Deck 19: Growth of Populations

Question 1

The term "population density" describes the

A) body size of different species.
B) number of individuals per unit area.
C) number of populations per unit area.
D) number of species per unit area.

Answer 1

B

Question 2

The definition of an area,relative to a population study,

A) is constant.
B) is always 1 square meter.
C) depends on the questions being asked.
D) depends on whether the area is terrestrial or aquatic.

Answer 2

C

Question 3

A population of 100 individuals has a doubling time of 25 years.What size will this population be in 100 years?

A) 100
B) 400
C) 800
D) 1,600

Answer 3

D

Question 4

Which of the following populations would be MOST likely to experience a J-shaped growth pattern?

A) all of the animals in the San Diego Zoo
B) single-celled Paramecia without a constant food supply
C) a founding colony of rats on a small island with abundant resources
D) a beehive infected midsummer with a deadly bacterial disease

Question 5

Nene,Hawaiian geese,live on Maui.Their population density is approximately 0.2 per square kilometer and Maui is approximately 1,800 square kilometers in size.Approximately how many nene live on Maui?

A) 18
B) 130
C) 360
D) 1,800

Question 6

A population is counted at 100 individuals in 1998.In 2006,a new count found 1,600 individuals.The doubling time for the population is ________ year(s).

A) 0.5
B) 1
C) 1.5
D) 2

Question 7

Which of the following has the highest population density?

A) 1 grasshopper living in an area of 10 square meters
B) 100 rabbits living in an area of 10,000 square meters
C) 200 sparrows living in an area of 20,000 square meters
D) 1,500 oysters living in an area of 1,500 square meters

Question 8

Which of the following pieces of information would be MOST useful in determining whether a population is undergoing logistic growth versus exponential growth?

A) total population size taken during a current census
B) population doubling time
C) the carrying capacity for the same species in a different environment
D) the shape of the growth curve for the population over time

Question 9

A giant puffball mushroom can produce and release trillions of spores.With this many spores produced,why do giant puffball mushrooms undergo logistic growth in established habitats?

A) Puffball mushrooms use chemicals to limit the number of spores that survive to ensure that adults have access to nutrients.
B) The length of time for spore germination to occur is one factor that leads to logistic growth in all species.
C) Limiting resources, such as food, water, and space, control the maximum population size of all species.
D) Mushrooms are biologically unique organisms that are incapable of experiencing exponential growth even in habitats with unlimited resources.

Question 10

There were 5.2 people per acre in 2012.A census in 2017 found there were 1.2 people per acre.This change represents a(n)________ in population ________.

A) decrease; size
B) decrease; density
C) increase; size
D) increase; density

Question 11

The size of a population can be decreased by

A) a higher birth rate.
B) immigration.
C) emigration.
D) a reduced death rate.

Question 12

A population of 100 individuals is undergoing exponential growth with a population doubling time of 1 year.What size will this population be in 2 years?

A) 100
B) 150
C) 200
D) 400

Question 13

Which of the following is a true statement based on the map shown below?

A) The population density of Aedes aegypti mosquitoes is highest in the Southeast United States.
B) Northern states are not within the range of Aedes aegypti mosquitoes.
C) Southern states are affected by Zika virus.
D) The population size of Aedes aegypti mosquitoes is 1.5 million in the United States.

Question 14

Which of the following choices best explains why some introduced species experience an initial period of exponential growth when they first move from their native habitats into a new habitat?

A) They do not yet have any natural predators or diseases in their new habitat.
B) Most introduced species show better survival in new habitats than in their old ones.
C) Because most native species display exponential growth, many introduced species will do so also.
D) Native species always leave open habitat types that a new species can inhabit.

Question 15

A population will remain at a constant size when emigration equals immigration and

A) food is not a limiting factor.
B) births equal deaths.
C) predators leave the area.
D) available space remains the same.

Question 16

Which of the following statements does NOT explain why population density is often difficult to measure?

A) Individuals may be difficult to detect within some habitats.
B) The population size may be very large.
C) An accurate count of the population size may not be available.
D) Individuals may be moving between populations.

Question 17

In a neighborhood with an area of 500 acres,there are 3,000 mosquitoes.The population density in this neighborhood

A) is 6 mosquitoes per acre.
B) is 3,000 mosquitoes.
C) is 1.5 million mosquitoes per acre.
D) cannot be determined from the information given.

Question 18

A new species is introduced into a given area.The population size begins to grow slowly,then at a very rapid rate,and finally levels off at a stable number.This growth pattern is best represented by a(n)

A) oscillating cycle.
B) J-shaped population curve.
C) C-shaped population curve.
D) S-shaped population curve.

Question 19

There were 250 elk in a population within a park in 1900.By 2000 there were 325 elk.This change represents a(n)________ in population ________.

A) decrease; size
B) decrease; density
C) increase; size
D) increase; density

Question 20

According to the figure shown below,human populations began to experience exponential growth around

A) 160,000 BCE.
B) 1800.
C) 1945.
D) 2005.

Question 21

The carrying capacity for Paramecia caudatum as shown in the figure below is

A) 12 days.
B) 200/ml of medium.
C) 100/ml of medium.
D) 24 days.

Question 22

Which of the following would likely occur as a population reaches carrying capacity?

A) Density-independent deaths would increase.
B) Density-dependent deaths would increase.
C) Use of resources, such as food and space, would decrease.
D) Birth rates would increase to maintain population size.

Question 23

The effects of pollution are generally considered to be density-independent because

A) the contamination level of any organism is unaffected by variations in population density.
B) when food supplies become limited, the organisms are more likely to consume contaminated foods.
C) at high densities, the organisms are more likely to contact the pollutant.
D) when the organisms are stressed by overcrowding, the pollutant becomes more toxic.

Question 24

The graph below shows the growth of a population of Paramecium caudatum.The greatest amount of daily growth occurred when the population was at approximately ________ percent of its carrying capacity.

A) 10
B) 25
C) 50
D) 100

Question 25

The decrease in the availability of food or cover that accompanies increasing population size illustrates the concept of a(n)________ factor.

A) density-dependent
B) density-independent
C) exponential growth
D) logistic growth

Question 26

The maximum population size that can be supported by its habitat is known as

A) maximum increase.
B) carrying capacity.
C) exponential growth.
D) population balance.

Question 27

If a population is growing with no constraints on its resources,the population will

A) grow exponentially.
B) grow logistically.
C) remain at its carrying capacity.
D) double every 30 days.

Question 28

Density-dependent factors are more likely to limit population growth when

A) there are more individuals living in the same amount of space.
B) the population moves into a larger habitat.
C) food is abundant.
D) weather conditions become milder.

Question 29

When an isolated population reaches its carrying capacity,

A) the birth rate > the death rate.
B) the birth rate = the death rate.
C) the birth rate < the death rate.
D) It is not possible to generalize these values.

Question 30

The top of the "S" in an S-shaped curve indicates that the population

A) is on the verge of collapse.
B) is experiencing abnormally heavy pressure from predators.
C) has reached its carrying capacity.
D) is poised for further exponential growth.

Question 31

The carrying capacity of owls in an Alaskan forest is seven per square kilometer.What will happen if 12 owls are confined to a 1-square-kilometer area?

A) The owls will survive together and develop ways to share resources.
B) The owls might survive but the population size in the future will most likely be close to seven.
C) The population of owl prey organisms will increase proportionately to support a larger population of owls.
D) A short-term exponential growth of owls will occur because more mating pairs will form.

Question 32

Which of the following populations would be MOST vulnerable to an outbreak of disease?

A) 10 grasshoppers living in an area of 100 square meters
B) 100 rabbits living in an area of 10,000 square meters
C) 200 sparrows living in an area of 20,000 square meters
D) 250,000 people living in an area of 100,000 square meters

Question 33

For most populations,irregular fluctuations in size or density

A) are less commonly experienced than the smooth J-shaped growth curve.
B) occur commonly before carrying capacity is reached.
C) are more common than the smooth J-shaped growth curve.
D) occur only when density-independent factors dominate.

Question 34

Which of the following statements about carrying capacity is true?

A) An S-shaped curve represents a population's ability to increase its numbers above the carrying capacity of its habitat.
B) J-shaped curves show the immediate limiting effect of carrying capacity on a newly introduced organism.
C) The carrying capacity is the same for all organisms in the same area.
D) The carrying capacity is established by the resource with the most limited availability.

Question 35

In the figure below,the willow tree population leveled off at 475 trees and remained stable in the early 1980s.This most likely occurred because the

A) trees occupied all of the available space that willows were able to occupy.
B) tree seedlings were shaded by the grasses shown in the illustration.
C) population growth rate exceeded the death rate.
D) trees depleted all of the nutrients in the soil and the trees could no longer grow.

Question 36

Which of the following situations illustrates a link between the effects of density-dependent and density-independent factors?

A) A flood causes a river to overflow and drown a herd of deer.
B) A drought occurs; a small herd of deer survives, whereas a larger herd in the same area perishes.
C) A population of deer increases to a size at which individuals are competing with each other to get enough food.
D) Density-dependent and density-independent factors cannot affect the same population of organisms at the same time.

Question 37

The figure below shows that the human population was small and relatively stable for nearly 12,000 years but has increased dramatically in the past 200 years.How might this increase in population growth be explained?

A) Disease prevented any significant growth of the human population.
B) For most of human history people were too malnourished to have children.
C) People simply chose to have fewer children in the past than at present.
D) Prior human populations were at existing carrying capacities, but newly developed technologies have raised the carrying capacity and permitted the recent expansion.

Question 38

In 1978,a drought on the Galapagos Islands caused a reduction in the production of seeds upon which one of Darwin's finches,a kind of bird,fed.This caused a decrease from 1,400 to 200 birds.This population change factor

A) would not be considered a part of the carrying capacity for these birds.
B) was density-dependent.
C) was density-independent.
D) resulted in exponential growth for the bird population.

Question 39

According to the figure below,human populations are projected to reach carrying capacity in approximately ________ years.

A) 30
B) 75
C) 85
D) 105

Question 40

Is it reasonable to expect that all habitats suitable for a given organism will have the same carrying capacity for that organism?

A) Yes; unless the carrying capacities are the same, the habitat would not be suitable.
B) Yes; the carrying capacity is determined solely by the type of organism being considered.
C) No; an organism may be able to live in many locations, but the resources it requires may be available in varying amounts.
D) No; it is not possible for two habitats to have the same carrying capacity.

Question 41

In a neighborhood in Rio de Janeiro,the mosquito population ________ is 3.85 female mosquitoes per acre.

Question 42

Predation increases are responsible for density-________ changes in population size.

Question 43

Arctic foxes eat small mammals called lemmings.If lemmings are the main food source of arctic foxes in an area,what would be expected when lemming populations decrease?

A) A density-independent decrease would occur in arctic fox populations.
B) A density-dependent decrease would occur in arctic fox populations.
C) Arctic foxes would remain at their carrying capacity by switching to another food source.
D) The arctic fox population would decrease slightly before rising again.

Question 44

Population size ________ when the combination of death and emigration rates is lower than the combination of birth and immigration rates.

Question 45

At room temperature,a population of dangerous bacteria on a piece of raw chicken increases from 100,000 to 400,000 in 40 minutes.Its doubling time is ________ minutes.

Question 46

When bacteria become resistant to antibiotics and experience an unpredicted,sudden increase in population size,they are exhibiting a(n)

A) irregular fluctuation.
B) cyclical fluctuation.
C) S-shaped growth curve.
D) logistic growth pattern.

Question 47

Which of the following examples illustrates a cyclical fluctuation?

A) A new disease is introduced into a population of humans and 15 percent of the humans die.
B) A population of snowy owls decreases when weasel populations decrease.
C) A ban on the pesticide DDT precedes an increase in a bald eagle population.
D) A small population of lizards is introduced on an island and resources are unlimited.

Question 48

If we humans do not limit our population growth rate,we will exceed the ________ of our environment,leading to a larger population than the environment can support.

Question 49

Studies of the population-size cycles seen between the snowshoe hare and the Canadian lynx showed that lynx populations ________ in size when hare populations ________ in size.

A) decrease; increase
B) increase; decrease
C) decrease; decrease
D) There is no relationship between population sizes of snowshoe hare and Canadian lynx.

Question 50

A J-shaped population growth pattern indicates that a population is

A) utilizing all resources in an area and birth rates are equal to death rates.
B) growing at its maximum rate and birth rates are higher than death rates.
C) unaffected by diseases and birth rates are equal to death rates.
D) closely linked to prey, which are available in unlimited supply, and the birth rates are higher than death rates.

Question 51

The success of ending the spread of Zika virus through the use of genetically modified (GM)mosquitoes is NOT dependent on

A) mosquito populations.
B) the amount of virus circulating between humans and mosquitoes.
C) human populations.
D) development of a Zika vaccine.

Question 52

Which of the following statements describes a cyclical fluctuation?

A) a predictable pattern in which a mosquito population increases and decreases in size based on precipitation
B) an unpredictable change in which a mosquito population develops resistance to an insecticide
C) A rare natural disturbance limits the growth of mosquitoes and causes a decrease in the typically stable population size.
D) Limited water in an area restricts the growth of a mosquito population to a level considered to be carrying capacity.

Question 53

Lynx feed on rabbits,and the growth curves for these two species fluctuate together.This relationship is an example of a(n)

A) S-shaped growth curve.
B) J-shaped growth curve.
C) irregular fluctuation.
D) tightly linked cycle.

Question 54

A predictable pattern in which the population sizes of two species increase and decrease in response to each other's densities is called a(n)

A) irregular fluctuation.
B) cyclical fluctuation.
C) density-dependent population change.
D) density-independent population change.

Question 55

One measure of population growth is the period in which a population increases to twice its size.This is referred to as the ________ of the population.

Question 56

Weather is a density-________ factor that can affect the size of a population.

Question 57

Genetic modification of mosquitoes is designed to reduce the population ________ of mosquitoes.

Question 58

When comparing the peaks on both of the graphs below the lynx population reaches its maximum

A) slightly after the hare population reaches its maximum.
B) slightly before the hare population reaches its maximum.
C) at the same time that the hare population reaches its maximum.
D) at random intervals that do not appear linked to hare populations.

Question 59

A population change in which the populations of two species rise and fall together in a predictable pattern is called a(n)________.

Question 60

If there are 100 people living in a 2-square-kilometer area,the population density is ________ people per square kilometer.

Question 61

MATCHING
Match each term to a statement listed below.
a.population size
b.population density
c.carrying capacity
d.logistic growth
e.exponential growth
unlimited growth of a population with no constraint on resources

Question 62

Your friend is planning a trip to Africa.She mentions to you that that she is more worried about contracting sleeping sickness than she is worried about contracting mosquito-transmitted malaria after watching a TV show highlighting sleeping sickness.Based on the image below indicating the rank of the 15 deadliest animals,is her fear fact-based?

Question 63

MATCHING
Match each term to a statement listed below.
a.population size
b.population density
c.carrying capacity
d.logistic growth
e.exponential growth
total number of individuals in a population within a given area

Question 64

What causes an S-shaped growth curve to flatten out at the top?

Question 65

Why do logistic growth curves have an "S" shape?

Question 66

Determine which examples are density-dependent population changes and which are density-independent population changes.
a.density-dependent population change
b.density-independent population change
A virus spreads through a population of wild dogs and 20 percent of the dogs die.

Question 67

How could a researcher use historical population size data for a predator and its prey to determine whether the two strongly influence each other?

Question 68

Determine which examples are density-dependent population changes and which are density-independent population changes.
a.density-dependent population change
b.density-independent population change
An insecticide used to reduce mosquito populations indirectly decreases bald eagle populations.

Question 69

MATCHING
Match each term to a statement listed below.
a.population size
b.population density
c.carrying capacity
d.logistic growth
e.exponential growth
number of individuals within a population per unit of area

Question 70

Is a death rate increase from influenza an example of a density-dependent population change or a density-independent population change?

Question 71

Describe the shape of the growth pattern for a population undergoing exponential growth.When would a population experience this type of growth?

Question 72

A population of 10 yeast cells is put into a flask with growth media that contains all the nutrients required for growth.The yeast has a doubling time of 2 hours; 4 hours after adding the yeast to the flask the population size is 40 cells.After 3 days the population size stabilizes at around 500 cells.Is this population exhibiting logistic or exponential growth? Explain your reasoning.

Question 73

Is it possible for the carrying capacity of a population to change? If so,give an example.If not,explain why.

Question 74

In nature,populations tend to experience unpredicted rises and falls in population size.This type of change is called a(n)________.

Question 75

You are told that the population size of mosquitoes is 50.What information would you need to allow you to determine the population density?

Question 76

Two humans are infected with a new,deadly form of influenza.One of the individuals lives in a crowded city and travels frequently for her job.The other individual lives in a remote,rural village with limited travel into or out of the village.Which of these situations is more likely to impact human populations? Is this situation considered density-dependent or density-independent?

Question 77

MATCHING
Match each term to a statement listed below.
a.population size
b.population density
c.carrying capacity
d.logistic growth
e.exponential growth
the maximum sustainable population size in a given environment

Question 78

How would population doubling time change as a population experiencing exponential growth approaches carrying capacity?

Question 79

Use a specific example to explain how population density may change for people living in one country without any change in population size.

Question 80

Determine which examples are density-dependent population changes and which are density-independent population changes.
a.density-dependent population change
b.density-independent population change
A wildfire sweeps through a forest and kills 90 percent of the oak trees.