1) Which of the following statements is consistent with the principle of competitive exclusion?
Even a slight reproductive advantage will eventually lead to the elimination of the less well
adapted of two competing species
According to the competitive exclusion principle, two species cannot continue to occupy the
The sum total of an organism's interaction with the biotic and abiotic resources of its
environment is called its
A species of fish is found to require a certain water temperature, a particular oxygen content
of the water, a particular depth, a rocky substrate on the bottom, and a variety of nutrients in the
form of microscopic plants and animals to thrive. These requirements describe it
B) ecological niche.
8) Which of the following best describes resource partitioning?
B) Slight variations in niche allow similar species to coexist.
As you study two closely related predatory insect species, the two-spot and the three-spot
avenger beetles, you notice that each species seeks prey at dawn in areas without the other
species. However, where their ranges overlap the two-spot avenger beetle hunts at night and the
three-spot hunts in the morning. When you bring them into the laboratory, their offspring behave
in the same manner. You have discovered an example of
B) character displacement.
10) Resource partitioning would be most likely to occur between
B) sympatric populations of species with similar ecological niches.
11) Which of the following is an example of cryptic coloration?
E) a "walking stick" insect that resembles a twig
12) Which of the following is an example of Müllerian mimicry?
A) two species of unpalatable butterfly that have the same color pattern
13) Which of the following is an example of Batesian mimicry?
C) a non-venomous snake that looks like a venomous snake
Dwarf mistletoes are flowering plants that grow on certain forest trees. They obtain nutrients
and water from the vascular tissues of the trees. The trees derive no known benefits from the
dwarf mistletoes. Which of the following best describes the interactions between dwarf
mistletoes and trees
Evidence shows that some grasses benefit from being grazed. Which of the following terms
would best describe this plant-herbivore interaction?
Which of the following terms best describes the interaction between termites and the
protozoans that feed in their gut?
Which of the following types of species interaction is correctly paired with its effects on the
density of the two interacting populations?
C) commensalism: as one increases the other stays the same
White-breasted nuthatches and Downy woodpeckers both eat insects that hide in the furrows
of bark in hardwood trees. The Downy woodpecker searches for insects by hunting from the
bottom of the tree trunk to the top, while the White-breasted nuthatch searches from the top of
the trunk down. These hunting behaviors best illustrate which of the following ecological
B) resource partitioning
Monarch butterflies are protected from birds and other predators but the cardiac glycosides
they incorporate into their tissues are from eating milkweed when they were in their caterpillar
stage of development. The wings of a different species of butterfly, the Viceroy, look nearly
identical to the Monarch so predators that have learned not to eat the bad-tasting Monarch avoid
Viceroys as well. This example best describes
C) Batesian mimicry.
28) All of the following have been used by plants to avoid being eaten except
D) producing tissues that have unappealing colors.
29) The species richness of a community refers to the
B) number of different species.
With a few exceptions, most of the food chains studied by ecologists have a maximum of
how many links
Which of the following members of a marine food chain occupies a similar tropic level to a
grasshopper in a terrestrial food chain?
Approximately how many kg of carnivore production can be supported by a field plot
containing 2000 kg of plant material?
35) The dominant species in a community is
D) the species that contributes the most biomass to the community.
In a tide pool, 15 species of invertebrates were reduced to eight after one species was
removed. The species removed was likely a(n)
B) keystone species.
Elephants are not the most common species in African grasslands. The grasslands contain
scattered woody plants, but they are kept in check by the uprooting activities of the elephants.
Take away the elephants, and the grasslands convert to forests or to shrublands. The newly
growing forests support fewer species than the previous grasslands. Which of the following
describes why elephants are the keystone species in this scenario?
Essentially all of the other species depend on the presence of the elephants to maintain the
When lichens grow on bare rock, they may eventually accumulate enough organic material
around them to supply the foothold for later rooted vegetation. These early pioneering lichens
can be said to do what to the later arrivals?
44) According to the Shannon Diversity Index, which block would show the greatest diversity?
) Which of the following is the most accepted hypothesis as to why invasive species take over
communities into which they have been introduced?
Invasive species are not held in check by the predators and agents of disease that have always
been in place for the natives.
48) According to the nonequilibrium model,
E) communities are constantly changing after being influenced by disturbances.
50) You are most likely to observe primary succession in a terrestrial community when you visit
D) recently created volcanic island.
51) Which of the following describes the relationship between ants and acacia trees?
Which of the following describes the relationship between legumes and nitrogen-fixing
Which of the following describes a successional event in which one organism makes the
environment more suitable for another organism?
56) A community's actual evapotranspiration is a reflection of
A) solar radiation, temperature, and water availability.
1) The feeding relationships among the species in a community determine the community's
C) trophic structure.
2) The principle of competitive exclusion states that
D) two species that have exactly the same niche cannot coexist in a community.
3) Keystone predators can maintain species diversity in a community if they
B) prey on the community's dominant species.
4) Food chains are sometimes short because
C) most of the energy in a trophic level is lost as it passes to the next higher level.
5) Based on the intermediate disturbance hypothesis, a community's species diversity is
C) increased by moderate levels of disturbance.
6) Which of the following could qualify as a top-down control on a grassland community?
D) effect of grazing intensity by bison on plant species diversity
) The most plausible hypothesis to explain why species richness is higher in tropical than in
temperate regions is that
B) tropical regions generally have more available water and higher levels of solar radiation.
According to the equilibrium model of island biogeography, species richness would be
greatest on an island that is
C) large and close to a mainland.