handout 5 Flashcards
A parasite that feeds on the external surface of a host.
ecotparasite
The relative number of individuals of each age in a population.
age structure
The bright warning coloration of many animals with effective physical
or chemical defences
aposematic colouration
A type of mimicry in which a harmless species looks like a species that is
poisonous or otherwise harmful to predators
Batesian mimicry
Community organization in which mineral nutrients influence
community organization by controlling plant or phytoplankton
numbers, which in turn control herbivore numbers, which in turn
control predator numbers.
bottom-up model
he maximum population size that can be supported by the available
resources, symbolized as K.
carrying capacity
The tendency for characteristics to be more divergent in sympatric
populations of two species than in allopatric populations of the same
two species.
character displacement
The concept that when populations of two similar species contest for
the same limited resources, one population will use the resources more
efficiently and have a reproductive advantage that will eventually lead
to the elimination of the other population.
competitive exclusion
Camouflage that makes a potential prey difficult to spot against its
background.
cryptic colouration
In a stable population, a shift from high birth and death rates to low
birth and death rates
demographic transition
The number of individuals per unit area or volume
density
Referring to any characteristic that varies with population density.
density dependent
Referring to any characteristic that is not affected by population
density
density independent
Pattern of spacing among individuals within the boundaries of a
population.
dispersion
The concept that long food chains are less stable than short chains.
dynamic stability
hypothesis
The aggregate land and water area required by a person, city, or nation
to produce all of the resources it consumes and to absorb all of the
wastes it generates.
ecological footprint
The sum of a species’ use of the biotic and abiotic resources in its
environment
ecological niche
An organism that influences community structure by causing physical
changes in the environment.
ecosystem engineer
A parasite that lives within a host
endoparasite
The concept that the length of a food chain is limited by the inefficiency
of energy transfer along the chain
energetic hypothesis
The total evaporation of water from an ecosystem, including water
transpired by plants and evaporated from a landscape, usually
measured in millimetres and estimated for a year
evapotranspiration
Growth of a population in an ideal, unlimited environment, represented
by a J-shaped curve when population size is plotted over time
exponential population growth
The pathway along which food energy is transferred from trophic level
to trophic level, beginning with producers.
food chain
The interconnected feeding relationships in an ecosystem.
food web
The concept that moderate levels of disturbance can foster greater
species diversity than low or high levels of disturbance.
intermediate disturbance hypothesis
A relationship between individuals of two or more species in a
community
interspecific interaction
A species, often introduced by humans, that takes hold outside its
native range
invasive species
Reproduction in which adults produce offspring over many years; also
known as repeated reproduction
iteroparity
Selection for life history traits that are sensitive to population density;
also called density-dependent selection
k-selection
A species that is not necessarily abundant in a community yet exerts
strong control on community structure by the nature of its ecological
role or niche.
keystone species
An age-specific summary of the survival pattern of a population
life table
Population growth that levels off as population size approaches carrying
capacity.
logistic population growth
A group of spatially separated populations of one species that interact
through immigration and emigration
metapopulation
Reciprocal mimicry by two unpalatable species
mullerian mimicry
Maintains that communities change constantly after being buffeted by
disturbances
non-equilibrium
Occurs in an area where there were originally no organisms present and
where soil has not yet formed.
primary succession
Selection for life history traits that maximize reproductive success in
uncrowded environments; also called density-independent selection.
r-selection
The proportional abundance of different species in a community.
relative abundance
An age-specific summary of the reproductive rates in a population
reproductive table
The division of environmental resources by coexisting species such that
the niche of each species differs by one or more significant factors from
the niches of all co-existing species.
resource partitioning
A type of succession that occurs where an existing community has been
cleared by some disturbance that leaves the soil or substrate intact
secondart succession
Reproduction in which an organism produces all of its offspring in a
single event; also known as big-bang reproduction.
semelparity
An index of community diversity symbolized by H and represented by
the equation H = -(pA ln pA + pB ln pB + pC ln pC + …), where A, B, C … are
species, p is the relative abundance of each species, and ln is the
natural logarithm
shannon (diversity)
The biodiversity pattern that shows that the larger the geographic area
of a community is, the more species it has.
species-area curve
The number and relative abundance of species in a biological
community.
species diversity
The number of species in a biological community.
species richness
A plot of the number of members of a cohort that are still alive at each
age; one way to represent age-specific mortality
survivor curve
Community organization in which predation influences community
organization by controlling herbivore numbers, which in turn control
plant or phytoplankton numbers, which in turn control nutrient levels
top-down model
The different feeding relationships in an ecosystem, which determine
the route of energy flow and the pattern of chemical cycling
trophic structure
An organism that transmits pathogens from one host to another.
vector
A period of stability in population size, when additions to the
population through births and immigration are balanced by
subtractions through deaths and emigration
zero population growth (ZPG)
A disease-causing agent that is transmitted to humans from other
animals.
zoonotic pathogen
concept 14.1
dynamic biological processes influence population density, dispersion and demographics
concept 14.2
the exponential model describes population growth, in an idealized, unlimited environment
concept 14.3
the logistic model describes how a population grows more slowly as it nears carrying capacity
concept 14.4
life history traits are product of natural selection
concept 14.5
many factors that regulate population growth are density dependent
concept 14.6
the human population is no longer growing exponentially but is still growing rapidly
concept 15.1
community interactions are classified by whether they help, harm or have no effect on the species involved
concept 15.2
diversity and trophic structures characterize biological communities
concept 15.3
disturbance influences species diversity and composition
concept 15.4
biogeographic factors affect community diversity
concept 15.5
pathogens alter community structure locally and globally
A population is correctly defined as having which of the following characteristics? I. inhabiting the same general area; II. individuals belonging to the same species; III. possessing a constant and uniform density and dispersion
C. I and II only
An ecologist recorded 12 white-tailed deer, Odocoileus virginianus, per square mile in one woodlot and 20 per square mile on another woodlot. What was the ecologist comparing?
A. density.
To measure the population density of monarch butterflies occupying a particular park, 100 butterflies are captured, marked with a small dot on a wing, and then released. The next day, another 100 butterflies are captured, including the recapture of 20 marked butterflies. One would estimate the population to be
B. 500.
During the spring, you are studying the mice that live in a field near your home.
There are lots of mice in this field, but you realize that you rarely observe any
reproductive females. This most likely indicates
D. that you are observing immigrant mice.
A table listing such items as age, observed number of organisms alive each year, and
life expectancy is known as a (an)
A. life table.
Which of the following examples would most accurately measure the density of the population being studied?
E. counting the number of zebras from airplane census observations.
To measure the population of lake trout in a 250-hectare lake, 200 individuals were netted and marked with a fin clip, and then returned to the lake. The next week, the lake is netted again, and out of the 200 lake trout that are caught, 50 have fin clips. Using the capture-recapture estimate, the lake trout population size could be closest
to which of the following?
D. 800
Which of the following assumptions have to be made regarding the capture-
recapture estimate of population size? I. Marked and unmarked individuals have the same probability of being trapped; II. The marked individuals have thoroughly mixed with population after being marked; III. No individuals have entered or left the population by immigration or emigration, and no individuals have been added by birth or eliminated by death during the course of the estimate.
E. I, II, and III
Which of the following groups would be most likely to exhibit uniform dispersion?
A. red squirrels, who actively defend territories.
Imagine that you are managing a large ranch. You know from historical accounts that wild sheep used to live there, but they have been extirpated. You decide to reintroduce them. After doing some research to determine what might be an appropriately sized founding population, you do so. You then watch the population increase for several generations, and graph the number of individuals (vertical axis)
against the number of generations (horizontal axis). The graph will appear as
D. a ʺJʺ, increasing with each generation.
As N approaches K for a certain population, which of the following is predicted by the logistic equation?
B. The growth rate will approach zero.
The Allee effect is used to describe a population that
A. has become so small that it will have difficulty surviving and reproducing
Pacific salmon or annual plants illustrate which of the following?
E. semelparous
Which of the following describes having more than one reproductive episode during a lifetime?
D. iteroparous
Which of the following characterizes relatively K-selected populations?
A. offspring with good chances of survival
Your friend comes to you with a problem. It seems his shrimp boats aren’t catching nearly as much shrimp as they used to. He can’t understand why because originally he caught all the shrimp he could handle. Each year he added a new boat, and for a long time each boat caught tons of shrimp. As he added more boats, there came a time when each boat caught somewhat fewer shrimp, and now, each boat is catching a lot less shrimp. Which of the following topics might help your friend
understand the source of his problem?
A. density-dependent population regulation and intrinsic characteristics of
population growth.
Which of the following is an incorrect statement about the regulation of
populations?
B. Density-independent factors have an increasingly greater effect as a
population’s density increases.
Which of the following is a density-independent factor limiting human population
growth?
B. earthquakes
Most ecologists believe that the average global carrying capacity for the human
population is between
C. 10 and 15 billion
An ecological footprint is a construct that is useful
A. for a person living in a developed nation to consider to make better choices when using global food and energy resources
Which of the following statements is consistent with the principle of competitive
exclusion?
D. 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 same
B. niche
The sum total of an organism’s interaction with the biotic and abiotic resources of its environment is called its
E. ecological niche
Which of the following best describes resource partitioning?
B. Slight variations in niche allow similar species to co-exist
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
Which of the following is an example of cryptic colouration?
E. a ʺwalking stickʺ insect that resembles a twig.
Which of the following is an example of Müllerian mimicry?
A. two species of unpalatable butterfly that have the same colour pattern.
Which of the following is an example of Batesian mimicry?
C. a non-venomous snake that looks like a venomous snake
Which of the following terms best describes the interaction between termites and
the protozoans that feed in their gut?
B. mutualism
Which of the following examples best describes an ecological community?
B. The interactions of all the plant and animal species inhabiting a 2-hectare
forest
Historically, most ecological research on the community has focused on which of the following?
A. competition or predation between two different species.
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 behaviours best illustrate which of the following ecological concepts?
B. resource partitioning
The species richness of a community refers to the
C. number of different species
With a few exceptions, most of the food chains studied by ecologists have a
maximum of how many links?
C. 5.
The energetic hypothesis and dynamic stability hypothesis are explanations to
account for
B. the length of food chains
In a tide pool, 15 species of invertebrates were reduced to eight after one species
was removed. The species removed was likely a(n)
D. keystone species
Biomanipulation can best be described as
A. removing many of the next higher trophic level organisms so that the
struggling trophic level below can recover
Which of the following is considered by ecologists a measure of the ability of a
community either to resist change or to recover to its original state after change?
A. stability.
Zoonotic disease
B. is caused by pathogens that are transferred from other animals to humans by direct contact or by means of a vector
Which of the following studies would shed light on the mechanism of spread of H5N1 from Asia?
A. Perform cloacal or saliva smears of migrating waterfowl to monitor whether
any infected birds show up in Alaska
