A harmless fly develops colouration that makes it look like a poisonous wasp. This is an example of:
Mullerian mimicry
Batesian mimicry
competitive avoidance
character displacement
Which of the following interspecific interaction is NOT +/–?
competition
predation
herbivory
parasitism
Allopatric species that use similar resources are likely to display character displacement.
Which of the following is the BEST example of a biological COMMUNITY?
black bears in British Columbia and Ontario
polar bears, seals and fish in Western Hudson Bay
a group of zebra mussels in a lake
none of the above
A prey species starts producing a toxin in its skin after exposure to a predator. The toxin was not present until the predator arrives. This is an example of:
a constitutive defence
a standing defence
aposematic colouration
an inducible defence
Three species of poisonous frogs have very similar colouration. This is an example of:
predator avoidance
colouration mimicry
When two species compete, which of the following is a possible outcome?
competitive exclusion of one species
niche differentiation
all of the above
Competitive exclusion often results from symmetric competition.
Why don't herbivores eat all of the primary production on Earth?
herbivore populations are limited to available nitrogen
some plant tissues are toxic
herbivore populations are limited by predators
Interspecific interaction between species (ie. parasitism, mutualism, competition) are constant. Once established, they do not change.
Dominance by a few species is more likely in a less diverse community.
All communities have dominant species.
Species diversity has two components: 1) species richness; 2) relative abundance/evenness.
Which community is most diverse? HINT: Read ‘25A’ as “25 individuals of Species A” and ‘25B’ as “25 individuals of Species B”, etc.
community 4: 25A, 25B, 25C
community 3: 25A, 20B, 50C, 5D
community 1: 25A, 25B, 25C, 25D
community 2: 20A, 20B, 20C, 20D, 20E
Which one of these curves is representative of the most diverse community?
Potash Brook
Snipe Island Brook
Centennial Brook
all are the same
Data on an individual species’ frequency, density, basal area and biomass could be used to calculate what quantity?
importance
Simpson's Index
richness
evenness
Which of the following statements about diversity indices is FALSE?
they incorporate data on both number of species and evenness of species
the Shannon Index gives more weight to rare species
evenness varies between 0 and 1
they do not account for dominant species
Keystone species influence community structure because they are always abundant.
If the presence of a keystone predator increases diversity, it is likely preying on:
bioengineers
superior competitors
tolerant competitors
inferior competitors
Keystone species can affect their communities by:
affecting inter-species interaction
modifying habitat
affecting inter-community interactions
In a three-step food chain subject to top-down control, you have fish that eat zooplankton that eat algae. What is likely to happen if the fish are removed?
algae abundance increases
zooplankton abundance decreases
algae abundance decreases
You add fertilizer to an experimental plot. Plant growth increases, and you observe that the number of herbivores and carnivores increases. This is an example of:
bottom-up control
top-down control
the energetic hypothesis
omnivory
Several species of fish in a lake eat plankton. This group can be referred to as:
omnivores
a cohort
a guild
a feeding group
A species is fished out of a lake, and another species fills its niche and role in the food web. This is an example of:
functional redundancy
facultative redundancy
Understanding how the decline of sea otters affected kelp forests in the Pacific leads us to conclude that:
sea otters are subject to density-independent factors
sea otters are bioengineers
sea otters are keystone prey
sea otters are keystone predators
If the intermediate disturbance hypothesis is true, communities that experience intermediate disturbance levels have:
shorter food chains
higher species diversity
more competitive exclusion
no slow-colonizing species
An early colonizing plant species modifies the soil environment such that larger vascular plants can colonize. This is an example of:
negative allelopathy
facilitation
tolerance
inhibition
In which of the following is competition used to explain successional patterns?
both A and B
If the initial floristic composition hypothesis is true, we would expect community succession to:
end in a predictable, stable climax community
not depend on competition
be affected by which species arrive first
In succession, species diversity always increases over time.
Which of the following statements about the resource-ratio hypothesis is TRUE:
species that grow quickly are favoured throughout succession
availability of nutrients decreases over time
availability of light decreases over time
competition does not affect successional outcomes
A farmer cuts down part of a forest to make a field. The abrupt border between the forest and field is BEST characterized as:
an ecotone
a core area
an induced edge
an inherent edge
A farmer cuts down part of a forest to make a field, but plants species diversity remains constant for almost 10 years before deciding. This is BEST characterized as an example of:
matrix effects
a border effect
the relaxation effect
area-intensive species
Two species cannot coexist permanently in a community if their niches are identical.