53, BSC108 test 4 MB questions and answers, Bio
Final HW questions And answers, Biology Exam 2
and answers, Biology 1407
1) Population ecologists are primarily interested in
A) studying interactions among populations of organisms that inhabit the same area.
B) understanding how biotic and abiotic factors influence the density, distribution,
size, and age structure of populations.
C) how humans affect the size of wild populations of organisms.
D) how populations evolve as natural selection acts on heritable variations among
individuals and changes in gene frequency.
E) the overall vitality of a population of organisms.✔✔B
2) 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✔✔C
3) 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✔✔A
4) During the spring, you are studying the mice that live in a field near your home.
The population density is high, but you realize that you rarely observe any
reproductive female mice. This most likely indicates
A) that there is selective predation on female mice.
B) that female mice die before reproducing.
C) that this habitat is a good place for mice to reproduce.
D) that you are observing immigrant mice.
E) that the breeding season is over.✔✔D
5) 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.✔✔D
6) 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 tree
D) moths, in a city at night
E) lake trout, which seek out cold, deep water high in dissolved oxygen✔✔A
7) 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.✔✔C
8) 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) multiplying the number of moss plants counted in 10 quadrats of 1m2 each by
100 to determine the density per kilometer2.
E) counting the number of zebras from airplane census observations.✔✔E
9) 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 the 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.
A) I only
B) II only
C) I and II only
D) II and III only
E) I, II, and III✔✔E
10) 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.✔✔C
11) Which of the following sets of measurements is the most useful when studying
populations?
A) density, dispersion, and demographics of a population
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✔✔A
12) 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 x 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.✔✔B
13) Which of the following is the best 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✔✔C
14) 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✔✔E
15) 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✔✔D
16) 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.✔✔C
17) Which of the following is the most important assumption for the capture-
recapture method to estimate the size of wildlife populations?
A) All females in the population have the same litter size.
B) More individuals emigrate from, as opposed to immigrate into, a population.
C) Over 50% of the marked individuals need to be trapped during the recapture
phase.
D) There is a 50:50 ratio of males to females in the population before and after
trapping and recapture.
E) Marked individuals have the same probability of being recaptured as unmarked
individuals during the recapture phase.✔✔E
18) 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✔✔B
19) Exponential growth of a population is represented by dN/dt =
A)
B) rN
C) rN (K + N)
D) rN
E) rN✔✔B
20) 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) 6
B) 18
C) 128
D) 512
E) 1,024✔✔D
Final HW questions And answers, Biology Exam 2
and answers, Biology 1407
1) Population ecologists are primarily interested in
A) studying interactions among populations of organisms that inhabit the same area.
B) understanding how biotic and abiotic factors influence the density, distribution,
size, and age structure of populations.
C) how humans affect the size of wild populations of organisms.
D) how populations evolve as natural selection acts on heritable variations among
individuals and changes in gene frequency.
E) the overall vitality of a population of organisms.✔✔B
2) 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✔✔C
3) 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✔✔A
4) During the spring, you are studying the mice that live in a field near your home.
The population density is high, but you realize that you rarely observe any
reproductive female mice. This most likely indicates
A) that there is selective predation on female mice.
B) that female mice die before reproducing.
C) that this habitat is a good place for mice to reproduce.
D) that you are observing immigrant mice.
E) that the breeding season is over.✔✔D
5) 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.✔✔D
6) 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 tree
D) moths, in a city at night
E) lake trout, which seek out cold, deep water high in dissolved oxygen✔✔A
7) 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.✔✔C
8) 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) multiplying the number of moss plants counted in 10 quadrats of 1m2 each by
100 to determine the density per kilometer2.
E) counting the number of zebras from airplane census observations.✔✔E
9) 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 the 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.
A) I only
B) II only
C) I and II only
D) II and III only
E) I, II, and III✔✔E
10) 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.✔✔C
11) Which of the following sets of measurements is the most useful when studying
populations?
A) density, dispersion, and demographics of a population
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✔✔A
12) 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 x 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.✔✔B
13) Which of the following is the best 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✔✔C
14) 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✔✔E
15) 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✔✔D
16) 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.✔✔C
17) Which of the following is the most important assumption for the capture-
recapture method to estimate the size of wildlife populations?
A) All females in the population have the same litter size.
B) More individuals emigrate from, as opposed to immigrate into, a population.
C) Over 50% of the marked individuals need to be trapped during the recapture
phase.
D) There is a 50:50 ratio of males to females in the population before and after
trapping and recapture.
E) Marked individuals have the same probability of being recaptured as unmarked
individuals during the recapture phase.✔✔E
18) 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✔✔B
19) Exponential growth of a population is represented by dN/dt =
A)
B) rN
C) rN (K + N)
D) rN
E) rN✔✔B
20) 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) 6
B) 18
C) 128
D) 512
E) 1,024✔✔D
