Deck 11: Population Growth and Regulation

Question 1

Refer to the figure.
Which event lead to a substantial decrease in the human population?

A) Accidents from metal working
B) Invention of tools to help with plowing and irrigation
C) Deaths from bubonic plague
D) The beginning of the agricultural revolution

Answer 1

C

Question 2

When did the world population first reach 1 billion?

A) 1544
B) 1825
C) 1930
D) 2019

Answer 2

B

Question 3

The top five countries currently add approximately 40 million people a year to the world's population. Which of the following countries is not one of these top five?

A) China
B) United States
C) Nigeria
D) Italy

Answer 3

D

Question 4

A population of turtles contained 342 individuals at the end of the year 2013. Since then, 44 have died, 37 were born, 17 immigrated, and 6 emigrated. What is the population size now?

A) 298
B) 335
C) 346
D) 385

Question 5

A fictional animal, the tribble, reproduces in synchrony at regular intervals. When the logarithm of a particular tribble population was plotted against time, the result was a straight and increasing line. Which statement about the tribble population is false?

A) The tribble population is increasing in size geometrically.
B) The $\lambda$ of the tribble population is constant and greater than 1.
C) If the actual population size were plotted against time, the result would be an increasing J-shaped curve.
D) r = 0.

Question 6

A population of Drosophila mauritiana reproduces in synchrony at discrete time periods every generation, and generations occur at two-week intervals. The current population size is 1,000, and its geometric population growth rate is 3.0 per generation. What will the expected size of the population be after six weeks?

A) 3,000
B) 9,000
C) 27,000
D) 81,000

Question 7

In comparing exponential and geometric growth, which statement is true?

A) Lambda (?) can be calculated from r and is equivalent to the natural logarithm of r.
B) Lambda (?) can be calculated from r and is equivalent to "e" raised to the r power.
C) The multiplier r can be calculated from $\lambda$ , and is equivalent to "e" raised to the $\lambda$ power.
D) The multiplier r is not used in estimating exponential or geometric growth.

Question 8

Which population would be expected to remain stable in size?

A) A population with an r of < 1
B) A population with a $\lambda$ of 1 or an r of 0
C) A population with an r of > 0
D) A population with a $\lambda$ of 0 and an r of 1

Question 9

If there are 100 plants in a population in year 1, and 120 plants in the population in year 2, what is $\lambda$ ?

A) 0.12
B) 1.2
C) 12
D) 120

Question 10

A continuously growing population of alligators has a population size of 1,000 and an intrinsic rate of increase of r = 0.05 per year. Assuming that this rate of increase remains the same, about how long should it take for the population to grow larger than 4,000 individuals? (Note: The natural logarithm of 2 is about 0.70.)

A) Less than 4 years
B) A little more than 7 years
C) About 14 years
D) A little more than 27 years

Question 11

Which statement about population growth is true?

A) Exponential population growth is always faster than geometric population growth.
B) We use the term "exponential growth" when the individuals in the population reproduce in synchrony at discrete intervals.
C) A population that has a $\lambda$ of 0.88 should grow in size.
D) There are limits to the growth of populations.

Question 12

Which statement about population growth is true?

A) Population growth can be exponential for only as long as environmental conditions are favorable.
B) Population growth of field samples always has a $\lambda$ of approximately 1.
C) Population growth models do not apply to humans.
D) Population growth can continue indefinitely.

Question 13

Which statement about density-independent factors is true?

A) Davidson and Andrewartha's studies of thrips (Thrips imaginis) showed that density-independent factors play a major role in the annual fluctuations of abundance of this species.
B) Density-independent factors increase the size of populations when population size is low.
C) Density-independent factors decrease the size of populations when population size is high.
D) Food and habitat availability are density-independent factors that influence population size.

Question 14

Refer to the figure.
Based on the figure, which statement about Davidson and Andrewartha's experiment on thrips (Thrips imaginis) is true?

A) Davidson and Andrewartha's model of thrips per rose was exactly the same as the observed numbers.
B) The predicted numbers closely resembled the observed numbers.
C) The observed numbers of thrips was always lower that the predicted model but showed the same general trends.
D) The predicted numbers model accurately reflected the observed numbers some years but in other years the predicted model was very different than the observed numbers of thrips.

Question 15

Which of the following would not be an example of density-dependent factors regulating population size?

A) The number of possible territories for robins is limited; thus when population sizes are high, a lower proportion of individuals can produce offspring.
B) In conditions of overcrowding, some desert pupfish living in ponds will emigrate to other ponds if given the opportunity.
C) Predation on mosquitofish is high, regardless of population size.
D) In conditions of high density, mice are more susceptible to mortality from heat stress.

Question 16

Population regulation occurs when

A) the population has reached a stable age distribution.
B) density-dependent factors affect birth, death, and emigration rates.
C) density-independent factors affect birth, death, and emigration rates.
D) the population is close to zero.

Question 17

What was the difference between the treatment and the control groups in Arcese and Smith's studies of the effects of density on song sparrows?

A) Additional young birds were added to the treatment group.
B) Predators were removed from the treatment group.
C) The control group was provided with extra food.
D) The treatment group was provided with extra food.

Question 18

Refer to the figure.
The birth and death rates of a population of garter snakes were monitored over 11 years, during which time population density varied considerably. According to the figure, which statement about the populations is true?

A) Density-independent factors are regulating population size.
B) At high population sizes, the death rate is higher than it is at low population sizes.
C) Birth rate declines at high population sizes.
D) Birth rates equal death rates.

Question 19

Which statement about logistic growth is false?

A) The carrying capacity is the maximum population size that can be supported by the environment for one year.
B) At low densities, logistic growth is similar to exponential growth.
C) At the carrying capacity, there is no population growth in the logistic model.
D) Logistic growth of a population can be represented by an S-shaped curve.

Question 20

The logistic equation assumes that

A) the per capita growth rate is a constant.
B) the per capita growth rate declines with increasing density.
C) populations will increase in size indefinitely.
D) r increases in a straight line as density increases.

Question 21

A population of prickly pear cacti has 1,500 individuals with an intrinsic rate of increase (r) of 0.3. As the population gets close to its carrying capacity of 2,000 individuals, how will r change?

A) r will be near 0.
B) r will be less than zero.
C) r will be slightly less than 0.3.
D) r will be slightly more than 0.3.

Question 22

Suppose populations of a beetle species follow the logistic equation for growth. If a population is at 3/4 of its carrying capacity and its (per capita) growth rate in the absence of density-dependent regulation is r, what is its growth rate now?

A) 0
B) r/4
C) r/2
D) 3r/4

Question 23

Refer to the figure.
Based on the figure, how long did it take willows to reach their carrying capacity in Australia?

A) It never reached carrying capacity.
B) 12 months
C) 1.2 years
D) 12 years

Question 24

Refer to the figure.
Based on the data in the figure, what is the carrying capacity in this environment?

A) 5
B) 10
C) 28
D) 39

Question 25

Which statement about Pearl and Reed's application of the logistic growth curve to U.S. population growth is true?

A) Their logistic curve provided a good fit to the U.S. population growth up until about 1950.
B) They predicted a carrying capacity of over 300 million.
C) The U.S. population exceeded the carrying capacity that they estimated by 1950.
D) The logistic curve would only work if the U.S. imported significant amounts of food.

Question 26

Life tables can do all of the following except

A) provide a summary of how survival and reproductive rates vary by age or size.
B) help predict future population trends.
C) be used as a tool for population management.
D) ensure survival from one life stage to the next life stage.

Question 27

The country of Guatemala is currently experiencing rapid population growth, Greece is experiencing essentially zero population growth, and Germany is experiencing negative population growth. Assuming that age-specific fecundities are similar in these three countries, which of the following is most likely?

A) Germany should have the highest proportion of young individuals.
B) Greece should have the highest proportion of young individuals.
C) Guatemala should have the highest proportion of young individuals.
D) Guatemala should have the lowest proportion of young individuals.

Question 28

Suppose you are constructing a life table for a population of a small perennial plant. Currently, there are 650 plants that are in age class 0, 347 in age class 1, 123 in age class 2, and 55 in age class 3. Based on previous work, the expected survival rates of plants are S₀ = 0.4, S₁ = 0.6, and S₂ = 0.8.

- Assuming that the expected survival rates remain the same, about how many plants will be in age class 2 in 12 months?

A) 73
B) 98
C) 139
D) 208

Question 29

Suppose you are constructing a life table for a population of a small perennial plant. Currently, there are 650 plants that are in age class 0, 347 in age class 1, 123 in age class 2, and 55 in age class 3. Based on previous work, the expected survival rates of plants are S₀ = 0.4, S₁ = 0.6, and S₂ = 0.8.

-Assuming that the expected survival rates remain the same, about how many plants that are expected to be in age class 2 in 24 months?

A) 83
B) 156
C) 208
D) 260

Question 30

Which organism has a survivorship curve most like that of humans living in the United States?

A) Dall mountain sheep
B) Song thrushes
C) The desert shrub, Cleome droserifolia
D) Mud turtles

Question 31

Which type of survivorship curve is seen most frequently in the wild?

A) Type I (most individuals survive to old age)
B) Type II (constant rate of mortality throughout lifetime)
C) Type III (most individuals die young)
D) Type I and Type II are about equally common.

Question 32

Refer to the figure.
Based on the figure, an acorn barnacle has _______ chance of surviving to age 5 when compared to a song thrush.

A) a significantly higher
B) an approximately equal
C) no
D) much lower

Question 33

Which statement about life tables is false?

A) Life tables can be based on life-cycle stage as well as age.
B) Survivorship (l_x) can increase from one age class to the next.
C) The age-specific survival rate is the chance that an individual of one age will survive to the next age class.
D) Fecundity is the average number of offspring produced by females of a particular age class.

Question 34

Suppose that researchers are studying the life history of a population of gorillas, a species in which individuals can live for several decades. They can assess the ages of the gorillas with high accuracy, but because of funding constraints, they are limited to three years of study. Which table will the researchers be able to construct?

A) A full cohort life table
B) A static life table
C) A survivorship life table
D) A dynamic life table

Question 35

Refer to the table.
.

-
The table shows the survivorship, fecundity, and life expectancies for U.S. females of various ages as of 2009. In 2009, how many more years was a 50-year-old woman expected to live?

A) 0.958
B) 30.1
C) 33.2
D) 66.7

Question 36

Refer to the table.


- The table shows the survivorship, fecundity, and life expectancies for U.S. females of various ages as of 2009. At which age was fecundity the highest in 2009?

A) Age 20
B) Age 25
C) Age 30
D) Age 35

Question 37

Refer to the table.


-The table shows the survivorship, fecundity, and life expectancies for U.S. females of various ages as of 2009. At approximately which age were half the females still alive in 2009?

A) 68
B) 73
C) 78
D) 84

Question 38

Refer to the table.


-The table shows the survivorship, fecundity, and life expectancies for U.S. females of various ages as of 2009. Approximately 1.5 million females were born in the United States in 2009. Based on this fact and the life table data, how many of them should we expect to live to at least age 100?

A) 3,300
B) 22,000
C) 40,500
D) 178,500

Question 39

Refer to the figure.
Based on the figure, what is the approximate difference in the probability that a Gambian will survive to age 40 if she was born in the "hungry season" (July-October) compared with another time of the year?

A) 0%
B) About 5%
C) About 12%
D) About 50%

Question 40

Refer to the figure.
Based on the figure, what year is the world population growth rates expected to be only 1%?

A) 1960
B) 2000
C) 2020
D) never

Question 41

Refer the figure.
According to the figure, which loggerhead sea turtle group, when 50% protected by management practices, was estimated to produce a positive increase in survival growth rate?

A) Egg/hatchling
B) Small juvenile
C) Large juvenile
D) Subadult

Question 42

Over the past 2,000 years, the overall human population has grown

A) exponentially.
B) more than exponentially.
C) according to the logistic growth equation.
D) linearly.

Question 43

Which statement is not consistent with projected trends in human population growth?

A) According to the U.N., the low projection for human population size by the year 2050 is between 7 and 8 billion.
B) According to the U.N., the high projection for human population size by the year 2050 is over 10 billion.
C) The carrying capacity of humans depends greatly upon how we use resources.
D) Human doubling time has decreased since the early 1960s leading to the human population doubling every decade.

Question 44

The total area of productive ecosystems required to support a particular individual or population is known as its

A) carrying capacity.
B) ecological footprint.
C) logistic growth curve.
D) survivorship curve.

Question 45

Suppose you are studying consumption patterns to determine how much land area would be required to support a certain population size, in terms of the number of tons of wheat produced by an area compared to the number of tons of wheat consumed by the people in that area. Based solely on wheat production and consumption, which area has the smallest ecological footprint?

A) Area 1: 600 tons of wheat produced; 200 tons consumed
B) Area 2: 150 tons of wheat produced; 100 tons consumed
C) Area 3: 600 tons of wheat produced; 500 tons consumed
D) Area 4: 700 tons of wheat produced; 300 tons consumed

Question 46

You are studying a population of mice. The starting population size is 200 adults. Following reproduction, 10% of adults die. The birth rate is 15% and the emigration rate is 30%, but only very young individuals disperse. The population receives 44 immigrants, existing adults reproduce and then some die, and of the offspring that are produced some emigrate. What is the total population size following reproduction, death of adults, birth of young, emigration of young, and immigration of outsiders?

Question 47

Species A is a nonreproductive age shrub you have been studying for 3 years after a wildfire destroyed all the vegetation on your field site. Based on studies of Species A at a control, no wildfire field site, it has an expected survival rates of S₁ = 0.75, S₂ = 0.65 S₃ = 0.55. During year 0 in your wildfire field site, there were 340 individuals tagged. Assuming the same survival rate at the wildfire site as the control site how many plants would you expect in:
(a) Year 1?
(b) Year 2?

Question 48

Species A is a nonreproductive age shrub you have been studying for 3 years after a wildfire destroyed all the vegetation on your field site. In year 0, 340 individuals were tagged. In year 1, 288 individuals were still alive. In year 2, 250 individuals were alive. In year 3, 200 individuals remained. Based on this data, calculate:
(a) The survivorship (l_x) for year 1
(b) The survivorship (l_x) for year 3.

Question 49

You are asked to construct a life table for Species A, a nonreproductive shrub you have been studying for 3 years after a wildfire destroyed all the vegetation on your field site. What type of life table would you construct for this scenario? Why?

Question 50

Species A is a nonreproductive age shrub you have been studying for 3 years after a wildfire destroyed all the vegetation on your field site. Data from the control, no wildfire site, documents that species A becomes reproductive in year 3. At the control site, there are 432 species A shrubs in year 3 and 523 in Year 4. What is species A's $\lambda$ ?

Question 51

Species A is a nonreproductive shrub you have been studying for 3 years after a wildfire destroyed all the vegetation on your field site. In year 0, 340 individuals were tagged. In year 1, 288 were still alive. In year 2, 250 were alive. In year 3, 200 remained. The data from the control, no wildfire site, documents that species A becomes reproductive in year 3 with a $\lambda$ of 1.21. How many shrubs would you predict will be at the wildfire site in year 4?

Question 52

Species A is a nonreproductive shrub you have been studying for 3 years after a wildfire destroyed all the vegetation on your field site. In year 0, 340 individuals were tagged. In year 1, 288 were still alive. In year 2, 250 were alive. In year 3, 200 remained. The data from the control, no wildfire site, documents that species A becomes reproductive in year 3 with a $\lambda$ of 1.21. Identify the density-independent factor(s) and some of the density-dependent factor(s) in this scenario and role they play in determining species A's population density.

Question 53

Species A is a nonreproductive shrub you have been studying for 3 years after a wildfire destroyed all the vegetation on your field site. In year 0, 340 individuals were tagged. In year 1, 288 were still alive. In year 2, 250 were alive. In year 3, 200 remained. Suppose that the carrying capacity of this environment for species A is 500 individuals. How would you expect the growth rate to change over the next 5 years? If the carrying capacity for species A was 2,000, how would you expect the growth rate to change over the next 5 years?

Question 54

Briefly explain why calculating human population growth and carrying capacity is often more difficult than determining population growth and carrying capacities in other species.

Question 55

A frog pond contained 27 adults at the beginning of spring. During the summer, 4 immigrated from a neighboring pond, 12 emigrated during the summer drought, 3 were eaten by brim, and 42 tadpoles hatched. What is the current population size of frogs in the pond?

A) 27
B) 42
C) 58
D) 74

Question 56

A population of rabbits reproduces in synchrony at discrete time periods each year. If the current population is 150 and its geometric population growth rate is 1.4 per year, the expected size of the population after two years will be

A) 140.
B) 196.
C) 210.
D) 294.

Question 57

A continuously growing population of bears has a population size of 500 and its intrinsic rate of increase is r = 0.07 per year. Assuming that this rate of increase remains the same, about how long should it take for the population to reach 1,000? (Note: The natural logarithm of 2 is about 0.70.)

A) 5 years
B) 10 years
C) 14 years
D) 20 years

Question 58

Which population is likely to be increasing in size?

A) A population with an r of -0.04
B) A population with a $\lambda$ of 1.3
C) A population with a $\lambda$ of 0.98
D) A population with a $\lambda$ of 0

Question 59

Davidson and Andrewartha's studies of thrips (Thrips imaginis) showed that

A) annual fluctuations in population size could be predicted based on rainfall and temperature data.
B) annual fluctuations in population size were due primarily to density-dependent factors.
C) density-independent factors increase the size of populations when population size is low.
D) a fluctuation in weather altered birth rates but did not alter death rates.

Question 60

Which statement about density-dependent or density-independent growth is true?

A) A decrease in birth rate with increasing population size is a density-independent factor.
B) An increase in emigration rate with increasing population size is a density-dependent factor.
C) Only density-independent factors can regulate population size.
D) Density-independent factors do not have large effects on population size.

Question 61

Which statement about Arcese and Smith's studies of the effects of population density on song sparrows is false?

A) The number of young per female that survived to become independent of their parents increased with increasing density.
B) At high density, the population size of the sparrows was likely regulated by food shortages.
C) The number of eggs laid per female declined with increasing density.
D) Nesting pairs that were fed were found to produce many more young than did pairs in the control group.

Question 62

The maximum population size that can be supported indefinitely by the environment is

A) carrying capacity.
B) ecological footprint.
C) logistic growth curve.
D) survivorship curve.

Question 63

Refer to the figure.
Use the figure to determine the point at which the population growth rate is maximized under the logistic model.

A) The rate is maximized when N = K/2.
B) The rate is maximized when the population is extremely small.
C) The rate is maximized when K is reached.
D) The rate is maximized when K is surpassed.

Question 64

According to calculations done by Pearl and Reed in 1920, the carrying capacity of the United States is just under _______ million.

A) 100
B) 150
C) 200
D) 300

Question 65

Life tables can be based on all of the following except

A) ages of organisms.
B) life cycle stages of organisms.
C) sizes of organisms.
D) biogeographical locations of organisms.

Question 66

The rural community of Happyville has a population distribution made up of 112 individuals between the ages of 1-16, 222 individuals between 17-44, and 514 individuals over 45 years old. Based on this population distribution, without immigration or emigration, the population of Happyville would be expected to

A) stay the same for the next 50 years.
B) decline over the next 50 years.
C) increase for 5 years then remain the same.
D) increase over the next 50 years.

Question 67

Mountain gorillas put a lot of effort in raising their young, ensuring they are protected and well cared for. In a natural population in the absence of poaching, and a lack of habitat destruction and other manmade dangers, the mountain gorilla would represent which type of survivorship curve?

A) Type I
B) Type II
C) Type III
D) Type IV

Question 68

Refer to the table.
The table shows the survivorship, fecundity, and life expectancies for U.S. females of various ages as of 2009. If approximately 1.5 million females were born in the United States in 2009, how many of them should we expect to live to at least age 90?

A) 148,500
B) 305,000
C) 438,000
D) 654,000

Question 69

Which statement about ecological footprints is false?

A) The ecological footprint of the average American is much larger than that of the average person in much of the rest of the world.
B) Ecological footprints of populations do not change over time.
C) Ecological footprints can be used to estimate carrying capacities.
D) Calculations of ecological footprints are based on several sources of information, including agricultural productivity, resource use, and pollution.