Deck 36: Population Ecology

Question 1

A Type I survivorship curve is associated with which of the following life history traits?

A)infant mortality being much greater than adult mortality
B)large numbers of offspring being produced
C)a short life span for most individuals
D)parents providing extended care for their young

Answer 1

D

Question 2

A survivorship curve that involves producing very few offspring,each of which has a high probability of surviving to adulthood,is typical of

A)sea stars.
B)elephants.
C)rodents.
D)oysters.

Answer 2

B

Question 3

A group of individuals of a single species that occupy the same general area defines a

A)community.
B)population.
C)subspecies.
D)clone.

Answer 3

B

Question 4

The human population on Earth is expected to reach 9.5 billion people by

A)2015.
B)2093.
C)3150.
D)2050.

Question 5

A newly mated queen ant establishes an ant nest in an unoccupied patch of suitable habitat.The population of the nest grows quickly at first,then levels off at carrying capacity.Which of the following types of equation will best describe its population growth?

A)linear
B)logistic
C)exponential
D)logarithmic

Question 6

The density of Douglas firs in an old- growth forest is estimated by counting the Douglas firs in four sample plots of 1 hectare each.The number of fir trees in the plots is 10,12,7,and 11,respectively.What is the estimated density of firs in the forest?

A)20 trees per hectare
B)10 trees per hectare
C)25 trees per hectare
D)5 trees per hectare

Question 7

An ecological footprint

A)measures dispersion and adaptability.
B)will estimate population movements.
C)is a means of understanding resource availability and usage.
D)is a means of determining increases in populations that lived in the past.

Question 8

Which of the following is an example of a population?

A)all students attending colleges and universities in your state
B)the various plants found in prairies in the western United States
C)all of the students in your classroom
D)all of the microorganisms on your skin

Question 9

If a population has a birth rate of 40 individuals per 1,000 per year and a death rate of 30 individuals per 1,000 per year,how will the population change each year? (Assume that the population is below carrying capacity and that there is no immigration or emigration.)

A)It will increase by 1%.
B)It will decrease by 70%.
C)It will increase by 5%.
D)It will increase by 100%.

Question 10

Guppies from Trinidad form two distinct populations that differ in several life history traits that appear to relate to the local predator populations,pike- cichlids or killifish.Which of the following experiments would test the heritability of these traits?

A)Provide additional food to the guppies from cichlid habitats to see if they will grow to the same size as guppies from the killifish habitat.
B)Introduce cichlids into a habitat with killifish.
C)Raise both populations without predators to see if they maintain their life history traits.
D)Raise both populations with cichlids to see if the population of smaller,faster- maturing guppies reproduces more quickly.

Question 11

Consider a stable frog population living at carrying capacity in a pond.If an average female produces 6,000 eggs during her lifetime and an average of 300 tadpoles hatch from these eggs,how many of these tadpoles will,on average,survive to reproduce?

A)2
B)more than 100
C)10 to 20
D)0

Question 12

An ecologist hypothesizes that predation by a particular owl species is the major factor controlling the population of a particular rabbit species.The first step in testing this hypothesis would be to determine

A)whether the owls eat the rabbits.
B)what food the rabbits eat.
C)whether populations of the rabbit that live outside the range of the owl have higher population densities.
D)to which diseases the rabbit population is subject.

Question 13

A demographic tool used to predict a population's future growth is

A)demographic transition.
B)age structures.
C)maximum sustained growth.
D)a hairline growth curve.

Question 14

If an ecosystem has a carrying capacity of 1,000 individuals for a given species,and 2,000 individuals of that species are present,we can predict that the population

A)size will slowly increase.
B)size will remain at equilibrium.
C)size will decrease.
D)will show a clumped dispersion pattern.

Question 15

According to this graph of population growth in Mexico,in what year was the rate of population increase in Mexico the greatest?

A)1912
B)1965
C)2000
D)1930

Question 16

Which of the following statements about insecticides is true?

A)To control agricultural pests,pest management uses biological controls,chemicals,or cultural methods,but never a combination of these.
B)Prey species often have a higher reproductive rate than do predators.
C)Simply killing many individuals is often the best way to reduce the size of a pest population.
D)Most insecticides kill the pest but not the pest's natural predators.

Question 17

An ecologist hypothesizes that predation by a particular owl species is the major factor controlling the population of a particular rabbit species.If this is the case,which of the following population effects could be expected in this rabbit- owl pair?

A)An increase in the owl population should cause a fall in the rabbit population.
B)An increase in the incidence of disease in the rabbit population should not change the owl population.
C)A fall in the rabbit population should cause an increase in the owl population.
D)A fall in the owl population should cause a fall in the rabbit population.

Question 18

To obtain optimal production in a small garden,one should

A)sow seeds randomly throughout the garden.
B)plant seeds in a uniform pattern throughout the garden.
C)plant seeds in rows with minimal spacing between rows.
D)plant seeds in clumps with large spaces between clumps.

Question 19

An r- selected species typically

A)offers considerable parental care to offspring.
B)is large- bodied and long- lived.
C)has an advantage in habitats that experience unpredictable disturbances.
D)lives in stable climates.

Question 20

In the logistic growth model,as population size increases,birth rates

A)remain constant and death rates increase.
B)decline and/or death rates increase.
C)and death rates increase.
D)decline but death rates remain steady.

Question 21

The death by bubonic plague of about one- third of Europe's population during the fourteenth century is a good example of

A)abiotic factors limiting population size.
B)a density- independent effect.
C)a density- dependent effect.
D)carrying capacity.

Question 22

You drive through Iowa in the spring and notice that along a stretch of several kilometers,every third fence post has a male redwing blackbird perched on it defending its nesting territory.This is an example of

A)clumped dispersion.
B)uniform dispersion.
C)random dispersion.
D)artificial dispersion.

Question 23

What is the age structure of a population?

A)the difference in the age distribution of a population at two different points in time
B)the proportion of individuals in different age groups
C)the curve that results when the likelihood of being alive is plotted as a function of age
D)the curve that results when the likelihood of dying is plotted as a function of age

Question 24

Which of the following is most clearly a case of density- dependent population regulation?

A)the occurrence of rainstorms for an opportunistic desert annual
B)the first hard frost of fall for a population of annual morning glory vines
C)the summer drying of savanna grass for an insect that feeds on grass sap
D)a dangerous new flu strain that is transmitted among humans by sneezing

Question 25

According to this graph of the population growth of fur seals,in what year did the population first reach its carrying capacity?

A)1950
B)1940
C)1930
D)1925

Question 26

Which of the following will likely decrease a population's size?

A)decreasing the food supply available to the population
B)practicing sustainable resource management in its habitat
C)improving the quality of its habitat
D)increasing the size of its habitat

Question 27

A population of fungi in a yard produces 10 mushrooms in year 1,20 in year 2,and 40 in year 3.If this trend continues,by year 5 there will be mushrooms.

A)40
B)80
C)320
D)160

Question 28

Which of the following statements about human population growth is true?

A)Human population size has increased faster and faster throughout human history.
B)Human population size on Earth today is at equilibrium.
C)Demographic transition is a transition from high birth rates and high death rates to low birth rates and low death rates.
D)During a demographic transition,birth rates typically drop first due to the availability of reliable contraception.

Question 29

Which of the following organisms best illustrates K- selection?

A)a polar bear producing one or two cubs every three years
B)a species of weed that quickly spreads into a region of cleared trees
C)the production of thousands of eggs every spring by frogs
D)mice that produce three litters of 10- 15 babies in the course of a summer

Question 30

A survivorship curve is a

A)model for population growth that incorporates the concept of carrying capacity.
B)graph that plots an individual's likelihood of being alive as a function of age.
C)graph that plots an individual's likelihood of reproducing as a function of age.
D)graph that shows the effect of predation on a prey population.

Question 31

A tidal wave wipes out the entire population of mice living on an island.This is an example of

A)the effects of abiotic factors.
B)a density- dependent effect.
C)Type III survivorship.
D)the interaction between density- dependent and abiotic factors.

Question 32

The pattern of distribution for a certain species of kelp is clumped.We would expect that the pattern of distribution for a population of snails that live on the kelp would be

A)clumped.
B)uniform.
C)random.
D)homogeneous.

Question 33

A human population will achieve zero population growth if

A)the birth rate equals the intrinsic rate of increase r.
B)couples have an average of about 2.25 children each (to account for some children who do not survive to reproduce).
C)no couple has more than two children.
D)no couple has more than one child.

Question 34

The world human population

A)is growing faster now than ever before.
B)has leveled off at carrying capacity.
C)is growing,but at a slower rate than in the last century.
D)is starting to decline.

Question 35

Assume that there are five alligators per acre in a swamp in northern Florida.This is a measure of the alligator population's

A)intrinsic rate of increase.
B)dispersion.
C)range.
D)density.

Question 36

In terms of population dynamics,what is "boom- and- bust" cycling?

A)a situation in which a population moves back and forth between rapid growth and decline
B)a situation in which the sex ratio in a population shows repeated oscillations
C)a situation in which a growing population overshoots the carrying capacity of its environment and experiences a crash before stabilizing
D)a situation in which the populations of a predator species and a prey species oscillate in unison

Question 37

A test tube is inoculated with 1 × 103 cells of a bacterial strain that has a generation time of 30 minutes.The carrying capacity of the test tube for this strain is 6 × 109 cells.What will the bacterial population be after 90 minutes of culturing?

A)1 × 10¹² B)1 × 10⁹ C)3 × 10³ D)8 × 10³

Question 38

Which of the following statements about human demographic trends is true?

A)After 1950,mortality rates increased rapidly in most developing countries.
B)A human population in which women reproduce at an later age will experience slower population growth.
C)As women's status and education increase,they choose to have more children.
D)The movement from high birth rates and low death rates to low birth rates and high death rates is called the demographic transition.

Question 39

The age structure of the United States in 2010 shows

A)a broad base,suggesting a low birth rate.
B)a broad base,suggesting a high birth rate.
C)that the United States has not yet gone through a demographic transition.
D)that a greater proportion of the population is elderly now than in earlier decades.

Question 40

The maximum number of individuals a habitat can support is called its

A)reproductive potential.
B)density- dependent factor.
C)carrying capacity.
D)community size.

Question 41

If most of the individuals of a human population are in their pre- reproductive years,you would expect the population size to after 20 years.

A)stay the same
B)decrease and then stabilize
C)increase
D)decrease