasitic
worms.
C. away from
competing amphipods.
D. away from light.
Question 9 of 20
5.0 Points
The presence of parasitic protozoa in a culture of competing
Tribolium castaneum and T. confusum:
A. increases the
likelihood of coexistence.
B. decreases the
likelihood of coexistence.
C. has no effect on
the outcome of competition.
D. can reverse the
outcome of competition.
Question 10 of 20
5.0 Points
The infestation of prickly pear cactus (Opuntia) in
Australia was controlled by the release of a moth, Cactoblastis, which impacts
cactus populations because it:
A. consumes cactus
seeds.
B. consumes cactus
pads.
C. introduces, as it
attacks, fungi and bacteria that attack cactus pads.
D. both consumes
cactus pads and introduces, as it attacks, fungi and bacteria that attack
cactus pads.
Question 11 of 20
5.0 Points
The standard error of the mean is equal to:
A. the sample variance
divided by the sample size.
B. the sample
variance divided by the square root of the sample size.
C. the sample
standard deviation divided by the square root of the sample size.
D. twice the square
root of the sample size.
Question 12 of 20
5.0 Points
Gause’s experiments with Paramecium and Didinium showed:
A. extinction of the
predator, followed by extinction of the prey, in all habitats.
B. coexistence of
predator and prey with oscillating population sizes, but only in the presence
of refuges and predator reservoirs.
C. coexistence of
predator and prey, but with oscillating population sizes, in all habitats.
D. coexistence of
predator and prey at fairly constant population sizes, but only in the presence
of refuges and predator reservoirs.
Question 13 of 20
5.0 Points
Periodical cicadas spend 13 or 17 years:
A. feeding in tree
twigs before emerging as adults.
B. feeding on tree
roots before emerging as adults.
C. as adults before
laying eggs.
D. in a resistant,
resting egg before hatching as larvae.
Question 14 of 20
5.0 Points
Schistosoma flukes attack their human hosts when those
humans:
A. consume infected
freshwater snails.
B. consume infected
fish.
C. consume plant
tissue bearing spores.
D. bathe in water
containing infective cercariae.
Question 15 of 20
5.0 Points
Use of Procambarus crayfish to combat schistosomiasis in
Africa:
A. is likely to be
effective, and poses no important ecological risks.
B. is likely to be
effective, but poses ecological risks because Procambarus is not native to
Africa.
C. is unlikely to be
effective, because the crayfish seem to eat infected snails only in the
laboratory.
D. is unlikely to be
effective, because the crayfish are just as suitable as hosts for the parasite
as were the snails.
Question 16 of 20
5.0 Points
An interaction between individuals of different species that
benefit both partners is called:
A. commensalism.
B. predation.
C. exploitation.
D. mutualism.
Question 17 of 20
5.0 Points
__________ mutualism describes a relationship where species
are so dependent on their mutualistic relationship they cannot live in its
absence.
A. Obligate
B. Critical
C. Facultative
D. Dispensable
Question 18 of 20
5.0 Points
Mycorrhizal fungi (directly) help their plant partners
acquire:
A. sugars.
B. sunlight.
C. seed dispersal.
D. soil nutrients.
Question 19 of 20
5.0 Points
Ant-acacia trees provide several services to their
mutualistic ant partners. These include:
A. enlarged thorns
to host ant colonies.
B. nectar from
foliar nectaries.
C. nectar from
floral nectaries.
D. both enlarged
thorns to host ant colonies and nectar from foliar nectaries.
Question 20 of 20
5.0 Points
The major benefit obtained by aspen sunflower, Helianthella
quinquenervis, from its ant mutualists is:
A. improved
attraction of pollinators.
B. reduced loss of
leaf tissue to herbivorous insects.
C. more efficient
extraction of soil nutrients.
D. reduced losses of
seeds to seed predators.