PCB 3043 Exam Questions and Answers
Graded A+
Ecology - Correct answer-The scientific study of the interactions that determine the
distribution & abundance of organisms
Rain Shadow - Correct answer-An area of low precipitation on the side of a
mountain away from predominant winds
Community (not association) - Correct answer-An assemblage of populations that
interact with one another in a prescribed area or habitat
sere - Correct answer-a series of stages of community change in a particular area
leading toward a stable state (we want the pattern, not the process)
Trophic cascade - Correct answer-When increasing the abundance of a top predator
causes the next trophic level to decline, the level below that to increase, etc.
Basal species - Correct answer-Species in a food web that do not consume other
species, but are either photosynthetic or detritivores
Allee effect - Correct answer-A phenomenon of low densities, where the per-capita
growth rate declines at low population densities
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,Functional Response - Correct answer-How the capture rate of prey by a predator
depends on the abundance of the prey
Gamma diversity - Correct answer-The numbers & relative abundances of species
across a region that includes
turnover - Correct answer-The sinking & mixing action that occurs in many water
systems due to the relationship between density & water temperature
Realized niche - Correct answer-The needs & role of a species in a habitat when
competition & other biotic interactions are present
Community resilience - Correct answer-A mesure of the ability of a community to
persist in the presence of perturbations or disturbances
Metapopulation - Correct answer-A group of several local populations, linked by
immigration & extinction
Commensalism - Correct answer-An interspecific interaction, where one species
gains a benefit such as habitat or shelter while the other species is unaffected
Exponential of DI growth - Correct answer-Population growth when there is a
constant per-capita growth rate
Environmental stochasticity - Correct answer-Variation in birth & death rates
caused by changes in climatic factors such as temperature & rain
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, parasite - Correct answer-Species that consume only part of a living prey, but
usually specialize on one to a few prey during their lifetime
Endemic - Correct answer-When a plant or animal is restricted to a certain area
Acidification - Correct answer-A decrease in the pH of the oceans due to an
increase in carbonate in water as atmospheric CO2 levels increase
Diffusion - Correct answer-Gradual expansion of a species from an initial sigal
point into surrounding areas
Resilience - Correct answer-The ability of a community to persist in the presence
of perturbations
Beta Diversity - Correct answer-variation in species composition from one habitat
to another within a region
Density dependent or logistic - Correct answer-When per-capita growth rates
decline as a linear function of population density
Allelopathy - Correct answer-When organisms produce biochemicals that influence
the growth or reproduction of other organisms around them
Batesian mimicry - Correct answer-When harmless organisms resemble poisonous
or distasteful organisms in order to reduce predation
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Graded A+
Ecology - Correct answer-The scientific study of the interactions that determine the
distribution & abundance of organisms
Rain Shadow - Correct answer-An area of low precipitation on the side of a
mountain away from predominant winds
Community (not association) - Correct answer-An assemblage of populations that
interact with one another in a prescribed area or habitat
sere - Correct answer-a series of stages of community change in a particular area
leading toward a stable state (we want the pattern, not the process)
Trophic cascade - Correct answer-When increasing the abundance of a top predator
causes the next trophic level to decline, the level below that to increase, etc.
Basal species - Correct answer-Species in a food web that do not consume other
species, but are either photosynthetic or detritivores
Allee effect - Correct answer-A phenomenon of low densities, where the per-capita
growth rate declines at low population densities
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
,Functional Response - Correct answer-How the capture rate of prey by a predator
depends on the abundance of the prey
Gamma diversity - Correct answer-The numbers & relative abundances of species
across a region that includes
turnover - Correct answer-The sinking & mixing action that occurs in many water
systems due to the relationship between density & water temperature
Realized niche - Correct answer-The needs & role of a species in a habitat when
competition & other biotic interactions are present
Community resilience - Correct answer-A mesure of the ability of a community to
persist in the presence of perturbations or disturbances
Metapopulation - Correct answer-A group of several local populations, linked by
immigration & extinction
Commensalism - Correct answer-An interspecific interaction, where one species
gains a benefit such as habitat or shelter while the other species is unaffected
Exponential of DI growth - Correct answer-Population growth when there is a
constant per-capita growth rate
Environmental stochasticity - Correct answer-Variation in birth & death rates
caused by changes in climatic factors such as temperature & rain
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
, parasite - Correct answer-Species that consume only part of a living prey, but
usually specialize on one to a few prey during their lifetime
Endemic - Correct answer-When a plant or animal is restricted to a certain area
Acidification - Correct answer-A decrease in the pH of the oceans due to an
increase in carbonate in water as atmospheric CO2 levels increase
Diffusion - Correct answer-Gradual expansion of a species from an initial sigal
point into surrounding areas
Resilience - Correct answer-The ability of a community to persist in the presence
of perturbations
Beta Diversity - Correct answer-variation in species composition from one habitat
to another within a region
Density dependent or logistic - Correct answer-When per-capita growth rates
decline as a linear function of population density
Allelopathy - Correct answer-When organisms produce biochemicals that influence
the growth or reproduction of other organisms around them
Batesian mimicry - Correct answer-When harmless organisms resemble poisonous
or distasteful organisms in order to reduce predation
©COPYRIGHT 2025, ALL RIGHTS RESERVED 3
