Deck 45: Population Ecology

Question 1

Every population has a characteristic

A)size.
B)density.
C)distribution.
D)number of individuals in its various age categories.
E)all of these.

Answer 1

E

Question 2

In 1722, a European explorer found __________ people on "Easter Island," starving and huddled in caves.

A)a few hundred
B)a few thousand
C)about 1 million
D)less than a dozen
E)none of these

Answer 2

A

Question 3

The distribution of the human population in the United States is

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

Answer 3

A

Question 4

The distribution of individuals in a school of fish is likely to be

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

Question 5

What distribution pattern is the most common in the natural world?

A)random
B)uniform
C)clumped
D)stratified or layered
E)homogeneous

Question 6

Random dispersion of individuals in a population occurs when habitat conditions are __________, resource availability is __________, and individuals or pairs of individuals __________ one another.

A)random; scarce; either attract or avoid
B)clumped; fairly steady; neither attract nor avoid
C)nearly uniform; random; neither attract nor avoid
D)nearly uniform; fairly steady; neither attract nor avoid
E)clumped; scarce; either attract or avoid

Question 7

Which of the following is NOT involved in capture-recapture methods of population sampling?

A)DNA fingerprinting
B)tags
C)collars
D)leg rings
E)wing markers

Question 8

Individuals in the population grouped according to levels of maturity define the population's

A)carrying capacity.
B)age structure
C)density.
D)size.
E)birth rate.

Question 9

Population size is related to

A)deaths.
B)births.
C)migration.
D)immigration.
E)all of these.

Question 10

The distribution of social animals is likely to be

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

Question 11

Which of the following provides a chicken rancher using a free-roaming arrangement for his flock the data necessary to ensure maximum survival of his hens?

A)distribution of chickens throughout the range
B)total number of chickens
C)chickens per square foot of the range
D)total square footage of the range
E)crude density of the chicken population

Question 12

The accuracy of the capture-recapture methods depends on all of the following EXCEPT that

A)marked individuals are recaptured at random.
B)unmarked individuals are captured at random.
C)none of the marked individuals are overlooked.
D)no marked individual dies or departs during the study.
E)no new individuals are produced during the study.

Question 13

The total number of individuals in a population is the population

A)distribution.
B)growth.
C)birth rate.
D)size.
E)age structure.

Question 14

Seasonal bird migration exemplifies

A)clumped dispersion.
B)uniform distribution.
C)random dispersion.
D)distribution over time.
E)all of these.

Question 15

The average number of individuals in a specified portion of habitat is the population's

A)distribution.
B)carrying capacity.
C)density.
D)size.
E)birth rate.

Question 16

Which of the following is NOT true regarding population counts?

A)A full population count is usually impractical.
B)Ecologists estimate a population's total density from a sample of the population.
C)Sampling within quadrats is particularly useful for most populations of migrating animals.
D)A full population count is possible for large animals in small areas.
E)Capture-recapture methods are used to estimate the population's size of species that do not "stay put."

Question 17

In 1440, there were approximately how many people living on Easter Island?

A)1 million
B)95,000
C)15,000
D)a few hundred
E)none of these

Question 18

Which of the following is true regarding quadrats?

A)A full population count is usually impractical.
B)Quadrats are plots of land of the same size and shape that can be used to randomly count a single non-migrating species.
C)Once several quadrats are counted, an estimate of number of a particular organism can be extrapolated for a given land mass.
D)Sampling error is common if the size of the quadrats is not large.
E)All of these are correct.

Question 19

The distribution of highly competitive animals is likely to be

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

Question 20

A population of wolf spiders exemplifies a __________ population distribution.

A)clumped
B)random
C)uniform
D)constant
E)homogeneous

Question 21

Zero population growth is achieved

A)when a population reaches the carrying capacity of the environment.
B)when emigration and immigration are balanced, and the number of births equals the number of deaths.
C)anytime that births exceed deaths.
D)anytime that deaths exceed births.
E)when emigration and immigration are prevented.

Question 22

The net reproduction per individual per unit time (r) is __________ per mouse per month in a population of 1,000 mice where 500 mice are born and 400 mice die monthly.

A)0.1
B)0.2
C)0.3
D)0.4
E)0.5

Question 23

If K (carrying capacity) for a population is 1,200, and r = 0.9, which of the following populations will show the greatest increase over the course of one year assuming exponential growth?

A)N = 100
B)N = 200
C)N = 300
D)N = 700
E)N = 900

Question 24

The size of a population is affected by all of the following EXCEPT

A)biotic potential.
B)trophic level.
C)carrying capacity of the environment.
D)death rate.
E)birth rate.

Question 25

What concept is used to express the growth rate of a given population?

A)doubling time
B)population density
C)population size
D)carrying capacity
E)biotic potential

Question 26

The change in population size is measured in terms of

A)birth rates.
B)death rates.
C)the number of individuals entering the population.
D)the number of individuals leaving the population.
E)all of these.

Question 27

All of the following may be involved in feedback mechanisms in natural communities when populations become too dense EXCEPT

A)density-dependent factors.
B)limiting factors.
C)biotic potential.
D)physical factors.
E)biotic factors.

Question 28

Limiting factors

A)produce more pronounced effects as a population grows.
B)prevent indefinite, exponential population growth.
C)can be either density-dependent or density-independent.
D)acting together constitute environmental resistance to population growth.
E)include all of these.

Question 29

When the birth rate plus immigration equals the death rate plus emigration the result is

A)logistic growth.
B)exponential growth.
C)population saturation.
D)zero population growth.
E)geometric growth.

Question 30

Populations

A)are only limited by one factor at a time.
B)increase arithmetically.
C)may increase indefinitely.
D)are limited by the carrying capacity.
E)overcome limiting factors by increasing their biotic potential.

Question 31

Which of the following is NOT true regarding biotic potential? It

A)varies from one species to another.
B)is related to the timing of the first reproduction.
C)is related to the frequency of reproduction.
D)is related to the number of offspring produced.
E)increases as population density increases.

Question 32

Biotic potential is controlled by all of the following factors EXCEPT

A)the age of individuals within the population.
B)the resources available for each individual.
C)fecundity rate.
D)environmental disturbances.
E)all of these control biotic potential.

Question 33

Which of the following is NOT true for a population growing exponentially?

A)The number of individuals added to the population in a year is greater than it was the previous year.
B)The population growth rate increases year after year.
C)Its r remains constant in the short-run.
D)The doubling time remains constant.
E)All of these are NOT true.

Question 34

The animal in the above photograph was adversely affected by __________ and is making a comeback thanks to __________.

A)global cooling; heat producing chemical added to their diet
B)sexually transmitted viruses; a new vaccine
C)limited number of natural cavities; artificial nesting boxes
D)high incidence of males being born; transplantation of females from other areas
E)all of these

Question 35

If K (carrying capacity) for a population is 1,200, and r = 0.1, which of the following populations will show the greatest increase over the course of one year assuming exponential growth?

A)N = 100
B)N = 200
C)N = 300
D)N = 700
E)N = 900

Question 36

A population of 1,000 individuals with an r = 1 per individual per year in an unlimited environment will number __________, four years later.

A)1,000
B)1,004
C)4,000
D)16,000
E)40,000

Question 37

There will be approximately __________ mice in four months in a population of 1,000 mice where 500 mice are born and 400 mice die monthly.

A)1,060
B)1,160
C)1,260
D)1,360
E)1,460

Question 38

As population density increases, the chance of __________ also increases.

A)parasitism
B)disease
C)predation
D)competition
E)all of these

Question 39

The effect of resource availability on population size determines

A)the carrying capacity of the environment.
B)exponential growth.
C)the doubling time of a population.
D)the population's biotic potential.
E)all of these.

Question 40

Recurring travel between two distinct destinations is

A)migration.
B)cyclic emigration.
C)emigration.
D)immigration.
E)cyclic immigration.

Question 41

Type II survivorship curves

A)are characteristic of humans and elephants.
B)indicate a fairly constant rate of death at all ages.
C)indicate a high mortality rate in the very young.
D)are characteristic of species in which most individuals live a relatively long life and die of old age.
E)are typical of species with high biotic potentials.

Question 42

Questions refer to the figure above illustrating logistic growth.

The population is in exponential growth at

A)A.
B)B.
C)C.
D)D.
E)E.

Question 43

Life tables provide data concerning

A)expected life span.
B)reproductive age.
C)death rate.
D)birth rate.
E)all of these.

Question 44

A cohort is

A)a group of individuals of the same species born during the same time interval.
B)any member of the same species.
C)a group of individuals with the same parents.
D)a group of individuals of the same sex.
E)any group of closely related individuals.

Question 45

The factors that tend to reduce the size of a population regardless of its initial size are

A)density-dependent factors.
B)density-independent factors.
C)ecological factors.
D)biotic factors.
E)species-independent factors.

Question 46

Reznick and Endler were interested in the effects of __________ on guppy evolution.

A)predation
B)competition
C)population density
D)density-independent factors
E)mating rituals

Question 47

The carrying capacity of an environment is determined by the

A)net rate of reproduction of the female members of the population.
B)population's logistic growth.
C)number of reproductively capable individuals in the population.
D)population's biotic potential.
E)sustainable supply of resources it provides.

Question 48

Which density-dependent factor affects the size of a population?

A)wind velocity
B)light intensity
C)nutrient supply
D)rainfall
E)humidity

Question 49

Which of the following is NOT true regarding guppies of the species Poecilia reticulata?

A)Males are generally smaller than the females.
B)Males are more brightly colored than the females.
C)Males continue growing after reaching sexual maturity.
D)The male's colors serve as visual signals for mating.
E)They have complex mating rituals.

Question 50

Questions refer to the figure above illustrating logistic growth.

The effect of population growth limiting factors begin to become evident at about

A)A.
B)B.
C)C.
D)D.
E)E.

Question 51

A J-shaped population growth curve becomes an S-shaped one

A)as more resources become available.
B)if the data are plotted on semi-log graph paper.
C)as the carrying capacity is reached.
D)if reproduction stops.
E)if any of these occur.

Question 52

A type III survivorship curve is characteristic of all of the following EXCEPT

A)flies.
B)primates.
C)frogs.
D)sea stars.
E)fish.

Question 53

Organisms that demonstrate type I survivorship are characterized by

A)high r, small offspring.
B)low r, small offspring.
C)low r, large offspring.
D)high r, large offspring.
E)low r, large population size.

Question 54

A type III survivorship curve is characteristic of

A)cattle.
B)horses.
C)eagles.
D)sea urchins.
E)humans.

Question 55

Questions refer to the figure above illustrating logistic growth.

N is equal to the initial carrying capacity at

A)A.
B)B.
C)C.
D)D.
E)E.

Question 56

Density-independent factors that limit population growth include

A)parasites.
B)temperature.
C)disease.
D)competition.
E)predation.

Question 57

Questions refer to the figure above illustrating logistic growth.

The initial carrying capacity of an environment is indicated by

A)A.
B)B.
C)C.
D)D.
E)E.

Question 58

The work of Reznick and Endler with guppies shows all of the following EXCEPT that

A)life history traits can be inherited.
B)life history traits evolve.
C)life history traits can be altered over a short period of time.
D)predation does not influence the modification of life history traits.
E)life history traits are coded for in DNA.

Question 59

A study of a cohort of 1,000 animals showed a 90 percent death rate per individual in the first year, 10 percent the second year, and 5 percent the third year.This population's survivorship is

A)type I.
B)type II.
C)type III.
D)type I the first year and type II in years two and three.
E)type I the first year, type II the second year, and type III the third year.

Question 60

Questions refer to the figure above illustrating logistic growth.

A change in the environment's long-term ability to sustain the population is indicated by

A)A.
B)B.
C)C.
D)D.
E)E.

Question 61

Killifish and pike-cichlids raised in natural conditions will

A)affect the age at first reproduction of the guppies that live with them.
B)prey on guppies.
C)affect the growth rate of guppies.
D)affect the evolution of the guppies' life history traits.
E)do all of these.

Question 62

All EXCEPT which one of the following are the reasons for the rapid population explosion of humans?

A)increases in carrying capacity
B)expansion into new habitats
C)removal of limiting factors
D)reproduction occurring earlier in the life cycle
E)None of these