Ch.53 Flashcards


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1
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In the figure, which of the following survivorship curves implies that an animal may lay many eggs, of which a regular number die each year on a logarithmic scale?
A) curve A
B) curve B

C) curve C
D) curves A or C

B) curve B

2
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In the figure, which of the following survivorship curves most applies to humans living in developed countries?
A) curve A
B) curve B

C) curve C
D) curve A or curve B

A) curve A

3
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Using the table, how would you describe the population dynamics of the Eurasian lizard, Z. vivipara?
A) The population is increasing.
B) The population is decreasing.

C) The population is stable.
D) The table does not provide this information.

A) The population is increasing.

4
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Using the table, determine which age class year would cause the largest decline in the resulting population growth, if it were wiped out by disease.
A) age class year 1
B) age class year 2

C) age class year 3
D) age class year 4

A) age class year 1

5

Suppose researchers marked 800 turtles and later were able to trap a total of 300 individuals in that population, of which 150 were marked. What is the estimate for total population size?
A) 200
B) 1,050

C) 1,600 D) 2,100

C) 1,600

6
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Looking at the figure, what factor is contributing significantly to stabilizing the population size over time?

  1. I) no migration
  2. II) low migration
  3. III) high migration

A) only I
B) only II
C) only III
D) only II and III

C) only III

7

Which of the following assumptions must be made regarding the mark-recapture estimate of population size?

  1. I) Marked and unmarked individuals have the same probability of being trapped.
  2. II) The marked individuals have thoroughly mixed with the population after being marked.
  3. 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) I, II, and III

D) I, II, and III

8

Which of the following is the most important assumption for the mark-recapture method to estimate the size of wildlife populations?
A) More individuals emigrate from, as opposed to immigrate into, a population.
B) Over 50% of the marked individuals were trapped during the recapture phase.

C) There is a 50:50 ratio of males to females in the population before and after trapping and recapture.
D) Marked individuals have the same probability of being recaptured as unmarked individuals during the recapture phase.

D) Marked individuals have the same probability of being recaptured as unmarked individuals during the recapture phase.

9
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Which curve best describes survivorship in marine mollusks? A) A
B) B
C) C

D) E

D) E

10
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Which curve best describes survivorship in elephants? A) A
B) B
C) C

D) E

A) A

11

To measure the population of lake trout in a 250-hectare lake, 400 individual trout were netted and marked with a fin clip, then returned to the lake. The next week, the lake was netted again, and out of the 200 lake trout that were caught, 50 had fin clips. Using the mark-recapture estimate, the lake trout population size could be closest to which of the following?
A) 200
B) 400
C) 1,600
D) 80,000

C) 1,600

12

Long-term studies of Belding's ground squirrels show that immigrants move nearly 2 kilometers 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) These immigrants provide a source of genetic diversity for the other populations.
C) Those individuals that emigrate to these new populations are looking for less crowded conditions with more resources.
D) Gradually, the populations of ground squirrels will move from a clumped to a uniform population pattern of dispersion.
Answer: B

B) These immigrants provide a source of genetic diversity for the other populations.

13
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In the accompanying life table of a hypothetical population, what are the missing values for lx (y and z)? lx = the proportion alive at the start of year (age specific survivorship rate).
A) y = 0.5, z = 0.5
B) y = 1.0, z = 0.5

C) y = 0.5, z = 0.1
D) y = 1.0, z = 0.2

C) y = 0.5, z = 0.1

14

An ecologist recorded 12 white-tailed deer, Odocoileus virginianus, per square kilometer (km2) in one woodlot and 20 km2 in another woodlot. What was the ecologist comparing? A) density
B) dispersion

C) carrying capacity
D) range

A) density

15

Uniform spacing patterns in plants such as the creosote bush are most often associated with ________.
A) patterns of high humidity
B) the random distribution of seeds

C) competitive interaction between individuals of the same population D) the concentration of nutrients within the population's range

C) competitive interaction between individuals of the same population

16

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) lake trout, which seek out cold, deep water high in dissolved oxygen

A) red squirrels, who actively defend territories

17

Which of the following examples would most accurately measure the dispersion of a population being studied?
A) counting the number of times a one-kilometer transect is intersected by tracks of red squirrels after a snowfall
B) measuring the distance between several burrows within a large prairie dog colony in a

Age (years) x

Number alive at start of year nx

lx

1

100

1.0

2

50

0.5

3

50

y

4

10

z

grassland
C) measuring the average distance between individuals and their nearest neighbor, and then analyzing the variation and comparing those measurements at larger scales
D) counting the number of zebras from airplane census observations

C) measuring the average distance between individuals and their nearest neighbor, and then analyzing the variation and comparing those measurements at larger scales

18

Which of the following is the best natural example of a uniform pattern of dispersion? A) bees collecting pollen in a wildflower meadow
B) moss spores floating in the wind to new locations of a forest
C) territorial songbirds in a mature forest during mating season

D) mushrooms growing on the floor of an old growth forest

D) mushrooms growing on the floor of an old growth forest

19
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Which statement best explains survivorship curve B?
A) It is likely a species that provides little postnatal care, but lots of care for offspring during midlife as indicated by increased survivorship.
B) This curve is likely for a species that produces lots of offspring, only a few of which are expected to survive.
C) It is likely a species where no individuals in the cohort die when they are at 60-70% relative age.
D) Survivorship can only decrease; therefore, this curve could not happen in nature.

D) Survivorship can only decrease; therefore, this curve could not happen in nature.

20
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Which of the following examples are plausible explanations for a population that would produce curve A in the figure?

I. II. III.

Ongoing predation of rabbits throughout their lives Susceptibility of older humans to heart disease High seedling mortality in sunflowers

A) I only
B) II only
C) I and II
D) II and III

B) II only

21

Imagine that you are managing a large game ranch. You know from historical accounts that a species of deer used to live there, but they have been extirpated. After doing some research to determine what might be an appropriately sized founding population, you reintroduce them. You then watch the population increase for several generations, and graph the number of individuals (vertical axis) against the number of generations (horizontal axis). With no natural predators impacting the population, the graph will likely appear as ________.

A) a diagonal line, getting higher with each generation B) an "S" that ends with a vertical line
C) an upside-down "U"
D) a "J," increasing with each generation

D) a "J," increasing with each generation

22
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In the figure, which of the arrows represents the carrying capacity? A) arrow A
B) arrow B
C) arrow C

D) Carrying capacity cannot be found in the figure because species under density-dependent control never reach carrying capacity.

C) arrow C

23

32) Which statements about K are correct?

  1. I) K varies among populations.
  2. II) K varies in space.
  3. III) K varies in time.
  4. IV) K is constant for any given species.

A) only I and III
B) only II and IV
C) only I, II, and III
D) only II, III, and IV

C) only I, II, and III

24

As N approaches K for a certain population, which of the following outcomes is predicted by the logistic equation?
A) The population growth rate will not change.
B) The population growth rate will approach zero.

C) The population size will increase exponentially.
D) The carrying capacity of the environment will increase.

B) The population growth rate will approach zero.

25

Which of the following causes populations to shift most quickly from an exponential to a logistic population growth?
A) favorable climatic conditions
B) removal of predators

C) decreased death rate
D) competition for resources

D) competition for resources

26
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Which of the following graphs best illustrates the growth curve of a small population of rodents that has increased to a static carrying capacity?

D

27

18) Which of the following scenarios would provide the most accurate 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-meter-square plots and extrapolate this number to the fraction of the study area these plots represent.

C) Use the mark-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.

B) Count the number of pine trees in several randomly selected 10-meter-square plots and extrapolate this number to the fraction of the study area these plots represent.