PRACTICE POPULATIONS TEST (WITH ANSWERS)
Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
____
____
____
____
____
____
____
____
____
1. The number of organisms of the same species distributed within the usable area of its habitat is best known as
which of the following?
a. population size
d. population density
b. ecological density
e. population dynamics
c. crude density
2. In the grasslands of Western Canada, prairie dogs live in colonies, isolated from other colonies by large,
unoccupied areas of land. This is best described as
a. ecological dispersion
d. clumped dispersion
b. random dispersion
e. uniform dispersion
c. crude density
3. A sampling area used for estimating population size is best known as which of the following?
a. a mark recapture
d. a head count
b. a base line
e. satellite surveillance
c. a quadrat
4. Which of the population dispersion patterns is most often found in natural populations?
a. uniform dispersion
b. clumped dispersion
c. random dispersion
d. all of these patterns are equally common
e. none of the above
5. The maximum number of organisms that can be sustained by available resources over a given period of time
is known as which of the following?
a. ecological load
d. environmental overload
b. carrying capacity
e. none of the above
c. Pop
6. The most accurate method of determining the size of a group of stationary organisms is which of the
following?
a. quadrat sampling
d. counting nests
b. mark-recapture sampling
e. all of the above
c. technological tracking
7. Mark-recapture sampling is a method commonly used to determine the population size of which of the
following?
a. fish
d. small rodents
b. polar bears
e. all of the above
c. migrating ducks
8. Which of the following is not an assumption made when mark-recapture sampling is used?
a. the population size does not change during the sampling study
b. the proportion of marked to unmarked organisms remains constant
c. marking techniques do not harm the organisms
d. marked and unmarked organisms have an equal chance of capture
e. all of these assumptions are made
9. In a population of birds being studied over a limited time period, 4 eggs hatch, 6 birds leave the area, 3 are
eaten by cats, and 5 move into the area. What is the population change over the period of study?
a. an increase of 2 birds
b. an increase of 4 birds
c. a decrease of 4 birds
d. a decrease of 2 birds
e. the population size did not change
____ 10. Under ideal conditions, a population of bacteria can grow to more than 10 in 24 h. This is a statement of the
population's
a. density
d. growth rate
b. carrying capacity
e. logistic growth
c. biotic potential
____ 11. Mice have the ability to produce over a dozen offspring every 3 weeks. This statement describes their
a. fertility
d. birth rate
b. fecundity
e. mating success
c. natality
____ 12. A population with very high mortality rates among the young and very low mortality rates among sexually
mature adults exhibits which of the following?
a. a type I survivorship pattern
d. a type IV survivorship pattern
b. a type II survivorship pattern
e. none of the above
c. a type III survivorship pattern
____ 13. Factors limiting reproductive potential include which of the following?
a. migration
d. food availability
b. disease
e. all of the above
c. mating success
____ 14. The following equation:
[(births + immigration) (deaths + emigration)]100
initial population size
is used to calculate
a. population change
d. exponential growth rate
b. growth rate
e. all of the above
c. geometric expansion
____ 15. A population whose growth is influenced by natality, mortality and migrations is described as which of the
following?
a. endangered
d. geometric
b. open
e. exponential
c. closed
____ 16. The following mathematical expression:
N(t + 1)
N(t)
can be used to determine
a. biotic potential
d. maximum population size
b. geometric growth
e. population density
c. exponential growth
____ 17. A population of groundhogs in a meadow exhibits geometric growth. During the year, the initial population of
100 animals had 45 births and 40 deaths. The geometric growth rate is closest to which of the following?
a. 1.45
d. 1.05
b. 0.95
e. 5
c. 105
____ 18. The time it takes a population to double in size can be estimated by the expression
a.
b.
c. rN
d.
e. none of these can estimate doubling time
____ 19. The following mathematical expression:
____ 20.
____ 21.
____ 22.
____ 23.
____ 24.
____ 25.
____ 26.
____ 27.
can be used to estimate population
a. size
d. biotic potential
b. doubling time
e. logistical growth rate
c. growth rate
A smooth curve showing the long-term exponential growth of a population is usually which of the following?
a. a straight line
d. negatively sloped
b. a J-shaped curve
e. none of the above
c. an S-shaped curve
In natural populations, exponential growth does not continue indefinitely because of limited amount(s) of
which of the following?
a. energy
d. space
b. water
e. all of the above
c. shelter
The mathematical expression rmaxN  [(K – N) / K] can be used to calculate which of the following?
a. population size
d. geometric growth rate
b. instantaneous growth rate
e. exponential growth rate
c. logistic maximum
Termites eat wood, but cannot digest cellulose. In their gut live a protist that can digest cellulose, but is
unable to survive outside the termite. If the protists are removed, the termite will starve. This is an example of
which of the following?
a. parasitism
d. resource partitioning
b. obligatory mutualism
e. none of the above
c. commensalism
Organisms introduced into a region that is not their natural habitat and in which they have few natural
predators are known to ecologists as which of the following?
a. exotics
d. nonindigenous species
b. predators
e. both a and d
c. accidents
The change from a hunter-gatherer lifestyle to its present form can be explained by
a. climate change
d. psychology
b. domestication
e. disease
c. family planning
Which population-determining factors had the greatest effect on limiting the growth of early humans?
a. low birth rate
d. a and b only
b. high death rate
e. a, b, and c
c. high rate of emigration
A nomadic lifestyle has the greatest effect on which of the following?
a. birth rate
d. emigration
____ 28.
____ 29.
____ 30.
____ 31.
____ 32.
____ 33.
____ 34.
____ 35.
____ 36.
b. death rate
e. none of these is affected
c. immigration
Which of the following is not a result of the Industrial Revolution?
a. increased food supply
b. higher percentage of farming
c. increase in carrying capacity of the Earth
d. lower percentage of people farming
e. decline in death rate
A population pyramid with a very broad base that curves sharply upward indicates which of the following?
a. negative growth
d. rapid growth
b. zero growth
e. an even population distribution
c. slow growth
A population pyramid showing rapid growth
a. has a narrow base, and bulges as it extends upward
b. shows an even age distribution for many decades
c. narrows steadily from its base upward
d. has a broad base and curves sharply upward
e. has a narrow base and gradually widens
A population pyramid that slopes steadily upward indicates which of the following?
a. negative growth
d. rapid growth
b. zero growth
e. an even population distribution
c. slow growth
A population pyramid showing slow growth
a. has a narrow base, and bulges as it extends upward
b. shows an even age distribution for many decades
c. narrows gradually from its base upward
d. has a broad base and curves sharply upward
e. has a narrow base and gradually widens
A population pyramid that shows an even age distribution for many decades indicates which of the following?
a. negative growth
d. rapid growth
b. zero growth
e. none of the above
c. slow growth
A population pyramid indicating zero growth
a. has a narrow base, and bulges as it extends upward
b. shows an even age distribution for many decades
c. narrows steadily from its base upward
d. has a broad base and curves sharply upward
e. has a narrow base and gradually widens
A population pyramid having a narrow base, which bulges outwards as age increases, indicates which of the
following?
a. negative growth
d. rapid growth
b. zero growth
e. none of the above
c. slow growth
A population showing negative growth
a. has a narrow base, and bulges as it extends upward
b. shows an even age distribution for many decades
c. narrows steadily from its base upward
d. has a broad base and curves sharply upward
e. has a narrow base and gradually widens
____ 37. Increased agricultural use of appropriate regions of the world lead to which of the following?
a. increased human birth rate
d. all of the above
b. increased human migration
e. a and c only
c. decreased human death rate
____ 38. If population growth continues, it would degrade which of the following factors determining Earth's carrying
capacity?
a. food production
b. land use
c. water quality
d. availability of non-renewable resources
e. all of the above
Completion
Complete each sentence or statement.
39. When using mark-recapture sampling, an ecologist determines the number of marked individuals in the
original sample (M), the number of organisms recaptured (n), and the number of marked organisms in the
recaptured group (m).
Using these variables, the total population N
____________________
40. Population growth can be expressed in terms of initial population size (n), immigration (i), emigration (e),
mortality (d), and natality (b). Using these variables,
population growth = ____________________.
41. If the number of surviving organisms in an endangered population falls below the number needed to cope
with variations in the environment, the population may not survive. This demonstrates the
________________________________________.
42. Similar species are able to reduce competition by occupying different nonoverlapping niches. This is known
as ______________________________.
43. In many ways, a science classroom can be considered a model of an ecosystem. The students rely on the
teacher for knowledge and guidance; the teacher would not have a job without the students. Neither can exist
without the other. Ecologically, this relationship demonstrates ____________________.
44. Exotic species, such as the Zebra mussel, often disrupt the ecology of the area into which they have been
introduced because they have ______________________________.
Matching
There are many mathematical equations used in the study of populations. Match the factor being calculated
with the most appropriate expression.
a. percent population change
b. geometric growth rate
c. instantaneous growth rate (exponential)
d. growth rate at a given time (logistic)
e. doubling time
____ 45. maximum intrinsic growth rate  population size  (carrying capacity – population size./carrying capacity
____ 46. population size in next year-population size in present year
____ 47. 0.69/growth rate per capita
____ 48. [(births immigration) – (deaths + emigration)]/initial population  100
____ 49. growth rate per capita  population size
Match the word or phrase with its best definition.
a. carrying capacity
d. fecundity
b. biotic potential
e. emigration
c. immigration
____
____
____
____
____
50.
51.
52.
53.
54.
potential of a species to produce large number of offspring in a lifetime
intrinsic rate of natural increase
maximum number of organisms that can be sustained by the available resources
number of individuals that move away from an existing population
number of individuals that move into an existing population
Population determining factors are said to be either density-dependent, or density-independent. Match each
factor with the appropriate dependency.
a. density-dependent
b. density-independent
____
____
____
____
____
____
____
55.
56.
57.
58.
59.
60.
61.
human intervention (e.g., pesticide application)
extreme weather
the Allee effect
intraspecific competition
predation
disease
environmental changes
Ecology studies the relationships between members of a community. Match the relationship with the best
description of the effects of the relationship on those involved.
a. intraspecific competition
d. parasitism
b. interspecific competition
e. mutualism
c. predation
f. commensalism
____
____
____
____
____
____
62.
63.
64.
65.
66.
67.
beneficial to one; usually lethal to the other
detrimental to both, and the species in general
beneficial to one; the other is unaffected
beneficial to both
detrimental to one or both populations
beneficial to one; harmful, but not usually fatal to the other
Short Answer
68. Define the term population as it is used by ecologists.
69. Explain why a population may show clumped dispersion.
70. Write the equation used to calculate the population change of an open population.
71. Write the equation used to calculate the population change of a closed population.
72. Describe the technique of population known as "mark-recapture."
73. What are three important assumptions that are made when a mark-recapture study is done?
74. Explain the difference between fertility and fecundity.
75. Define the term "biotic potential". What general name is applied to an essential resource that is in short supply
or unavailable, and prevents an organism from achieving this potential?
76. Distinguish between the terms "habitat" and "niche".
77. Explain the concept of "resource partitioning," and explain how it may increase the chance of species success.
78. Prey species often develop passive defense mechanisms that reduce the chance of them being eaten. List three
types of passive defence mechanisms.
79. Define the term "commensalism" and explain why some biologists argue that it does not exist.
80. Briefly explain why a change from a hunter-gatherer lifestyle allowed the early human population to increase.
81. The Industrial Revolution started a series of changes that are still affecting people. What were the two most
immediate effects in the 18th century?
82. Epidemic diseases were not a serious problem to hunter-gatherer societies. It was only when agriculture was
adopted did these become a significant factor in human populations. Explain this statement.
Problem
83. A lawn-care company wishes to estimate the density of a weed population in a park before spraying. The park
measures 100 m  50 m. The technician randomly places four 1.0 m  0.5 m quadrats in the park, and finds
weed counts of 11, 23, 16 and 20 plants in the 4 quadrats. Estimate the density of the population. A formal
solution is required.
84. In a river in Ontario, 270 Atlantic salmon were captured and fin-marked with a numbered T-bar anchor tag.
Two weeks later, a total of 112 Atlantic salmon were recaptured, and 11 carried the T-bar anchor tags.
Estimate the Atlantic salmon population in this river during this study.
85. Each May, harp seals give birth on pack ice off the coast of Newfoundland and Labrador. In a hypothetical
situation, an initial population of 1500 seals gives birth to 680 pups, and during the next 12 months, 90 seals
die. Assuming that the population is growing geometrically, what will the harp seal population be in 11 years?
A formal solution is required.
86. During the summer, a population of aphids exhibits exponential growth on rose bushes. The initial population
of aphids on a rose bush is 53 and their intrinsic rate of increase is 0.281 per day.
Calculate the initial instantaneous growth rate. A formal solution is required.
87. Historical records suggest that in A.D. 1650, the human population was growing such that the population
doubled in 200 years. Determine the intrinsic growth rate of the human population in 1650 as a percent. A
formal solution is required.
88. A population is growing continuously. The carrying capacity of the environment is 800 individuals and the
maximum growth rate is 0.35.
a. Determine the population growth rate if the population size is 20 individuals. A formal solution is
required.
b. How would this rate compare to the rate if the population was very near the carrying capacity? A
calculation is not required.
12 POPULATIONS
Answer Section
MULTIPLE CHOICE
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
COMPLETION
B
D
C
B
B
A
E
E
E
C
B
C
E
A
B
B
D
D
B
B
E
B
B
E
B
D
A
B
D
D
C
C
B
B
A
A
D
E
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
K/U
K/U
I
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
I
I
I
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U
K/U, MC
K/U
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
14.1
14.1
14.1
14.1
14.2
14.1
14.1
14.1
14.2
14.2
14.2
14.2
14.2
14.2
14.2
14.2
14.2
14.2
14.2
14.2
14.2
14.2
14.4
14.4
15.1
14.1, 15.1
15.1
15.1
15.2
15.2
15.2
15.2
15.2
15.2
15.2
15.2
15.1
15.2
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
PD1.02
PD1.02
PD2.02
PD1.02
PD1.02
PD1.02, PD2.01
PD1.01, PD2.01
PD1.01, PD2.01
PD1.02
PD2.01
PD1.02, PD2.01
PD1.02, PD2.01
PD1.02
PD2.01
PD1.02
PD2.01
PD2.01
PD2.01
PD2.01
PD2.01
PD1.02, PD2.01
PD2.01
PD1.01
PD2.03
PD1.05
PD1.02, PD1.05
PD1.05
PD1.05
PD2.01
PD1.06
PD1.06
PD1.06
PD1.06
PD1.06
PD1.06
PD1.06
PD2.04
PD1.06
39. ANS:
Mn
m
REF:
K/U
OBJ: 14.2
40. ANS:
LOC: PD1.02
41. ANS: minimum viable population size
LOC: PD1.01, PD1.03
42. ANS: resource partitioning
LOC: PD1.01
43. ANS: mutualism
LOC: PD1.01
44. ANS:
few natural predators
no natural predators
REF:
LOC: PD1.02
REF: K/U
OBJ: 14.2
REF: K/U
OBJ: 14.3
REF: K/U
OBJ: 14.4
REF: K/U
OBJ: 14.4
K/U
OBJ: 14.4
LOC: PD1.01, PD2.04
MATCHING
45.
46.
47.
48.
49.
ANS:
ANS:
ANS:
ANS:
ANS:
D
B
E
A
C
REF:
REF:
REF:
REF:
REF:
K/U
K/U
K/U
K/U
K/U
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
14.2
14.2
14.2
14.2
14.2
LOC:
LOC:
LOC:
LOC:
LOC:
PD2.01
PD2.01
PD2.01
PD2.01
PD1.02
50.
51.
52.
53.
54.
ANS:
ANS:
ANS:
ANS:
ANS:
E
C
A
E
D
REF:
REF:
REF:
REF:
REF:
K/U
K/U
K/U
K/U
K/U
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
14.2
14.2
14.2
14.2
14.2
LOC:
LOC:
LOC:
LOC:
LOC:
PD1.02, PD1.03
PD1.02
PD1.02, PD1.03
PD1.02
PD1.02
55.
56.
57.
58.
59.
60.
61.
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
B
B
A
A
A
A
B
REF:
REF:
REF:
REF:
REF:
REF:
REF:
K/U
K/U
K/U
K/U
K/U
K/U
K/U
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
OBJ:
14.3
14.3
14.3
14.3
14.3
14.3
14.3
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
LOC:
PD2.04
PD1.02
PD2.01
PD1.01
PD2.03, PD2.04
PD1.01
PD2.04
62.
63.
64.
65.
ANS:
ANS:
ANS:
ANS:
C
A
F
E
REF:
REF:
REF:
REF:
K/U
K/U
K/U
K/U
OBJ:
OBJ:
OBJ:
OBJ:
14.4
14.3
14.2
14.2
LOC:
LOC:
LOC:
LOC:
PD1.01
PD1.01
PD1.01
PD1.01
66. ANS: B
67. ANS: D
REF: K/U
REF: K/U
OBJ: 14.2
OBJ: 14.2
LOC: PD1.01
LOC: PD1.01
SHORT ANSWER
68. ANS:
A population is a group of organisms of the same species living within a particular area (or volume).
REF: K/U
OBJ: 14.1
LOC: PD1.02
69. ANS:
Only some areas of the habitat are favourable for survival, causing organisms to grow/live there.
Social behaviour, such as herding, may also show this distribution.
REF: K/U
70. ANS:
OBJ: 14.1
LOC: PD1.02
REF: K/U
71. ANS:
OBJ: 14.2
LOC: PD1.03
REF: K/U
OBJ: 14.2
LOC: PD1.03
72. ANS:
- specimens of the desired species are collected and marked
- specimens are later collected again
- the number of marked animals in the second sample is noted
REF: K/U
OBJ: 14.1
LOC: PD2.02
73. ANS:
- every organism has an equal chance of being caught
- the ratio of marked to unmarked organisms is constant between marking and recapture
- there is no change in population size between mark and recapture
REF: K/U
OBJ: 14.1
LOC: PD2.02
74. ANS:
- Fecundity: theoretical maximum number of offspring that could be produced by a species in one lifetime
- Fertility: the number of offspring actually produced by an individual during its lifetime, affected by food
supply, disease, mating success, etc.
REF: K/U
OBJ: 14.2
LOC: PD1.02, PD2.01
75. ANS:
- maximum reproductive rate under ideal conditions (or, intrinsic rate of natural increase)
- limiting factor
REF: K/U
76. ANS:
OBJ: 14.2, 14.3
LOC: PD1.03, PD2.01
- Habitat: the food, water, shelter and space requirements determining where an organism lives, its "address"
- Niche: the role of the organism in its environment; where it lives, and how it "fits in" to the community
structure, its "job"
REF: K/U
OBJ: 14.4
LOC: PD1.01
77. ANS:
- the occupying of non-overlapping niches by organisms requiring similar resources
- reduces competition, making resources available
REF: K/U
OBJ: 14.4
LOC: PD1.02
78. ANS:
Any 3 of-morphological (e.g., spines, hooks, needles, etc.)
- chemical ( taste, toxic, smell, etc.)
- camouflage
- hiding
- mimicking dangerous species
REF: K/U
OBJ: 14.4
LOC: PD1.01
79. ANS:
- a relationship in which one organism benefits, and the other is unaffected
- very difficult to determine if "unaffected" species benefits, is harmed or is truly not affected without direct
observation
REF: K/U
OBJ: 14.4
LOC: PD1.01
80. ANS:
- hunter-gathers have low birth rates, high death rates ,especially among very young, limiting growth
- agriculture allowed for a more reliable food supply, and nonmigratory lifestyle allowed survival of young,
leading to growth
REF: K/U
OBJ: 15.1
LOC: PD1.05, PD2.04
81. ANS:
- increase in food supply, which resulted in an increase in population
- fewer people needed to work the land, which resulted in more urbanization
REF: K/U
OBJ: 15.1
LOC: PD1.05
82. ANS:
- epidemics diseases develop (evolve) where population densities are high
- agriculture led to increased densities as people settled in farming communities
REF:
PROBLEM
83. ANS:
K/U, MC
OBJ: 15.1
LOC: PD1.05
The density of the weed population is 35 weeds/m
REF: I
84. ANS:
OBJ: 14.1
LOC: PD2.02
The river held 2749 Atlantic salmon during the 2-week study.
REF: K/U
OBJ: 14.1
LOC: PD1.02
85. ANS:
In year 1, the population change
= births deaths
= 680 seals 90 seals
= 590 seals
Initial population, N(0) = 1500 seals
Population at end of year 1, N(1)
= 1500 seals 590 seals
= 2090 seals
Geometric growth rate = N(t+1) = 2090 = 1.4
N(t) 1500
N(0) = 1500 seals, Geometric growth Rate = 1.4, t = 11 a
N(11) = N(0)  (Geometric Growth Rate.11
1500  (1.4)11)
= 1500  40.5
= 60 743
With the same growth rate, the seal population will have reached 60 743 at the end
of 11 years.
REF: K/U
OBJ: 14.2
86. ANS:
r = 0.281/h and N = 53 aphids
dN = rN
dt
= 0.281/h  53 aphids
LOC: PD2.01
= 14.89 aphids/h
= 15 aphids/h
The aphid population has an initial instantaneous growth rate of 15 aphids/h.
REF: K/U
87. ANS:
OBJ: 14.2
LOC: PD2.01
The growth rate of the human population in 1650 was 0.34%.
REF: K/U
OBJ: 14.2, 15.1
88. ANS:
a.
rmax = 0.35
N = 20
K = 800
dN/dt = rmaxN[(K N)/K]
= 0.35  20  [(800 20)/800]
= 0.35  20  0.975
= 6.8
LOC: PD2.01, PD2.04
The population growth rate is 6.8 when the population has 20 individuals.
b. Nearing the carrying capacity, the rate would be declining/approaching zero.
REF:
K/U
OBJ: 14.2
LOC: PD2.01