Deck 34: Growth of Populations

Question 1

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 8 individuals.
C) The population of owl prey organisms will increase proportionately.
D) A short-term exponential growth of owls will occur.

Answer 1

B

Question 2

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 2

D

Question 3

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

Answer 3

D

Question 4

The decrease in the availability of food or cover that accompanies increasing population size illustrates the concept of a

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

Question 5

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.

Question 6

Nene, the Hawaiian goose, live on Maui. Their population density is .164 per square kilometer. Maui is 1,830 square kilometers in size. Approximately how many nene live on Maui?

A) 16
B) 150
C) 300
D) 11,600

Question 7

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

A) Herd A
B) Herd B
C) Herd C
D) Herd D

Question 8

The human population crash that occurred on Easter Island was due to

A) fire.
B) expanding forests and the consequent loss of farmland.
C) the aftermath of a volcanic eruption.
D) deforestation, soil erosion, and resource depletion.

Question 9

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 10

Which of the following has the smallest contribution to annual changes in the size of a population?

A) weather
B) predators
C) climate
D) disease

Question 11

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 12

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

Question 13

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 14

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 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

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 17

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 two years?

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

Question 18

The size of a population can be decreased by

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

Question 19

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

A) They do not yet have any natural predators in their new habitat.
B) Most introduced species show better survival in new habitats than in their old ones.
C) Since 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 20

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 21

The initial success of a human civilization

A) is typically characterized by decreases in population density.
B) simply postpones its inevitable collapse.
C) does not guarantee its future existence.
D) has no effect on population factors.

Question 22

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 23

Examine the graph below.
What statement best describes the relationship between planting density and seed production per individual plant?

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

Question 24

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 25

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 26

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

A) all of the animals in the San Diego Zoo
B) Gause's paramecia without a constant food supply
C) a founding colony of rats on a small island with abundant resources
D) a beehive infected mid-summer with a deadly bacterial disease

Question 27

The current rate of human population growth is

A) not sustainable.
B) sustainable.
C) a tightly linked cycle.
D) fairly low.

Question 28

What was the effect of the pesticide DDT on bald eagles?

A) They lost the ability to fly.
B) The animals they ate as prey were killed by the DDT.
C) Their eggs were fragile, breaking before the chicks could develop fully.
D) The trees they lived in were killed by the DDT.

Question 29

Which of the following does not provide evidence that resources needed by humans are unsustainable?

A) fish population
B) water tables
C) logging
D) fertilizer use

Question 30

The human population is very good at

A) growing.
B) consuming energy.
C) controlling its growth.
D) a and b above

Question 31

When an isolated population reaches its carry 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 32

The rate of human population growth has not yet leveled off because

A) the human population experiences a greater number of births than deaths each year.
B) humans are using resources more rapidly than they are replenished, a pattern of resource use that allows the population to temporarily increase but that cannot be sustained.
C) humans use technology to increase the carrying capacity of the places where they live.
D) all of the above

Question 33

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 while 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: density-dependent and density-independent factors cannot affect the same population of organisms at the same time.

Question 34

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 35

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 36

A vector is a term used to describe an organism that moves a disease organism from one host to another. What is the vector associated with the encephalitis caused by West Nile virus?

A) field mice
B) mosquitoes
C) feral cats
D) wild birds

Question 37

The graph below 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 38

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 were 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 39

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 40

Which of the following statements best describes what will happen to the human population if it continues to increase exponentially?

A) A population crash when natural resources can no longer support the number of people on Earth.
B) A gradual conversion to the S-shaped growth curve and eventual stabilization of population size.
C) The tightly linked cycle between humans and our predators will become less obvious.
D) The irregular fluctuations in human population size will begin to reach greater extremes.

Question 41

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

Question 42

A population grows as more of its individuals emigrate.

Question 43

_______ growth occurs when the population size increases by a constant proportion from one generation to the next.

Question 44

Use of the environment that can continue indefinitely without depleting all our resources or causing environmental damage is defined as being _______.

Question 45

Population size _______ when the combination of death and emigration rates are lower than the combination of birth and immigration rates.

Question 46

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

Question 47

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

Question 48

A __________ is a group of interacting individuals of the same species living within the same area.

Question 49

In natural systems, populations do not change in size when birth + immigration = death + emigration.

Question 50

A population can increase in size indefinitely.

Question 51

Exponential growth curves are always J-shaped.

Question 52

Overall, when there are more individuals in a population, birth rates _______.

Question 53

A _______-shaped curve describes population growth that occurs when a population grows exponentially.

Question 54

___________ growth occurs when a population increases by a constant proportion from one generation to the next.

Question 55

When an S-shaped growth curve levels it is an indication that a population may have reached its carrying capacity.

Question 56

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

Question 57

Food shortages and communicable disease are examples of factors that would _______ a population's growth rate.

Question 58

The carrying capacity of a population can be affected by weather.

Question 59

Populations generally change in size over time.

Question 60

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 61

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

Question 62

The approximate number of humans on Earth is 7 billion.

Question 63

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

Question 64

Humans could be described as an invasive species.

Question 65

The carrying capacity of a habitat always remains the same.