Chapter 46
Student: _________________________________________________________
1. The distribution of individuals in a population is often related to:
A. limiting factors
B. water
C. food
D. all of the choices affect distribution
2. A cohort is:
A. all the individuals in a population born at the same time.
B. all the individuals in a population at the same life stage.
C. all the individuals in a population of reproductive age.
D. all of these choices apply.
3. Which of these would limit exponential growth of a population displaying biotic potential?
A. abiotic factors
B. biotic factors
C. environmental resistance
D. all of these choices will limit exponential growth
4. Ecology is best defined as the study of
A. populations.
B. the rate of population changes.
C. population increases and decreases.
D. how populations are restricted by environmental resistance.
E. organisms as they interact with other organisms and with their physical surroundings.
5. Ecology is derived from the Greek root words for "the study of _______"
A. populations.
B. weather.
C. change.
D. the environment.
E. house or home.
6. The location where an organism lives is best described as the organism's
A. life zone.
B. niche.
C. ecosystem.
D. community.
E. habitat.
7. Your front yard represents a(n) _______ while the leafhoppers represent a(n) ______.
A. population; community
B. population; ecosystem
C. ecosystem; population
D. community; population
E. ecosystem; community
8. When we study the full assortment of organisms in an area as well as the abiotic environment that affects
them, we are studying the
A. populations.
B. niche.
C. ecosystem.
D. community.
E. habitat.
9. The number of individuals per unit area or volume is the
A. population density.
B. population distribution.
C. carrying capacity.
D. rate of natural increase.
E. limiting factor.
10. The pattern of dispersal of individuals within an area is the
A. population density.
B. population distribution.
C. carrying capacity.
D. rate of natural increase.
E. limiting factor.
11. The common patterns of dispersion of individuals of populations are
A. random and orderly.
B. predictable or chaotic.
C. limiting or non-limiting.
D. r or K.
E. uniform, random or clumped.
12. The factor(s) that determine(s) if an organism can live in an area is/are
A. population density.
B. population distribution.
C. carrying capacity.
D. rate of natural increase.
E. limiting factors.
13. Consider that a species of salmon lays 20,000 eggs per pair when it spawns and dies. At the end of five
years, an average of one pair of mature salmon from this group of hatched eggs returns again to spawn in the
parent stream (19,998 have died). What is the rate of natural increase?
A. 10,000, because there were that many eggs produced per parent fish (r)
B. 2,000, because this must be divided by five years
C. zero, because there is exact replacement of the previous generation
D. 2,000, because there was this much average die-off per year
E. 19,998, because there was this much total loss
14. When the number of births exceeds the number of deaths, this results in
A. population growth.
B. biotic potential.
C. environmental resistance.
D. carrying capacity.
15. When the number of births equals the number of deaths, this results in
A. population growth.
B. biotic potential.
C. environmental resistance.
D. carrying capacity.
E. zero population growth.
16. Biological growth rate would be negative when
A. birthrate is greater than death rate.
B. death rate is greater than birth rate.
C. all couples are married but average fewer than two children apiece.
D. a country becomes poorer, because it is related to economic growth.
E. better health care reduces the death rate and increases survivorship of newborns.
17. The maximum rate of natural increase of a population that can occur under ideal conditions is the
A. population growth.
B. biotic potential.
C. environmental resistance.
D. carrying capacity.
18. Population size is believed to level off at the _______ of an environment.
A. population growth
B. biotic potential
C. environmental resistance
D. carrying capacity
19. The carrying capacity of the environment for a species is determined by
A. the reproductive rate of the organism.
B. the number of organisms of that species.
C. the state and national wildlife laws pertaining to that species.
D. a complex ''balance of nature'' that remains to be explained in terms that scientists can calculate.
E. the limited productivity of the environment and the environmental resistance to the biotic potential of the
organism.
20. In the text discussion of r and K selection, an animal is either r-selected or K-selected or somewhere along
an intermediate point between the two. Why can't we design an animal that is both big and fierce and highly
reproductive so it leaves many offspring?
A. Most animals are both r and K selected.
B. There is no limitation; such an animal could evolve.
C. It is structurally impossible for a large animal to have many young.
D. You can "'spend'' your energy to be an active specialist K-selected organism, to produce many offspring as
an r-selected organism, or to be somewhere in between, but you can't spend the energy twice to be both.
21. Optimal circumstances for population growth include all EXCEPT
A. access to mates.
B. high predation levels.
C. low rates of parasitism.
D. unlimited access to food and water.
E. sufficient room for each individual in the population.
22. Biotic potential depends on all of the following EXCEPT
A. the usual number of offspring per reproduction.
B. how often each individual reproduces.
C. how many different mates each individual has.
D. chances of survival until the age of reproduction.
E. the age at which reproduction begins.
23. A species that is limited in size primarily by density-independent effects so that it produces large numbers
of offspring is called
A. a K-strategist.
B. an r-strategist.
C. neither, but it has characteristics of both.
24. As the carrying capacity of an environment is reached by a population,
A. births begin to exceed deaths.
B. deaths begin to exceed births.
C. the rate of reproduction increases.
D. population growth begins to be exponential.
E. density-dependent environmental resistance increases.
25. A population age structure in which the birthrate is high and the population is mainly young would be best
represented by a graph with a/an ______-shaped curve.
A. bell
B. urn
C. pyramid
D. S
E. J
26. A population age structure in which the birthrate is less than the death rate and the postreproductive group is
the largest would be best represented by a graph with a/an ______-shaped curve.
A. bell
B. urn
C. pyramid
D. S
E. J
27. Which of the following describes a type I survivorship curve (drawn by plotting the number of individuals
in a given population alive at the beginning of each age interval)?
A. Most individuals die of old age.
B. Many individuals die early in life.
C. Individuals die at a constant rate throughout time.
D. Most individuals die during their reproductive years.
28. Which of the following describes a type II survivorship curve (drawn by plotting the number of individuals
in a given population alive at the beginning of each age interval)?
A. Most individuals die of old age.
B. Many individuals die early in life.
C. Individuals die at a constant rate throughout time.
D. Most individuals die during their reproductive years.
29. Which of the following describes a type III survivorship curve (drawn by plotting the number of individuals
in a given population alive at the beginning of each age interval)?
A. Most individuals die of old age.
B. Many individuals die early in life.
C. Individuals die at a constant rate throughout time.
D. Most individuals die during their reproductive years.
30. Consider the life of the praying mantis. The large predatory female lays several hundred eggs in a foam
mass in the fall. The young are most vulnerable when they emerge in the spring, but the few that survive spread
out over the countryside and, if they find a mate, lay eggs the following fall. Which type of survivorship curve
does this represent?
A. type I
B. type II
C. type III
D. exponential growth followed by a decline from resource depletion
E. maximal exponential growth and minimal use of carrying capacity
31. Farmers sprayed leechi trees to suppress populations of scale insects. This also killed the populations of a
predatory lacewing that controlled the numbers of scales. Soon the spraying did no good, and the damage to the
leechi from the scales was greater than before spraying had occurred. Few predatory lacewings exist in the trees
now because
A. they, too, are insects so they are r-selected.
B. both insects were K-selected and resistance was a matter of chance.
C. the predator was r-selected and was therefore more susceptible to the spray.
D. the scale insect was r-selected and the high number of young included a resistant strain; the predator was Kselected and will take longer to produce a resistant variety.
32. An equilibrium species, such as an oak tree or a whale, with small numbers of offspring, have a/an ______shaped growth curve.
A. bell
B. urn
C. pyramid
D. S
E. J
33. The near future of the world population is most likely to involve
A. an even slowing down of all population growth everywhere due to universal reproductive factors.
B. a slowing down of population growth in poor countries where they cannot afford to support children, but
higher growth in richer countries.
C. a lowering of growth in richer countries but continued growth in poorer countries.
D. a continuation of human population growth at the same pace as in the previous century.
34. The sequence of decreased death rate followed by a decrease in birthrate is called _______.
A. environmental resistance.
B. a limiting factor.
C. doubling time coefficient.
D. demographic transition.
E. replacement reproduction.
35. Age structure diagrams with a broad base suggest that
A. environmental resistance is not at work.
B. the individuals must be larger than usual.
C. the biotic potential must be larger than usual.
D. the population will continue to grow for some time.
E. All of the choices are true.
36. If all couples have just two children, will this result in zero population growth?
A. Yes since the math is simple replacement reproduction or two replacing two.
B. Yes since two much older parents will be dying on average as each of the two children are born.
C. No because no one is dying in the population.
D. No because the life expectancy is gradually lengthening and because many countries have more young
women entering reproductive age than leaving it.
37. A population with rapidly expanding exponential growth would be best represented by a graph with a/an
______-shaped curve.
A. bell
B. urn
C. pyramid
D. S
E. J
38. In the growth curve formula, when N is very large, (K-N)/N is almost equal to 0 and results in
A. the population growing as fast as it can, or r(N).
B. the population leveling off near carrying capacity.
C. the population exceeding carrying capacity; more are dying due to starvation than are born.
D. You can't tell without knowing the value of r (rate of reproduction).
39. With nearly 1,200,000,000 people but less land to farm than the U.S., the People's Republic of China
maintains a one-child-per-family policy. Compared to the historical potential, this changed which numerical
value in the full growth equation?
A. r
B. K
C. N
D. cannot determine without more information
40. Of the following which is NOT included in the area evaluated by a population ecologist?
A. distribution of organisms
B. organism abundance
C. related statistics to the species' life history with regard to population increase and decrease
D. evaluation of coevolution of community dynamics
41. All of the populations interacting at a locale are
A. an ecosystem
B. the community
C. the biosphere
D. All of the choices are true.
42. Abiotic factors affecting the distribution of organisms includes all of the following EXCEPT
A. precipitation.
B. daily and seasonal temperature variations.
C. particular nutrient concentrations.
D. food source presence.
43. In the discrete pattern of population growth
A. members of a population breed just once.
B. the mature adult ceases to grow.
C. is a pattern found in insects and annual plants.
D. All of the choices are true.
44. In the continuous pattern of population growth
A. many reproductive events occur throughout an organism's lifetime.
B. individuals invest energy in the organism's future survival.
C. vertebrates, shrubs, and trees reproduce in this manner.
D. All of the choices are true.
45. In the environmental factor regulation of population size in natural environments density independent
factors include which of the following?
A. weather
B. natural disasters
C. geographical barriers
D. all of the choices
46. Competition is a positive relationship between individuals.
True False
47. Other factors such as behavior and physiology may affect growth rates of a population.
True False
48. No matter what the conditions, a species with low biotic potential will always have a low population size.
True False
49. A population of food resources for humans should be harvested only to the point where maximal population
growth occurs(the inflection point of the growth curve).
True False
50. Density-dependent environmental resistance produces more pressure on a small population than on a large
population.
True False
51. Survivorship is the number of individuals in a population alive at the beginning of each age interval.
True False
52. Dandelions and tent caterpillars are examples of opportunistic species that tend to move in high numbers
and rapidly occupy new environments, and they are said to be r-strategists.
True False
53. Most species are intermediate between r-strategists and K-strategists, and tend to have a type II survivorship
curve.
True False
54. An r-selected species has been evolutionarily selected for equilibrium in a specialized environment, and it
has a stable population size when undisturbed.
True False
55. Wild fluctuations in population size is termed chaos.
True False
56. Parasitism, competition, and predation are density independent factors of population size control.
True False
57. When number of births + immigration exceeds number of deaths + emigration, a population size will
increase.
True False
58. Zero population growth will be achieved as soon as couples have only replacement reproduction, with two
children per couple.
True False
59. Factors that oppose biotic potential characterize environmental resistance.
True False
60. Discuss the circumstances under which the biotic potential of a population might be reached, and why these
conditions are usually not met.
61. Explain the population differences between an r-selected species and a K-selected species.
62. In Taiwan, two mites are found on rice plants. One mite feeds on the rice plant and produces a huge number
of young. The second mite is larger and is predatory on the rice mite, but like most predators, produces fewer
young. The field is sprayed with a broad spectrum insecticide that kills both mites. However, with no further
spraying, the rice is far more seriously infested with mites the next few years than before the spraying. Why?
63. Explain why changing the environment may work better to rid pests than killing them with pesticides.
64. Define the age groups within a population.
65. Define the kinds of survivorship curves a population may have, and discuss which would be most common
in humans under optimal conditions.
66. Discuss how population growth continues even after replacement reproduction has been achieved.
67. In spite of the fact that in China the birthrate has dropped countrywide (although not in rural areas) to an
average of fewer than two children per couple, the Chinese population will still increase for the next decade.
Why?
Chapter 46 KEY
1. D
2. D
3. D
4. E
5. E
6. E
7. D
8. C
9. A
10. B
11. E
12. E
13. C
14. A
15. E
16. B
17. B
18. D
19. E
20. D
21. B
22. C
23. B
24. E
25. C
26. B
27. A
28. C
29. B
30. C
31. D
32. D
33. C
34. D
35. D
36. D
37. E
38. B
39. A
40. D
41. B
42. D
43. D
44. D
45. D
46. FALSE
47. TRUE
48. FALSE
49. TRUE
50. FALSE
51. TRUE
52. TRUE
53. TRUE
54. FALSE
55. TRUE
56. FALSE
57. TRUE
58. FALSE
59. TRUE
60. Answers will vary.
61. Answers will vary.
62. Answers will vary.
63. Answers will vary.
64. Answers will vary.
65. Answers will vary.
66. Answers will vary.
67. Answers will vary.