Ecology Chapter 13

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.

One outcompeted the other to extinction

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.

P. aurelia wins

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.

wolves directly compete with coyotes

In a competitive interaction in which species 1 has a higher carrying capacity (K1) than species 2 (K2), it is expected that species ________ will go extinct.

2

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.

Both species coexist

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.

Both species coexist

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

Consumptive

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

Encounter

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

Paramecium

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.

Species 1 wins

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.

Species B outcompetes A in the dry habitat

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.

The populations of both species increase to infinity

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.

Water temperature can influence the outcome of competitive interactions

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.

cannot coexist because one species will eventually drive the other to extinction

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

changes in precipitation across years

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

character

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.

competitive abilities change along environmental gradients

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.

a zero-growth isocline

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

realized

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.

realized niche

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

release

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.

initially increased, after which P. aurelia thrived and P. caudatum died out

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

interspecific

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

interspecific

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.

is a complex interaction of biotic and abiotic factors

Typically species compete for A) food. B) space. C) essential nutrients. D) multiple resources simultaneously.

multiple resources simultaneously

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.

niche differentiation

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.

niche overlap

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.

overgrowth competition

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

population

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.

preemptive competition

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.

range expansion for coyotes

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

resource

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.

resource partitioning

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.

several resource factors for both groups change with elevation

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.

species 1 "wins" and will outcompete species 2.

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.

species moves into new habitats that it never occupied on a mainland

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

temperature

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

territoriality

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

the set of values of two population sizes where the growth rate is 0

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.

two close competitors cannot coexist

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.

character displacement

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

competition coefficient

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.

competition is impossible to measure in a natural setting

Chemical interaction competition in plants is called ________.

allelopathy

Chemicals released by plants to inhibit germination and establishment of other species is known as A) consumption. B) allelopathy. C) toxicopathy. D) competitive exclusion.

allelopathy

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

differentiation

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.

encounter competition

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.

environmental conditions remain constant

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

exclusion