CHAPTER 40 PT 2 Flashcards

A population is correctly defined as having which of the following characteristics?
I. inhabiting the same general area
II. belonging to the same species
III. possessing a constant and uniform density and dispersion
A) I only
B) III only
C) I and II only
D) II and III only
E) I, II, and III

An ecologist recorded 12 white-tailed deer, Odocoileus virginianus, per square mile in one
woodlot and 20 per square mile in another woodlot. What was the ecologist comparing?
A) density
B) dispersion
C) carrying capacity
D) cohorts
E) range

Uniform spacing patterns in plants such as the creosote bush are most often associated with
A) chance.
B) patterns of high humidity.
C) the random distribution of seeds.
D) competitive interaction between individuals of the same population.
E) the concentration of nutrients within the population's range.

Which of the following groups would be most likely to exhibit uniform dispersion?
A) red squirrels, who actively defend territories
B) cattails, which grow primarily at edges of lakes and streams
C) dwarf mistletoes, which parasitize particular species of forest trees
D) moths, in a city at night
E) lake trout, which seek out cold, deep water high in dissolved oxygen

To construct a reproductive table for a sexual species, one needs to
A) assess sperm viability for the males in the population.
B) keep track of all of the offspring of a cohort.
C) keep track of the females in a cohort.
D) keep track of all of the offspring of the females in a cohort.
E) analyze the ratio of deaths to births in a cohort.

Which of the following examples would most accurately measure the density of the
population being studied?
A) counting the number of prairie dog burrows per hectare
B) counting the number of times a 1-kilometer transect is intersected by tracks of red squirrels
after a snowfall
C) counting the number of coyote droppings per hectare
D) counting the number of moss plants in 1-m2 quadrats
E) counting the number of zebras from airplane census observations.

Long-term studies of Belding's ground squirrels show that immigrants move nearly 2 km
from where they are born and become 1-8% of the males and 0.7-6% of the females in other
populations. On an evolutionary scale, why is this significant?
A) These immigrants make up for the deaths of individuals, keeping the other populations' size
stable.
B) Young reproductive males tend to stay in their home population and are not driven out by
other territorial males.
C) These immigrants provide a source of genetic diversity for the other populations.
D) Those individuals that emigrate to these new populations are looking for less crowded
conditions with more resources.
E) Gradually, the populations of ground squirrels will move from a clumped to a uniform
population pattern of dispersion.

Which of the following sets of measurements would best describe a population’s physical
structure and vital statistics?
A) density, dispersion, and demographics
B) gene frequency over time and the ratio of reproductive to nonreproductive individuals
C) annual precipitation averages and mean annual temperatures
D) minimum and maximum amounts of precipitation and annual temperature extremes
E) ratio of predators and the number of immigrants and emigrants

Which of the following scenarios would provide the most legitimate data on population
density?
A) Count the number of nests of a particular species of songbird and multiply this by a factor that
extrapolates these data to actual animals.
B) Count the number of pine trees in several randomly selected 10-m by 10-m plots and
extrapolate this number to the fraction of the study area these plots represent.
C) Use the mark-and-recapture method to estimate the size of the population.
D) Calculate the difference between all of the immigrants and emigrants to see if the population
is growing or shrinking.
E) Add the number of births and subtract the individuals that die to see if the population's density
is increasing or decreasing.

41) Which of the following is the best natural example of uniform distribution?
A) bees collecting pollen in a wildflower meadow
B) snails in an intertidal zone at low tide
C) territorial songbirds in a mature forest during mating season
D) mushrooms growing on the floor of an old-growth forest
E) a cultivated cornfield in the Midwest

Which of the following choices would most likely promote random distribution?
A) territorial species
B) species that secrete chemicals to attract or inhibit other individuals
C) flocking and schooling behaviors
D) spacing during the breeding season
E) homogeneous chemical and physical factors in the environment

Which of the following best defines a cohort?A) a group of individuals that inhabits a small isolated region within the range for the species
B) all of the individuals that are annually added to a population by birth and immigration
C) the reproductive males and females within the population
D) a group of the individuals from the same age group, from birth until they are all dead
E) the number of individuals that annually die or emigrate out of a population

Why do some invertebrates, such as lobsters, show a "stair-step" survivorship curve?
A) Many invertebrates mate and produce offspring on multiyear cycles.
B) Within a species of invertebrates, younger individuals have a higher survivorship than older
individuals.
C) Many invertebrates molt in order to grow, and they are vulnerable to predation during their
"soft shell" stage.
D) Many invertebrate species have population cycles that go up and down according to the
frequency of sunspots.
E) The number of fertilized eggs that mature to become females in many species of invertebrates
is based on ambient temperature.

A population of ground squirrels has an annual per capita birth rate of 0.06 and an annual per
capita death rate of 0.02. Calculate an estimate of the number of individuals added to (or lost
from) a population of 1,000 individuals in one year.
A) 120 individuals added
B) 40 individuals added
C) 20 individuals added
D) 400 individuals added
E) 20 individuals lost

Starting from a single individual, what is the size of a population of bacteria that reproduce
by binary fission every 20 minutes at the end of a 2-hour time period? (Assume unlimited
resources and no mortality.)
A) 8
B) 16
C) 32
D) 64
E) 128

Which of the following is the equation for zero population growth (ZPG)?
A) b = m or r = 0
B) dN/dt = rN
C) dN/dt = rmax N (K - N)/K
D) dN/dt = rmax N
E) dN/dt = 1.0N

In July 2008, the United States had a population of approximately 302,000,000 people. How
many Americans were there in July 2009, if the estimated 2008 growth rate was 0.88%?
A) 2,700,000
B) 5,500,000
C) 303,000,000
D) 304,700,000
E) 2,710,800,000

In 2008, the population of New Zealand was approximately 4,275,000 people. If the birth
rate was 14 births for every 1,000 people, approximately how many births occurred in New
Zealand in 2008?
A) 6,000
B) 42,275
C) 60,000
D) 140,000
E) 600,000

Consider two forests: one is an undisturbed old-growth forest, whereas the other has recently
been logged. In which forest are species likely to experience exponential growth, and why?
A) Old growth, because the stable conditions would favor exponential growth of all species in
the forest.
B) Old growth, because each of the species is well established and can produce many offspring.
C) Logged, because the disturbed forest affords more resources for increased specific
populations to grow.
D) Logged, because the various populations are stimulated to a higher reproductive potential.
E) Exponential growth is equally probable in old-growth and logged forests.

As N approaches K for a certain population, which of the following is predicted by the
logistic equation?
A) The growth rate will not change.
B) The growth rate will approach zero.
C) The population will show an Allee effect.
D) The population will increase exponentially.
E) The carrying capacity of the environment will increase.

In models of logistic population growth,
A) the population growth rate slows dramatically as N approaches K.
B) new individuals are added to the population most rapidly at the beginning of the population's
growth.
C) new individuals are added to the population as N approaches K.
D) only density-dependent factors affect the rate of population growth.
E) carrying capacity is never reached.

Carrying capacity is
A) seldom reached by marine producers and consumers because of the vast resources of the
ocean.
B) the maximum population size that a particular environment can support.
C) fixed for most species over most of their range most of the time.
D) determined by density and dispersion data.
E) the term used to describe the stress a population undergoes due to limited resources.

Which of the following causes populations to shift most quickly from an exponential to a
logistic population growth?
A) increased birth rate
B) removal of predators
C) decreased death rate
D) competition for resources
E) favorable climatic conditions

Often the growth cycle of one population has an effect on the cycle of another. As moose
populations increase, for example, wolf populations also increase. Thus, if we are considering
the logistic equation for the wolf population,
dN/dt = rN ,
which of the factors accounts for the effect of the moose population?
A) r
B) N
C) rN
D) K
E) dt

Natural selection involves energetic trade-offs between
A) choosing how many offspring to produce over the course of a lifetime and how long to live.
B) producing large numbers of gametes when employing internal fertilization versus fewer
numbers of gametes when employing external fertilization.
C) the emigration of individuals when they are no longer reproductively capable or committing
suicide.
D) increasing the number of individuals produced during each reproductive episode with a
corresponding decrease in parental care.
E) high survival rates of offspring and the cost of parental care.

The three basic variables that make up the life history of an organism are
A) life expectancy, birth rate, and death rate.
B) number of reproductive females in the population, age structure of the population, and life
expectancy.
C) age when reproduction begins, how often reproduction occurs, and how many offspring are
produced per reproductive episode.
D) how often reproduction occurs, life expectancy of females in the population, and number of
offspring per reproductive episode.
E) the number of reproductive females in the population, how often reproduction occurs, and
death rate.

Which of the following pairs of reproductive strategies is consistent with energetic trade-off
and reproductive success?
A) Pioneer species of plants produce many very small, highly airborne seeds, whereas large
elephants that are very good parents produce many offspring.
B) Female rabbits that suffer high predation rates may produce several litters per breeding
season, and coconuts produce few fruits, but most survive when they encounter proper growing
conditions.
C) Species that have to broadcast to distant habitats tend to produce seeds with heavy protective
seed coats, and animals that are caring parents produce fewer offspring with lower infant
mortality.
D) Free-living insects lay thousands of eggs and provide no parental care, whereas flowers take
good care of their seeds until they are ready to germinate.
E) Some mammals will not reproduce when environmental resources are low so they can survive
until conditions get better, and plants that produce many small seeds are likely found in stable
environments.

Pacific salmon and annual plants are excellent examples of
A) cohort disintegration.
B) dispersion.
C) the Allee effect.
D) iteroparous reproduction.
E) semelparous reproduction.

Which of the following is characteristic of K-selected populations?
A) offspring with good chances of survival
B) many offspring per reproductive episode
C) small offspring
D) a high intrinsic rate of increase
E) early parental reproduction