Deck 21: Growth of Populations

Question 1

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 and specific characteristics of the species forming the population.
D) depends on whether the area is terrestrial or aquatic.

Answer 1

C

Question 2

The decrease in the availability of food,access to water,or access to cover that accompanies increasing population size illustrates the concept of a(n)

A) density-dependent factor.
B) density-independent factor.
C) emigration-related factor.
D) high-carrying capacity factor.

Answer 2

A

Question 3

Which of the following is likely to make the smallest contribution to annual changes in the size of a population?

A) extreme weather events such as a hurricane
B) an introduced species that preys on the population
C) global climate change
D) an outbreak of a highly infectious disease

Answer 3

C

Question 4

The change in size of a given population of organisms may have a direct impact on humans.The 1993 outbreak of hantavirus in the southwestern United States was partly due to a(n)

A) tightly linked cycle of human and hantavirus populations.
B) increase in the deer mouse population size.
C) decline in the desert salamander population, the normal hantavirus host.
D) increase in human population size.

Question 5

A population is counted at 100 individuals in 1998.In 2006,a new count found 1,600 individuals.What is the doubling time for the population?

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

Question 6

Nene,the Hawaiian goose,live in the wild on Hawaii,Maui,Kauai,and Molokai.The population density on Maui is 0.227 birds per square kilometer,and the island is 1,830 square kilometers in size.Approximately how many nene live on Maui?

A) 16
B) 150
C) 415
D) 12,400

Question 7

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

Question 8

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 9

Which of the following populations would be most vulnerable to an outbreak of a communicable 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 10

Which density-dependent process contributed most significantly to the recovery of the North American monarch butterfly population after the severe winter losses of 2002?

A) Unusually mild weather in the eastern United States greatly improved juvenile butterfly survival.
B) Butterfly predators starved when the monarch population dropped, and by the time it had recovered, Monarch population numbers were back up.
C) Egg production is inversely proportional to density; the surviving monarchs had ample resources and experienced maximal reproduction.
D) With fewer returning adults, there was less competition for food among the young caterpillars, and their survival rate was unusually high.

Question 11

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.

Question 12

Which of the following choices best explains why some introduced species experience an initial period of exponential growth?

A) They typically have fewer natural predators and/or parasites in their new habitat, so their growth is unhindered until a critical resource becomes limiting.
B) Most introduced species show improved survival in new habitats in comparison to their old ones.
C) Growth patterns are functions of the habitat; introduced species grow exponentially, and their growth is virtually identical to that of the native species.
D) Native species specialize, leaving open habitats that new species can use.

Question 13

The size of a population can be decreased by

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

Question 14

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 15

A population of 100 individuals is undergoing exponential growth,with a constant growth rate of 0.2 per year.What size will this population be in 2 years?

A) 100
B) 120
C) 144
D) 200

Question 16

Which of the following populations would be most likely to experience an S-shaped growth pattern?

A) the lion population living at the San Diego Zoo
B) paramecia in an experimental culture where food was added only at the beginning of the experiment
C) a wolf population after its reintroduction to a national park such as Yellowstone or Glacier, where they once lived but had become locally extinct
D) a beehive infected midsummer with a deadly bacterial disease

Question 17

The population explosion that occurred shortly after the Opuntia cactus was introduced to Australia is an example of

A) exponential growth.
B) emigration.
C) reduced population density.
D) a native species outcompeting an introduced species.

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) A-shaped population curve.
D) S-shaped population curve.

Question 19

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 20

A flock of geese (Flock A)has 100 individuals and an annual growth rate,r,of 1.5.Another flock (Flock B)has 200 individuals and an r of .7.Flock C has a population of 75 and an r of 2.Flock D has a population of 50 and an r of 4.Assuming no other factors are involved,which herd will be largest next year?

A) Flock A
B) Flock B
C) Flock C
D) Flock D

Question 21

In computing an individual's ecological footprint,which of the following would NOT be included?

A) energy demand
B) food use
C) goods and services use
D) education level

Question 22

Bald eagle populations reached such low numbers in the 1960s that some biologists predicted their extinction in the continental United States; what action appears to have been most significant in reversing their decline?

A) Eagle sanctuaries were established to provide protection for nesting eagles.
B) Bounties on eagle predators were enacted.
C) The use of DDT was banned in the United States.
D) Eagles were reared in captivity until reaching an age of self-sufficiency and then returned to the wild.

Question 23

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 24

Factors such as the age of reproductive maturity,maximum litter size,and the gestation period combine to produce an upper limit for the growth rate of any population; under what circumstances is that rate most likely to be seen?

A) when the population approaches a density that's 50 percent of its carrying capacity
B) when there are very few individuals in the population, for example, the initial colonists in a new habitat or the first few individuals of an introduced species
C) when the population reaches its carrying capacity
D) when the survivors following a population crash begin to reproduce

Question 25

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 factor with the most limited availability.

Question 26

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 27

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 is able to survive, 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) None of the above are correct because density-dependent and density-independent factors cannot affect the same population of organisms at the same time.

Question 28

Biologists estimate that the human population on Easter Island declined by 90 percent during the 200-year period between AD 1400 and 1600; what accounts for the crash of this population?

A) the introduction of novel diseases brought by visiting Polynesians
B) expanding forests and the consequent loss of farmland
C) the aftermath of a volcanic eruption
D) deforestation, soil erosion, and resource depletion

Question 29

In 1978,a drought on the Galápagos Islands caused a reduction in the production of seeds that one of the finches,a type of bird,fed upon.This resulted in a decrease from 1,400 to 200 birds.Drought,in this specific situation,

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

Question 30

The carrying capacity of owls in an Alaskan forest is 8 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 as malnourished adults, but the next generation will have no more than eight individuals.
C) The population of owl prey organisms will increase proportionately.
D) A short-term exponential growth of owls will occur.

Question 31

The amount of productive land and water that individuals or populations require to provide their required resources and dispose of its wastes is called the

A) sustainable area.
B) ecological footprint.
C) biological acreage.
D) environmental measure.

Question 32

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; the habitat is the location where all essential resources occur, but these resources may be available in varying amounts.
D) No; it is not possible for two habitats to have the same carrying capacity.

Question 33

The Rapanui people initiated the environmental disasters on Easter Island by first

A) planting crops that required too much water.
B) overfishing the lagoons around the island.
C) removing protective vegetation and exposing the soil to increased erosion.
D) using resources to make statues instead of using these resources as fertilizer.

Question 34

Examine the following graph,which shows the relationship between planting density and seeds produced per individual plant for Plantago major,also known as plantain weed. What statement best describes the relationship?

A) At high planting densities, both seed production per plant and total seeds produced decline.
B) At high planting densities, seed production per plant declines while total seeds produced remain constant.
C) At low planting densities, both seed production per plant and total seeds produced increase.
D) At high planting densities, seed production per plant declines while total seeds produced increases.

Question 35

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

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

Question 36

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

A) the level at which any organism is contaminated with pollutants 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 37

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 mortality pressure from predators or disease.
C) has reached its carrying capacity.
D) is poised for further exponential growth.

Question 38

The following graph shows the growth of a Paramecium population. 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 39

As a component of its solution for overpopulation,China has imposed a policy that legally limits families to one child; China's government is attempting to manipulate which population factor?

A) N
B) r
C) carrying capacity
D) food supply

Question 40

The following figure 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) Effective methods of intercontinental travel permitted humans to immigrate to locations better suited to support larger populations.
B) For most of human history, people were too malnourished to have many children.
C) People simply chose to have fewer children and smaller families 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 41

The type of growth that occurs when the population size increases by a constant proportion over time is known as ________.

Question 42

A group of interacting individuals of the same species living within the same area comprises a(n)________.

Question 43

When population size is high,the rate of deaths related to disease,starvation,predator,and accidents increases; because their rates vary with population size,these mortality factors are considered ________.

Question 44

Populations generally change in size over time.

Question 45

Using the environment in ways that can continue indefinitely,neither depleting essential resources nor causing environmental damage,is defined as ________ use.

Question 46

One of the greatest concerns to ecologists today is the possibility that the current rate of human population growth will soon produce a human population that exceeds the ________ of our environment.

Question 47

The rates of population growth and emigration are directly proportional.

Question 48

Food shortages and communicable disease are examples of factors that can increase a population's death rate while simultaneously ________ its growth rate.

Question 49

If everyone lived a lifestyle as consumptive as American college students,the total acreage required would be the equivalent of ________ Earths.

Question 50

At room temperature,a population of dangerous bacteria on a piece of raw chicken increases from 100,000 to 400,000 in 40 minutes.During this period of exponential growth,the population doubles every ________ minutes.

Question 51

Exponential growth curves are always linear since the population grows at a constant proportion.

Question 52

Billions of people throughout the world currently consume insects and this number will likely increase if population growth trends continue upward.Consuming insects makes good sense for all of the following reasons EXCEPT

A) insects are highly nutritious with a protein content equal to conventional foods.
B) insects are abundant and typically have very high population growth rates.
C) insects can be grown, harvested, and processed with relatively little environmental impact.
D) consuming insects helps reduces their overall impact as pest organisms.

Question 53

Because of its shape,the curve describing population growth that occurs when a population grows exponentially is termed ________-shaped.

Question 54

A relationship between birth rate and population density exists,for example,in the plantain weed Plantago major; as densities increase,birth rates ________.

Question 55

When the combination of death and emigration rates is lower than the combination of birth and immigration rates,the population will ________.

Question 56

A population can increase in size indefinitely.

Question 57

Food production and consumption are not well matched throughout the world; preventing mass starvation would be possible if nontraditional food sources could be developed.One of the most promising,because they grow quickly and have a high protein content,is ________.

Question 58

Once a population reaches its carry capacity,its size will remain stable indefinitely.

Question 59

Population size is affected by both density-independent and density-dependent factors; daily weather is an example of a density-________ factor.

Question 60

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

Question 61

Although it happened long ago,the story of Easter Island should be of concern to modern man; in some ways,the Earth is like an island-all of its resources are confined by a boundary as significant as a shoreline.

Question 62

The approximate number of humans on Earth in 2012 is 7 billion.

Question 63

Pollution is one of the many density-dependent factors that can limit population growth.

Question 64

When an S-shaped growth curve levels,it is an indication that a population may have reached its carrying capacity and that at least one critical resource has become limiting.

Question 65

The carrying capacity of a habitat always remains the same.

Question 66

Humans appear to be the only species not subject to limits on the size of its population.

Question 67

Natural disasters can limit population growth in ways not related to population density.

Question 68

The carrying capacity of a population can be affected by weather,the daily fluctuations in temperature,rainfall,and the other factors that contribute to climate.

Question 69

Insects represent a highly nutritious and relatively inexpensive potential human food source.

Question 70

The ecological footprint of a typical college student in the United States is about the same as a typical college student at a university in China.