Deck 13: Interspecific Competition

Question 1

The Russian biologist G.F.Gause was one of the first to support the Lotka-Volterra equations by studying the competitive interactions of ________ species.

Answer 1

Paramecium

Question 2

________ competition results when nonterritorial behavioral interactions between two species result in negative effects on both species.

Answer 2

Encounter

Question 3

Interspecific competition involves individuals of two or more species vying for the same limited ________.

Answer 3

resource

Question 4

Chemical interaction competition in plants is called ________.

Question 5

The Lotka-Volterra equations predict the outcomes of ________ competition under different conditions.

Question 6

A shift in the morphology,behavior,or physiology of a species in response to resource competition is referred to as ________ displacement.

Question 7

In the following formula,what is β? dN₂/dt = r2N₂(1 - (N₂ + βN₁)/K2)

A)competition coefficient
B)growth rate
C)carrying capacity
D)population size

Question 8

Chemicals released by plants to inhibit germination and establishment of other species is known as

A)consumption.
B)allelopathy.
C)toxicopathy.
D)competitive exclusion.

Question 9

A taller plant shading those individuals below,and reducing available light,is referred to as

A)preemptive competition.
B)consumption competition.
C)overgrowth competition.
D)territorial competition.

Question 10

When a species expands its niche in response to the removal of a competitor,the species has experienced competitive ________.

Question 11

The portion of the fundamental niche that an organism actually exploits in the presence of competitors is called its ________ niche.

Question 12

Interspecific ________ occurs when the competition for space between two species influences access to food and nesting sites.

Question 13

Various species of scavengers fighting over the carcass of a dead animal is referred to as

A)consumption competition.
B)preemptive competition.
C)encounter competition.
D)overgrowth competition.

Question 14

Periods of drought or extreme environmental conditions may depress the ________ of a species below its carrying capacity (K).

Question 15

A relationship that affects the populations of two or more species adversely is referred to as ________ competition.

Question 16

According to the competitive ________ principle,two "complete competitors" cannot coexist.

Question 17

The coexistence of competitors due to differences in the range of resources used or environmental tolerances is referred to as niche ________.

Question 18

The occupation of space by a sessile organism,such as a barnacle,that precludes the establishment or occupation by another species is referred to as

A)preemptive competition.
B)consumption competition.
C)overgrowth competition.
D)encounter competition.

Question 19

What is a zero-growth isocline?

A)when the population size of species 1 exceeds species 2
B)the set of values where α = β
C)the set of values of two population sizes where the growth rate is 0
D)the set of values where the carrying capacity is reached for one of the two species

Question 20

________ competition results when individuals of one species inhibit individuals of another by using up a shared resource.

Question 21

Species A prefers a more dry habitat but grows in a wet habitat.Why might this be?

A)Species B outcompetes A in the dry habitat.
B)Species A's fundamental niche is restricted to a wet habitat.
C)Species A requires large amounts of moisture to grow.
D)Species B prefers a wet habitat.

Question 22

The different chipmunk species correspond to the different tree species along an elevational gradient.This is likely because

A)each chipmunk species depends on the specific tree species for habitat.
B)lodgepole trees and lodgepole chipmunks prefer warmer temperatures.
C)the fundamental niche of yellow-pine chipmunks is limited to middle elevation.
D)several resource factors for both groups change with elevation.

Question 23

Two bird species compete in the forest for the same seeds.If α = 0.75 and β = 0.25,then (assuming the same carrying capacity for both)

A)the rate of seed consumption is the same for both species.
B)the environment can supply both species since the sum of competition coefficients equals 1.
C)species 1 "wins" and will outcompete species 2.
D)species 2 "wins" and will outcompete species 1.

Question 24

The competitive exclusion principle assumes that the

A)competing species have different resource requirements.
B)competing species have the same carrying capacity (K).
C)environmental conditions remain constant.
D)superior competing species will have a lower population growth rate than the inferior competitor.

Question 25

How can one grass species be dominant one year,while another is dominant a few years later and then the first becomes dominant again?

A)changes in precipitation across years
B)Lotka-Volterra models predicting cycling
C)competitive exclusion principle
D)growth rate differences among the species

Question 26

In Tilman's experiments with diatoms,what was the outcome when the two species competed for silica?

A)Both coexisted.
B)Both survived several years but one eventually won out.
C)One outcompeted the other to extinction.
D)Both died.

Question 27

Which of the following is TRUE regarding competition?

A)One species will always drive the other to extinction.
B)Competition is always focused on food.
C)The species larger in size typically outcompetes the smaller.
D)Water temperature can influence the outcome of competitive interactions.

Question 28

Paramecium aurelia has a higher rate of population growth and can tolerate a higher population density than P.caudatum.When both species were introduced into a tube containing a fixed amount of bacterial food,the populations of both species

A)thrived,even though they shared the same food supply.
B)initially increased,after which P.aurelia thrived and P.caudatum died out.
C)initially increased,after which P.caudatum thrived and P.aurelia died out.
D)died out.

Question 29

Typically species compete for

A)food.
B)space.
C)essential nutrients.
D)multiple resources simultaneously.

Question 30

According to the figure,when these two species are combined in a culture,what will the outcome be?

A)P)aurelia wins.
B)P)caudatum wins.
C)Both species coexist.
D)P)aurelia wins only if it starts at a higher abundance.

Question 31

Which of the following is a nonresource (or nonconsumable resource)that can influence the outcome of competition among plant species?

A)temperature
B)light
C)water
D)nitrogen

Question 32

If the carrying capacity of species 2 was actually 50,what would the competitive outcome be?

A)Both species coexist.
B)Species 1 wins.
C)Species 2 wins.
D)Both species go extinct.

Question 33

The diagonal line that represents dN/dt = 0 in the graphical depiction of the Lotka-Volterra competitions equations is called

A)a competition coefficient.
B)the carrying capacity.
C)a zero-growth isocline.
D)a competitive exclusion parameter.

Question 34

According to the competitive exclusion principle,the populations of two species that live in the same place and have exactly the same ecological requirements

A)can coexist at the same carrying capacity (K)as when each population is separate.
B)can coexist but with the population of each species at half of the carrying capacity (K)as when each population is separate.
C)can coexist but with the population of one species much higher than that of the other species.
D)cannot coexist because one species will eventually drive the other to extinction.

Question 35

The competitive exclusion principle states that

A)one species will always win out.
B)two species cannot coexist unless they cooperate.
C)two close competitors cannot coexist.
D)one species will feed on another until it is extinct.

Question 36

What is the outcome of these isoclines?

A)Species 2 wins.
B)If species 1 begins with a higher abundance,it wins.
C)If species 2 begins with a higher abundance,it wins.
D)Species 1 wins.

Question 37

Two organisms using a portion of the same resource simultaneously is referred to as

A)niche overlap.
B)competitive release.
C)intraspecific competition.
D)territoriality.

Question 38

What is the outcome of these isoclines?

A)Species 1 wins.
B)If species 1 begins with a higher abundance,it wins.
C)Species 2 wins.
D)Both species coexist.

Question 39

According to the Lotka-Volterra equations,which of the following is not an expected outcome of competitive interactions between two species?

A)Species 1 drives species 2 to extinction.
B)Species 2 drives species 1 to extinction.
C)Both species coexist.
D)The populations of both species increase to infinity.

Question 40

Hiking up an elevational gradient,you notice different species of birds becoming more dominant the higher you go.This could be because

A)older birds prefer lower elevations.
B)competitive abilities change along environmental gradients.
C)of population cycling.
D)there are more predators at higher elevation.

Question 41

According to the Lotka-Volterra equations,when two species compete for the same resource,one or the other species eventually wins,driving the other to extinction.

Question 42

Coexisting species of wild cats differ in the size of their canine teeth,which corresponds to differences in their preferred species of prey.This outcome is most likely the result of

A)resource partitioning.
B)ecological release.
C)competitive exclusion.
D)preemptive competition.

Question 43

One way two competing species can coexist in the same area is via

A)having the same competition coefficient.
B)zero-growth isoclines.
C)competitive exclusion.
D)niche differentiation.

Question 44

Competition typically

A)only involves two closely related species.
B)involves a predator and prey.
C)is a complex interaction of biotic and abiotic factors.
D)is random.

Question 45

Competition for one resource often influences the ability of an organism to access other resources.

Question 46

The outcome of competitive interactions is determined solely by resource availability.

Question 47

Coyote populations are lower where wolf populations are increasing because

A)wolves directly compete with coyotes.
B)wolves are a primary predator on coyotes.
C)wolves can withstand colder temperatures than coyotes.
D)wolves facilitate coyote populations by leaving scavenged meat.

Question 48

Laboratory studies have confirmed that two different species can coexist while using the same resource.

Question 49

Competitive release is most likely to occur when a

A)species colonizes an island that already has potential competitors.
B)species moves into new habitats that it never occupied on a mainland.
C)species decreases in abundance.
D)competing species is added to a community.

Question 50

Changes in the outcome of competition over an environmental gradient are mediated by multiple environmental variables.

Question 51

Change in beak size over time in Darwin's finches is an example of

A)environmental gradient.
B)fundamental niche.
C)competitive exclusion.
D)character displacement.

Question 52

Environmental variation can allow competitors to coexist where under constant conditions one would exclude the other.

Question 53

Encounter competition results from the behavioral exclusion of some individuals by others from a specific space that is defended.

Question 54

The portion of potential resources and conditions that an organism actually exploits as a result of interactions with other species is its

A)home range.
B)territory.
C)realized niche.
D)fundamental niche.

Question 55

One effect of decreasing wolf populations in North America is

A)decreased deer populations.
B)range expansion for coyotes.
C)range retraction for elk.
D)increased bear populations.

Question 56

Climatic variation can function as a density-independent limitation on population density.

Question 57

The competitive exclusion principle assumes that the competing species have exactly the same resource requirements.

Question 58

Competition has been regarded as a major force behind species divergence and specialization.

Question 59

Demonstrating the occurrence of interspecific competition during a field study is problematic for all of the following reasons,except

A)it is difficult to know whether a population is at carrying capacity.
B)competition is impossible to measure in a natural setting.
C)scientists cannot control the environment.
D)scientists lack full knowledge of the life history requirements of natural populations.

Question 60

Preemptive competition occurs primarily among mobile organisms,such as small mammals.

Question 61

Differences among species may relate to adaptation for the ability to exploit a certain environment or range of resources independent of competition.

Question 62

Removing individuals during a competition experiment may have direct and indirect effects on the environment that are not intended or understood by the investigators and that can influence the response of the remaining species.

Question 63

Two or more organisms using a portion of the same resource simultaneously is referred to as resource partitioning.

Question 64

Because of interspecific competition,species do not always occupy the part of their fundamental niche where conditions yield the highest growth rate,reproduction,or fitness.

Question 65

Studying competition in the laboratory is more complex than studying competition in the field.