Ecology Homework Final

Your page rank:

Total word count: 10882
Pages: 40

Calculate the Price

- -
275 words
Looking for Expert Opinion?
Let us have a look at your work and suggest how to improve it!
Get a Consultant

Which of the following statements about biological communities is true?

A. Trade-offs faced by individual community members have little impact on community structure.

B. Species interactions have only minor impacts on community structure.

C. Experiments that focus on interactions among a small number of species are likely to overestimate the importance of species’ interactions in structuring communities.

D. Fundamental niches represent a primary constraint on the species present in a community.

E. Intraspecific competition often results in the exclusion of species from a community.

D. Fundamental niches represent a primary constraint on the species present in a community.

The biological structure of a community is first constrained by the __________ of the species.

a. realized niches
b. competitive interactions
c. fundamental niches
d. trophic interactions
e. direct interactions

c. fundamental niches

Which of the following statements about zonation is FALSE?

a. Competition is the only biological factor that influences patterns of zonation.

b. Regional patterns of plant distributions are largely driven by climate.

c. Zonation is the result of variation in resources and non-resource factors.

d. Zonation can be a product of the trade-off between the ability to tolerate stress and competitive ability.

e. Salinity is a major gradient that influences zonation in estuaries.

a. Competition is the only biological factor that influences patterns of zonation.

When sea otters are removed from kelp communities of the northeastern Pacific Ocean, the kelp are quickly overgrazed by sea urchins, which are a favorite food of otters. Thus, the entire community structure changes. This is an example of __________.
View Available Hint(s)

a. succession

b. apparent competition

c. intraguild predation
the intermediate

d. disturbance hypothesis

e. keystone predation

e. keystone predation

Researchers are studying a community in Alaska with a number of herbivores (A-F) as well as quite a few carnivores (G-K). They find that when they remove herbivore A from the experimental community, there is little effect on the population of carnivores in later years while herbivores B-F increase slightly in number. However, when they remove herbivore D from the population there is a decrease in all predators (G-K) and a slight decrease in other herbivores as well. Which of the following conclusions could you make about this community?

a. Herbivore A is a very good competitor with diffuse connections to most other herbivores. Herbivore D is a very important prey source to predators G-K.

b. Herbivore A is a critical prey source for the predators G-K.

c. There are only direct interactions in this community.

d. Predators G-K all consume herbivores A-F.

e. Herbivore D is a good competitor, but is not an important prey source.

a. Herbivore A is a very good competitor with diffuse connections to most other herbivores. Herbivore D is a very important prey source to predators G-K.

As an example of an indirect interaction, a predator may __________ the population density of one or more inferior competitors by __________ the abundance of the superior competitor, which is the predator’s main prey.

a. reduce, increasing

b. Not affect, indirectly reducing.

c. increase, reducing

d. indirectly reduce, directly reducing

e. directly increase, indirectly reducing

c. increase, reducing

Part A Part complete
An indirect positive or beneficial interaction of two species within a community is an example of __________.

a.indirect competition

b. indirect mutualism

c. mutualism

d. keystone predation

e. indirect commensalism

b. indirect mutualism

In a rocky intertidal community where starfish are absent, mussels outcompete all other species. However, when starfish are present, they reduce mussel populations, and other invertebrates, including some that are not eaten by starfish, are able to persist in the community. The interaction between the starfish and the other invertebrates that they do not consume is an example of __________.

a. apparent competition.

b. indirect commensalism

c. intraguild predation

d. a bottom-up effect

e.indirect mutualism

b. indirect commensalism

Which of the following statements about food webs is true?

a. More-complex food webs tend to have greater community stability.

b. The structure of food chains suggests that the productivity and abundance of populations at any given trophic level are unrelated to the productivity and abundance of populations in the trophic level below them.

c. Analyzing trophic levels is a complex approach to studying food webs.

d. Studying the trophic interactions as functional groups tends to mask the influence of species diversity on the structure of a community.

e. Bottom-up control always occurs without any top-down control.

a. More-complex food webs tend to have greater community stability.

Hairston, Smith, and Slobodkin first introduced the concept of __________ control with the frequently quoted "the world is green" proposition.

a. food web

b. trophic cascade

c. top-down

d. bottom-up

e. food chain

c. top-down

Which of the following statements about environmental heterogeneity is FALSE?

a. Grasslands have higher bird species diversity than forests.

b. Indices of habitat complexity are good predictors of species diversity in many cases.

c. Increased vertical structure leads to increased bird diversity in forests.

d. Burrowing animals can increase species diversity in communities by creating microhabitat variation in soil characteristics.

e. The death of canopy trees can increase species diversity in forests.

a. Grasslands have higher bird species diversity than forests.

Choose the system below that is likely to have the highest species diversity in terms of vegetation and bird species.

a. a climax forest with uniform soil depth and very few disturbances

b. a desert ecosystem with limited water availability and patchy vegetation

c. a highly stratified forest with limited variable resources and intermediate disturbances

d. A young forest with moderate stratification, few disturbances, and that has high levels of nutrients.

e. a grassland with few vegetative layers

c. a highly stratified forest with limited variable resources and intermediate disturbances

Saying that a trait or competitive ability is size asymmetric means that __________.

a. plants grow more on one side than on another

b. plants will grow more roots than shoots when expressing that trait

c. the plant may grow to different maximum sizes depending on the environment in which it is grown.

d. the plant will reproduce without genetic recombination

e. larger plants have a disproportionate advantage in competition, resulting in initial size differences being compounded over time

e. larger plants have a disproportionate advantage in competition, resulting in initial size differences being compounded over time

Wolf reintroduction in Yellowstone decreased elk populations due to predation. Researchers have found that this has led to __________.

a. a decline in beaver populations due to increased predation by wolves

b. no effect on aspen trees as they are not the primary food of elk

c. an increase in berry-producing shrubs and a positive impact on invertebrate species that feed on these berries

d. a purely negative impact on the grizzly bear population in Yellowstone

e. a regrowth of willow trees that led to a decrease in bird species diversity

c. an increase in berry-producing shrubs and a positive impact on invertebrate species that feed on these berries

Which of the following is an example of a fundamental niche?

a. an amphibian laying eggs in all possible habitats

b. a lizard feeding on insects only at dawn when snakes are present

c. a bird nesting on top of a tree in the presence of predators

d. a mouse feeding on only small seeds in the presence of a competitor

a. an amphibian laying eggs in all possible habitats

There is considerable evidence that community structure is influenced by interactions between species.

a. True

b. False

a. True

What might one expect to see in a graph depicting realized niche space in a community?

a. one dominant species utilizing all of the resources

b. each species utilizing its full resources

c. large overlap between species resource use

d. reduced overlap between species resource use

d. reduced overlap between species resource use

In looking at a distribution map you see an empty space where habitat conditions are suitable for that species. Why might that exist?

a. The species has a limit to population growth.

b. That species prefers other areas.

c. The space is due to the null model.

d. Other species outcompete it in that space.

d. Other species outcompete it in that space.

Environmental conditions often vary spatially but do not tend to change over time in a given place.

a. True

b. False

b. False

Competition among plant species rarely involves only a single resource.

a. True

b. False

a. True

What happens to the species Chthamalus stellatus when Balanus balanoides is removed from the lower intertidal zone?

a. Chthamalus is able to survive in the lower intertidal zone.

b. Balanus switches habitat to the upper intertidal zone.

c. Chthamalus survives worse.

d. There is no change in distribution for either species.

a. Chthamalus is able to survive in the lower intertidal zone.

In comparison to the upper intertidal zone, species in the lower intertidal zone are more apt to

a. have a lower metabolic rate.

b. have lower resource requirements.

c. be better competitors.

d. be desiccation tolerant.

c. be better competitors.

A competitive plant growing in wet conditions would be predicted to have

a. many leaves and stems.

b. low metabolic rate.

c. a larger root system.

d. high tolerance to water stress.

a. many leaves and stems.

Diffuse competition is __________.

a. competition in which no competitor "wins"

b. competition that is not negative for all competitors

c. direct competition of weak individuals

d. the total competitive effects of a number of interspecific competitors

e. competition in a population with a great deal of immigration and emigration

d. the total competitive effects of a number of interspecific competitors

Diffuse interactions often occur among competing species but never among predator-prey species.

a. True

b. False

b. False

Which is an example of a diffuse species interaction?

a. Removal of one beetle species from a community shows no effect.

b. Canada lynx cause population cycling in snowshoe hares.

c. Loss of starfish results in mussel outcompeting other species.

d. Removal of sea otters results in kelp forest depletion.

a. Removal of one beetle species from a community shows no effect.

A diffuse species interaction infers the effects of

a. predation is stronger than those of competition.

b. predation by one species on another is strong.

c. competition by one species on another is strong.

d. competition by one species on another is weak.

d. competition by one species on another is weak.

What is a misconception about the Canada lynx and snowshoe hare cycling?

a. Canada lynx are the only predators on snowshoe hares.

b. Snowshoe hare populations vary over time.

c. Rodents compete with snowshoe hares for grasses.

d. Snowshoe hares impact resource abundance.

a. Canada lynx are the only predators on snowshoe hares.

This pyramid shows the ratio of organisms, energy content, and biomass at different trophic levels.

Suppose that a system has 5000 grasshoppers. How many hawks would be expected?

a. 5

b. 50

c. 500

d. 5000

b. 50

How is energy transferred from one trophic level to the next? Select all that apply.

a. heat loss

b. herbivory

c. predation

d. parasitism

e. cellular respiration

b. herbivory c. predation d. parasitism

Indirect interactions can be either positive or negative for the affected species.

a. True

b. False

a. True

The removal of a single species from a community can have unpredictable consequences.

a. True

b. False

a. True

When apparent competition occurs, the

a. populations of predator and prey species are larger.

b. populations of predator and prey species are smaller.

c. population of the predator species is larger and the populations of the prey species are smaller.

d. population of the predator species is smaller and the populations of the prey species are larger.

c. population of the predator species is larger and the populations of the prey species are smaller.

Which of the following communities could exhibit apparent competition?

a. species with diffuse interactions

b. species that do not share either resources or a predator

c. species the share resources but not a predator

d. species that share a predator but not resources

d. species that share a predator but not resources

What is the term when one species benefits from an indirect interaction and the other has a neutral effect?

a. indirect mutualism

b. indirect commensalism

c. indirect competition

d. mutualism

b. indirect commensalism

Increasing the resources for one species results in the increase of predator numbers. This reduces the abundance of another prey species. This interaction is

a. apparent predation.

b. indirect commensalism.

c. indirect mutualism.

d. apparent competition.

d. apparent competition.

The control of an herbivore population by a parasitoid is an example of top-down control.

a. True

b. False

a. True

The "world is green" hypothesis suggests that herbivore populations limit the number of predators, allowing plant biomass to accumulate.

a. True

b. False

b. False

When top-down control occurs within an intertidal zone along the rocky coastline of the Pacific Ocean, which of the following species controls the abundance of other species?

a. starfish

b. mussels

c. kelp

d. barnacles

a. starfish

Food webs are typically arranged into trophic levels with

a. primary producers at the bottom, carnivores in the middle, and herbivores at the top.

b. primary producers at the bottom, herbivores in the middle, and carnivores at the top.

c. herbivores at the bottom, carnivores in the middle, and primary producers at the top.

d. carnivores at the bottom, herbivores in the middle, and primary producers at the top.

b. primary producers at the bottom, herbivores in the middle, and carnivores at the top.

When bass were removed from a stream, an algal bloom occurred. This is an example of

a. apparent competition.

b. the null model.

c. top-down control.

d. bottom-up control.

c. top-down control.

Removal of sea otters from a system results in a massive increase in sea urchins and subsequent loss of kelp beds. This is an example of

a. indirect mutualism.

b. a trophic cascade.

c. bottom-up control.

d. apparent competition.

b. a trophic cascade.

The "world is green" hypothesis advocates which mechanism?

a. the null model

b. top-down control

c. diffuse competition

d. bottom-up control

b. top-down control

Environmental heterogeneity tends to be positively correlated with species diversity.

a. True

b. False

a. True

The diversity of an animal community is unrelated to the physical structure of a plant community.

a. True

b. False

b. False

Given large differences in moisture retention in soils, what would you predict?

a. increased community diversity

b. more similar functional types in the community

c. no effect on community diversity

d. decreased community diversity

a. increased community diversity

What does this figure suggest?

a. Increased foliage height diversity drives increased bird diversity.

b. Decreased foliage height diversity drives increased bird diversity.

c. There is no relationship between foliage height and bird diversity.

d. Increased bird diversity drives increased foliage height diversity.

a. Increased foliage height diversity drives increased bird diversity.

As the degree of environmental heterogeneity of a community increases, the number of plant and animal species tends to

a. increase initially and then
decrease.

b. remain the same.

c. increase.

d. decrease.

c. increase.

As the fertility of soil on the forest floor increases, the

a. size of plants decreases.

b. growth rate of plants increases.

c. number of species of plants increases.

d. density of plants decreases.

b. growth rate of plants increases.

Why might increased soil fertility result in lower species diversity?

a. There is no relationship between soil fertility and species diversity.

b. Dominant species are less able to outcompete other species.

c. Dominant species are better able to outcompete other species.

d. Increased nutrients help more rare plants survive.

c. Dominant species are better able to outcompete other species.

In Yellowstone National Park, the reintroduction of wolves has led to

a. increased fruit consumption in elk.

b. a decrease in deciduous tree growth.

c. a decrease in the elk population.

d. an increase in the elk population.

c. a decrease in the elk population.

Which of the following organisms have benefited from wolf reintroduction?

a. grizzly bears

b. woody plant species

c. beavers

d. all of the above

d. all of the above

A(n) __________ is a group of species that occupy an area and may interact directly or indirectly.

a. population

b. family

c. metapopulation

d. community

e. ecosystem

d. community

Based on the data given above, which of the following statements is FALSE?

a. The Australian grasslands have lower species evenness than the African plains.

b. The seagrass habitat has the lowest species richness.

c. The diversity (D) of African plains and Australian grasslands is the same.

d. The African plains and Australian grasslands have identical species richness.

e.The seagrass habitat has the highest species evenness.

c. The diversity (D) of African plains and Australian grasslands is the same.

Rank abundance is __________.

a. the community ranking based on species evenness, ranked from the least to the most abundant

b. the number of different species

c. the species ranking based on relative abundance, ranked from the most to the least abundant

d. the species ranking based on relative abundance, ranked from the least to the most abundant

e. the community ranking based on species evenness, ranked from the most to the least abundant

c. the species ranking based on relative abundance, ranked from the most to the least abundant

Relative abundance is calculated by __________.

a. multiplying the species richness by the species evenness

b. multiplying the total number of individuals of all species in a community by the total number of individuals of a given species

c. dividing the total number of each of the species in the community by the total number of individuals of all species and then adding each of these numbers together for a single value for the whole community

d. dividing the total number of individuals of the species of interest by the total number of individuals of all species present in the community

e. dividing the total number of individuals of all species present in the community by the total number of individuals of the species of interest

d. dividing the total number of individuals of the species of interest by the total number of individuals of all species present in the community

Simpson’s index of diversity ranges between __________ and __________, with __________ values indicating greater diversity.

a. 0, 1, lower

b. 0, species evenness of a community, higher

c. 0, species evenness of a community, lower

d. 0, 1, higher

e. -1, 1, higher

d. 0, 1, higher

The Shannon index is a widely used index of biological diversity. The lowest possible value for this index is __________, and the highest possible value is __________.

a, -1, 1

b. 0, 1

c. 0, the number of species found in that community

d. 0, 10

e. 0, the natural log of the species richness

e. 0, the natural log of the species richness

You find a forest with a few different tree species: maple, oak, hickory, and tulip polar. You determine that the maples are abundant in the understory, and the hickories have the largest biomass. Which of the following statements can you make about this forest?

a. The hickories are clearly the only dominant species, as they have the greatest biomass.

b. The dominance of this forest is four.

c. The maples and the hickories are possible dominant species, depending on how you are analyzing the structure of the forest.

d. There is not a dominant species in the forest, as there is species diversity, and dominance requires a species diversity of zero with one dominant.

e. The maple is clearly the dominant species, as it is the most abundant.

c. The maples and the hickories are possible dominant species, depending on how you are analyzing the structure of the forest.

The removal of a keystone species from a community will initiate changes in that community’s structure and typically results in __________.

a. a significant loss of diversity

b. unpredictable changes in diversity

c. a significant increase in diversity

d. no significant change in diversity

e. no change in diversity or abundance of species

a. a significant loss of diversity

In a food web, an example of an intermediate species is __________.

a. algae

b. an herbivore

c. a primary producer

d. an autotroph

e. a top carnivore

b. an herbivore

In a food web, organisms can be grouped based on how they obtain their energy. These groupings are called __________.

a. web groups

b. functional groups

c. guilds

d. trophic levels

e. feeding stages

d. trophic levels

Which of the following statements about community structure is FALSE?

a. Coastal marine communities are defined based on their plant life.

b. Terrestrial communities are often classified by their dominant plant life.

c. Communities have a vertical structure.

d. Community structure can reflect abiotic factors.

e. Open-ocean communities are defined largely by the amount of light that penetrates to a particular depth.

a. Coastal marine communities are defined based on their plant life.

Which of the following statements about the physical structure of communities is FALSE?

a. Most photosynthesis in a temperate lake occurs in the hypolimnion of the lake.

b. Light penetration influences stratification in aquatic communities.

c. An understory will develop below the canopy if there is ample light and nutrients.

d. Decomposition in a forest occurs mainly on the forest floor.

e. The forest canopy is the site of greatest photosynthesis.

a. Most photosynthesis in a temperate lake occurs in the hypolimnion of the lake.

Which of the following statements about sandy beach communities is FALSE?

a. Zonation of the intertidal zone is dominated by heterotrophic organisms rather than autotrophs.

b. Patterns of species distribution are related to tides.

c. Most intertidal organisms are burrowing species, which helps them avoid large temperature fluctuations and desiccation.

d. The supratidal zone is the area above the high-tide line, where most animals are able to tolerate high degrees of desiccation.

e. Almost no species moves between the zones of sandy beaches.

e. Almost no species moves between the zones of sandy beaches.

Which of the following statements is true?

a. There is a standard sampling strategy for analyzing communities.

b. Typically, a community has distinct boundaries indicating where it ends and another community begins.

c. The definition of what constitutes a distinct community is entirely objective.

d. The spatial scale at which sampling occurs can influence what is considered a unique community.

e. Community names based on a single species are an indication of low species diversity.

d. The spatial scale at which sampling occurs can influence what is considered a unique community.

The __________ concept of communities suggests that communities are simply assemblages of species that have similar environmental requirements.

a. holistic

b. assemblage

c. integration

d. organismic

e. continuum

e. continuum

Which of the following statements about restoration ecology is FALSE?

a. Lake restoration involves reducing inputs of nutrients from the surrounding land.

b. More intensive restoration involves re-creating the community from scratch.

c. The least intensive restoration effort involves the rejuvenation of existing communities.

d. An important aspect of restoration ecology is to eliminate all disturbances and keep the natural communities as stable as possible.

e. Wetland restoration may involve reestablishing the hydrological conditions so that the wetland is flooded at the appropriate time of year as well as the replanting of aquatic plants.

d. An important aspect of restoration ecology is to eliminate all disturbances and keep the natural communities as stable as possible.

In order to reconstruct natural communities as part of restoration, many critical ecological questions must be answered. All of the following are important questions involved in restoration of ecological communities with one exception. Choose the exception.

a. How do the component species interact with each other?

b. Are all species equally important to the functioning and persistence of the community?

c. How does the community’s size influence the number of species it can support?

d. How do different communities on the larger landscape interact?

e. How can invasive species be integrated into the natural community?

e. How can invasive species be integrated into the natural community?

In a rank-abundance curve comparing two communities, the community with the greater species richness is characterized by a

a. lesser length of the curve and a more gradual slope.

b. greater length of the curve and a more gradual slope.

c. lesser length of the curve and a steeper slope.

d. greater length of the curve and a steeper slope.

b. greater length of the curve and a more gradual slope.

Communities with low evenness will have rank-abundance curves

a. that are 1:1.

b. that are very shallow.

c. that are flat.

d. that are very steep.

d. that are very steep.

The relative abundance of a tree with 100 individuals in a community of 1000 would be

a. 0.1.

b. 100.

c. 1.

d. 10.

a. 0.1.

When an ecologist compares the diversity of different communities by counting the number of species within each community, the measure of diversity being used is called

a. relative abundance.

b. species richness.

c. species diversity.

d. species evenness

b. species richness.

Which of the following has the highest species richness? A community with

a. 35 species of high evenness.

b. 36 species with very low evenness.

c. 34 species of high evenness.

d. 33 species of low evenness.

b. 36 species with very low evenness.

Most communities have many common species and a few rare species.

a. True

b. False

b. False

Which is the most dominant species?

a. most relative biomass

b. largest in number

c. highest in relative abundance

d. All of the above can indicate dominance.

d. All of the above can indicate dominance.

The removal of a keystone species from a community typically results in an increase of diversity.

a. True

b. False

b. False

Which statement best describes a keystone species?

a. a rare or uncommon species that has a strong effect on its community

b. a species that takes up a great deal of space in a community

c. an abundant species that may or may not affect other species

d. a common species that has a strong effect on its community

a. a rare or uncommon species that has a strong effect on its community

A species that has massive effects on an ecosystem but in proportion to its abundance is a

a. top predator.

b. basal species.

c. keystone species.

d. dominant species.

d. dominant species.

What might be a result of hunting sea otters to extinction for their fur?

a. loss of sea urchins

b. loss of killer whales

c. loss of barnacles

d. loss of kelp beds

d. loss of kelp beds

In the following community, which serves as the keystone species?

a. sea otters

b. kelp bed

c. sea urchins

d. killer whales

a. sea otters

A food web is more complicated than a food chain.

a. True

b. False

a. True

The garter snake in this diagram is an example of a(n)

a. herbivore.

b. intermediate species.

c. top predator.

d. basal species.

b. intermediate species.

The species within a guild are unlikely to interact with one another.

a. True

b. False

b. False

Which of the following groups of species represents a guild?

a. species of plants that use the C3 pathway of photosynthesis

b. species of plants or animals that are iteroparous

c. species of plants that tolerate shade

d. species of birds that feed on nectar

d. species of birds that feed on nectar

Which of the following is considered a guild?

a. mammals

b. top predators

c. insect-feeding birds

d. coniferous forest

c. insect-feeding birds

The form and structure of terrestrial communities are defined more by the plants than the animals present.

a. True

b. False

a. True

In a well-stratified lake, the thermocline refers to a steep and rapid decline in temperature relative to the waters above and below.

a. True

b. False

a. True

The aphotic zone of a lake is inhabited primarily by phytoplankton.

a. True

b. False

b. False

In a forest community, the layer in which most photosynthesis occurs is the

a. midstory.

b. canopy.

c. understory.

d. forest floor.

b. canopy.

The layer of a forest in which decomposition takes place and mineral nutrients are released for reuse by plants is called the

a. herb layer.

b. understory.

c. canopy.

d. forest floor.

d. forest floor.

Zonation within a community is typically the result of differences in the

a. rates of reproduction among species within a community.

b. patterns of competition among species within a community.

c. patterns of predation among species within a community.

d. physical characteristics of the environment across a spatial gradient.

d. physical characteristics of the environment across a spatial gradient.

In a sandy beach community, ghost crabs and beach flies occur within

a. the intertidal zone.

b. the subtidal zone.

c. any tidal zone.

d. the supratidal zone.

d. the supratidal zone.

In which of the following zones would you most likely expect to find flounders (a type of fish)?

a. supratidal

b. subtidal

c. intertidal

d. salt meadow

b. subtidal

The boundaries between communities are usually sharply defined and easily discerned.

a. True

b. False

b. False

The organismic concept views communities as clusters of species associating together as an interacting, integrated component.

a. True

b. False

a. True

An ecologist samples the abundance of various species along an environmental gradient and fails to find clusters of species. Instead, peaks of abundance of dominant species are merely randomly spaced segments along a continuum. This distribution of species supports the

a. successional concept of a community.

b. organismic concept of a community.

c. individualistic or continuum concept of a community.

d. unified concept of a community.

c. individualistic or continuum concept of a community.

An organismic concept of communities was developed by

a. Gleason.

b. Shannon.

c. Clements.

d. Simpson.

c. Clements.

The goal of restoration ecology is to

a. return the community to its pre-disturbance condition.

b. restore the use of ecosystem services.

c. create the most functional ecosystem.

d. improve productivity in an ecosystem.

a. return the community to its pre-disturbance condition.

Who was Aldo Leopold?

a. a statistician

b. a hunter

c. a conservationist

d. a marine biologist

c. a conservationist

Which of the following is an induced predator defense?

a. reduced foraging when predators are present

b. warning coloration

c. protective armor of an armadillo

d. cryptic coloration of a snowshoe hare.

e. mimicry

a. reduced foraging when predators are present

__________ is an evolved prey defense mechanism that makes them visually obvious but also serves to warn a potential predator of the prey’s toxicity or other chemical defenses.

a. Cryptic coloration

b. Müllerian coloration

c. Flashing coloration

d. Aposematism

e. Batesian mimicry

d. Aposematism

The type of mimicry in which a harmless mimic resembles a dangerous model is called __________.

a. warning mimicry

b. aposematic mimicry

c. induced mimicry

d. Müllerian mimicry

e. Batesian mimicry

e. Batesian mimicry

An organism that feeds on plant or algal tissues is referred to as a(n)

a. herbivore.

b. decomposer.

c. carnivore.

d. omnivore.

a. herbivore.

Scavengers are heterotrophs.

a. True

b. False

a. True

A true predator is a species that

a. feeds only on animals.

b. kills its prey more or less immediately upon capture.

c. feeds on dead or living prey.

d. feeds upon any part of any organism, not necessarily killing it.

b. kills its prey more or less immediately upon capture.

Grazers and browsers are true predators.

a. True

b. False

b. False

Which of the following is functionally a true predator?

a. parasite

b. planktivore

c. parasitoid

d. grazer

b. planktivore

A parasitoid

a. is a true predator.

b. attacks the host indirectly by laying its eggs in or on the prey’s body.

c. preys only on animals.

d. actively pursues its prey.

b. attacks the host indirectly by laying its eggs in or on the prey’s body.

Some animals acquire their toxic chemical compounds from plants that they consume.

a. True

b. False

a. True

Acoustic mimicry by some nonvenomous snakes that rattle their tails like rattlesnakes is a form of Müllerian mimicry.

a. True

b. False

b. False

If you are stranded on a desert island, which prey should you avoid consuming?

a. brightly colored prey

b. large prey

c. cryptic prey

d. fast mobile prey

a. brightly colored prey

All three of these species are harmful. This is an example of

a. functional response.

b. optimal foraging theory.

c. Müllerian mimicry.

d. Batesian mimicry.

c. Müllerian mimicry.

Which of the following is an example of cryptic coloration?

a. snakes with black, yellow, and red bands

b. a brown bird that nests on the ground

c. a deer with a large, white tail

d. skunks with black and white stripes

b. a brown bird that nests on the ground

When prey produce so many offspring in a short period of time that predators can attack only a fraction of them, it is referred to as

a. a numerical response.

b. a functional response.

c. cryptic reproduction.

d. predator satiation.

d. predator satiation

In a graph that plots prey population (Nprey) on the x-axis against the number of predator offspring produced per unit of time on the y-axis, the slope represents the

a. efficiency with which food is converted into predator population growth or reproduction (b).

b. predator population growth rate (r).

c. efficiency of predation (c).

d. the rate of increase in prey availability.

a. efficiency with which food is converted into predator population growth or reproduction (b).

In the basic Lotka-Volterra equations that describe predator-prey interactions, the growth rate of the prey population (dNprey/dt) is zero when the density of predators (Nprey) is equal to

a. r/N.

b. N/r.

c. c/r.

d. r/c.

d. r/c.

The net outcome of predator-prey interactions in the basic Lotka-Volterra models is that

a. predator and prey populations eventually converge on equilibrium population sizes that are maintained into infinity.

b. the prey population declines and this causes the predator population to also decline.

c. predator and prey populations oscillate, with each predictably increasing and decreasing in response to the other.

d. the predator drives its prey to extinction and then goes extinct itself.

c. predator and prey populations oscillate, with each predictably increasing and decreasing in response to the other.

Part A Part complete
In a basic Lotka-Volterra predator-prey model, what happens if predator and prey populations are graphed in relation to time?

a. They begin to cycle.

b. Predators eat all of the prey.

c. The predator population crashes.

d. Nothing happens; the populations stay the same through time.

e. They return to the equilibrium point.

a. They begin to cycle.

What do you observe about the relative timing of the peaks in lynx numbers and hare numbers?

a. Hare numbers typically peaked slightly before lynx numbers.

b. Lynx numbers typically peaked slightly before hare numbers.

c. Hare numbers and lynx numbers typically peaked at the same time.

d. There is no relationship between when hare numbers peaked and when lynx numbers peaked.

a. Hare numbers typically peaked slightly before lynx numbers.

What might explain the observation that hare numbers typically peaked slightly before lynx numbers?

a. Both lynx and hare populations peak when weather is mild and food is plentiful, and both populations crash during severe weather.

b. The peaks in the lynx population result in heavy predation of the hares, causing the hare population to crash soon after.

c. Both hare and lynx populations naturally go through regular cycles, and in this pair of populations, the hares peak slightly before the lynxes by chance.

d. The lynx depend on the hares for food, but there is a delay between increased food availability and increased reproduction by the lynx.

d. The lynx depend on the hares for food, but there is a delay between increased food availability and increased reproduction by the lynx.

In a simple experiment involving only predator and prey with no refuge,

a. predators will typically drive their prey to extinction.

b. prey will always survive.

c. prey populations will oscillate.

d. both populations will oscillate.

a. predators will typically drive their prey to extinction.

Huffaker’s experiment involving oranges showed

a. predators will always consume prey to extinction.

b. with enough complexity, predator and prey populations will oscillate.

c. prey will always outlast predators.

d. both species use oranges for refuge.

b. with enough complexity, predator and prey populations will oscillate.

The Lotka-Volterra equations for predator and prey populations suggest __________.

a. unpredictable population dynamics

b. no substantial interactions between predator and prey populations

c. prey regulation of predator populations only

d. predator regulation of prey populations only

e. predator regulation of prey populations and prey regulation of predator populations

e. predator regulation of prey populations and prey regulation of predator populations

In the Lotka-Volterra model of predator-prey interactions, population growth is regulated through

a. reproduction for the predator and mortality for the prey.

b. reproduction for the prey and mortality for the predator.

c. reproduction for both predator and prey.

d. mortality for both predator and prey.

a. reproduction for the predator and mortality for the prey.

__________ developed the classification scheme for predator functional responses.

a. E. Charnov

b. C. S. Holling

c. V. Volterra

d. A. Lotka

e. M. E. Solomon

b. C. S. Holling

The response of a predator’s consumption rate to prey density is a key factor as to whether a predator can regulate a prey population.

a. True

b. False

a. True

A Type I functional response leads to regulation of the prey population by the predator.

a. True

b. False

b. False

A Type III functional response is the most commonly reported for predators.

a. True

b. False

b. False

One explanation for the shape of the Type II functional response is that predators develop a search image for prey after they have encountered them.

a. True

b. False

b. False

When a predator drives down a prey population to a low abundance, it will often

a. consume prey to extinction.

b. go extinct.

c. decrease handling time of prey.

d. switch prey species.

d. switch prey species.

The sigmoidal relationship between prey density and per capita predation rate in a Type III functional response can be explained by all of the following factors, except

a. predator density.

b. recognition of prey by predator.

c. predator preference.

d. prey access to refuge.

a. predator density.

With a highly abundant prey population size, which component of the functional response is most reduced?

a. handling time

b. search time

c. prey population

d. killing time

b. search time

The numerical increase in predators due to the movement of predators into areas of high prey density (immigration) is called __________.

a. the reproductive response

b. the foraging response

c. the immigration response

d. the functional response

e. the aggregative response

e. the aggregative response

This figure shows that

a. lynx become better able to capture prey over time.

b. hares will go extinct over time.

c. lynx become worse at capturing prey over time.

d. lynx populations numerically respond to hare populations.

d. lynx populations numerically respond to hare populations.

A small bird travels to a foraging patch and then begins collecting seeds. All of the following factors influence how long it spends in the patch with one exception. Choose the exception.

a. the rate of metabolism of the bird eating the seeds

b. the amount of time spent traveling to the patch

c. the quality of the patch relative to other patches in the environment

d. the presence of competitors in the foraging patch

e. the presence of predators in the patch

a. the rate of metabolism of the bird eating the seeds

A predator encounters four prey types at equal rates. The energy content and handling times for each prey type are A (100, 10), B (80, 9), C (200, 25), and D (50, 4). From the predator’s perspective, what is the order of profitability of these prey types from best to worst?

a. D, A, B, C

b. D, B, C, A

c. C, A, B, D

d. A, B, C, D

e. D, B, A, C

a. D, A, B, C

The total time spent foraging can be divided into two categories of activity: __________ and ____________.

a. avoiding detection and searching

b. searching and handling

c. stalking and searching

d. handling and eating

e. searching and hunting

b. searching and handling

The amount of time an organism spends foraging must be balanced against other time constraints, such as defense, avoiding predators, searching for mates, or caring for young.

a. True

b. False

a. True

It is difficult to quantify the consequences of a specific behavioral choice on the probability of survivorship and reproduction.

a. True

b. False

a. True

The profitability of a prey item

a. increases as its handling time (Th) increases.

b. increases as its energy content (E) decreases.

c. increases as its E/Th increases.

d. decreases as its search time (Ts) decreases.

c. increases as its E/Th increases.

The risk of predation can sometimes have a significant impact on the foraging choices made by animals.

a. True

b. False

a. True

Which of the following statements about predator-prey coevolution is FALSE?

a. Natural selection should produce more elusive prey.

b. The Red Queen hypothesis describes the coevolutionary race between predators and prey in which predators evolve faster than prey.

c. Natural selection should produce more efficient predators.

d. To survive as a species, prey evolutionary change in response to predators is necessary.

e. Failure to capture prey reduces fitness of predators.

b. The Red Queen hypothesis describes the coevolutionary race between predators and prey in which predators evolve faster than prey.

As prey species evolve more effective means to avoid being caught, predators evolve more effective means to capture them.

a. True

b. False

a. True

According to the Red Queen hypothesis,

a. the population density of a predator depends on the population density of its prey.

b. natural selection should favor the most efficient foragers.

c. most predators consume a varied diet in order to meet their nutritional requirements.

d. prey must continually evolve means of avoiding capture to avoid extinction.

d. prey must continually evolve means of avoiding capture to avoid extinction.

Cryptic coloration is a strategy employed only by prey.

a. True

b. False

b. False

Which of the following hunting methods has the lowest frequency of success but requires the least amount of energy?

a. stalking

b. satiation

c. pursuit

d. ambush

d. ambush

Quantitative inhibitors in plants are toxic secondary compounds, often causing herbivores to avoid their consumption.

a. True

b. False

b. False

Some plants are able to attract beneficial insects that act as predators on the herbivores of that plant.

a. True

b. False

a. True

Quantitative inhibitors

a. reduce digestibility of plant material.

b. include cyanide and alkaloids.

c. are toxic to herbivores.

d. are produced in small quantities by a plant.

a. reduce digestibility of plant material.

Carnivores can have an indirect, positive effect on plants by reducing populations of herbivores.

a. True

b. False

a. True

Which of the following is considered a nonlethal effect of predation?

a. reduced competition

b. reduced activity of prey

c. prey consumption

d. increased predator mortality

b. reduced activity of prey

The cod fisheries were able to be harvested beyond their ability to recover because __________.

a. the Cod fisheries were tightly regulated, with catch limits imposed on all fishing vessels

b. the Canadian and U.S. governments excluded all foreign fisheries in a zone extending 200 miles around the habitat

c. Cod were caught by large commercial trawlers with purse nets enabling a very high level of removal

d. when the number of cod declined, humans switched to fishing for other species

e. the cod that were harvested were of post-reproductive age, thus having little affect on the overall population growth

c. Cod were caught by large commercial trawlers with purse nets enabling a very high level of removal

What is maximum sustainable yield?

a. the size of a population of a given species that an environment can support

b. the yield that allows for populations to recover to their pre-harvest levels

c. a strategy that involves optimizing harvest of a particular species by keeping the population at an intermediate level and harvesting the species at a rate equal to the annual growth rate

d. the total number of new
individuals in a population of a species that is being used as a food product

e. the amount of resources harvested per unit of time

c. a strategy that involves optimizing harvest of a particular species by keeping the population at an intermediate level and harvesting the species at a rate equal to the annual growth rate

The ideal number of fish to catch to provide the most yield while sustaining fisheries is

a. at K/2.

b. dN/dt.

c. rN(1 – N/K).

d. at K.

a. at K/2.

Which of the following caused massive declines in U.S. commercial fish populations?

a. huge factory trawlers

b. freak weather events in the 1980s

c. foreign commercial fisherman

d. recreational anglers

a. huge factory trawlers

Which of the following statements is FALSE?

a. Preemptive competition occurs primarily among sessile organisms.

b. Allelopathy in plants is a form of chemical competition.

c. Consumption competition involves individuals of one species inhibiting another through consumption of a common resource.

d. In overgrowth competition, one species limits another’s access to a resource by growing over it.

e. Encounter competition is the behavioral exclusion of others from a specific defended space.

e. Encounter competition is the behavioral exclusion of others from a specific defended space.

Which of the following is an example of allelopathy?

a. The barnacle Balanus outcompetes Chthamalus everywhere except in the upper intertidal zone, where it is subjected to desiccation.

b. Some genes in a caterpillar become detrimental when a new parasitoid wasp invades the habitat.

c. The California sage, Salvia, uses chemicals to inhibit the growth of competitive plants.

d. Lions and wild dogs compete for Thompson’s gazelles, but lions also kill wild dogs.

e. Darwin’s finches possess different beak depths, depending on whether they co-occur.

c. The California sage, Salvia, uses chemicals to inhibit the growth of competitive plants.

Which of the statements below accurately reflects the assumptions of the competitive exclusion principle?

a. The competitive exclusion principle makes no assumptions about the competitors.

b. The competitive exclusion principle assumes that competitors have different resource requirements and that environmental conditions remain constant.

c. The competitive exclusion principle assumes that the competitors have resource partitioning and that environmental conditions remain constant.

d. The competitive exclusion principle assumes that the competitors have the exact same resource requirements and that environmental conditions may be variable.

e. The competitive exclusion principle assumes that the competitors have the exact same resource requirements and that environmental conditions remain constant.

e. The competitive exclusion principle assumes that the competitors have the exact same resource requirements and that environmental conditions remain constant.

The alpha and beta terms represent the __________ in the Lotka-Volterra models of population growth.

a. competition coefficients

b. energetic efficiencies

c. intrinsic growth rates

d. population sizes

e. death rates

a. competition coefficients

In the Lotka-Volterra equations, the competition coefficients represent __________.

a. the total effect of an individual of one species on members of its own species

b. the total effect that an individual of one species has on another species

c. the per capita effect that an individual of one species has on another species

d. the effect that a competing species has on another species, raising the effective carrying capacity

e. the per capita effect of an individual of one species on members of its own species

c. the per capita effect that an individual of one species has on another species

Resource partitioning over a long period can result in natural selection that causes a shift in features of the species’ morphology, behavior, or physiology. This is called __________.

a. character displacement

b. overgrowth

c. competitive exclusion

d. allelopathy

e. competition characters

a. character displacement

Which of the following statements is true?

a. Multiple species tend to perform their best under the exact same conditions.

b. Temperature, humidity, and salinity have little effect on competition.

c. Germination rates vary among species, but these differences do not translate into differences in competitive ability.

d. The outcome of competition can be influenced by factors other than limited resources.

e. Plants with high growth rates under high light conditions tend to be overgrown quickly in newly opened habitat patches.

d. The outcome of competition can be influenced by factors other than limited resources.

Which of the following is an example of shifting competitive ability due to temporal changes?

a. Plants growing at different altitudes on a mountain have varying ranges of water requirements.

b. An island is prone to drought every five to six years. The dominant bird species will switch during drought years and rainy years.

c. A variety of species grow in a field, with some species competing well in one area and other species competing well in another area. When the soil is examined, it is found to have patches of different limiting nutrients that correlate to different species successes.

d. Two species grow in a salt marsh. One species only grows in the low marsh near the creek, and the other grows further inland.

e. A community of trees is infected by a parasite that alters the competitive ability of the dominant species.

b. An island is prone to drought every five to six years. The dominant bird species will switch during drought years and rainy years.

Which of the following statements is true?

a. Plants engage in competition with other plants only through their shoots (stems and leaves).

b. Competition among plants is over one resource at a time.

c. Interspecific territoriality can influence access to multiple resources at one time.

d. The presence of animals has little effect on competition among plants.

e. Plants engage in competition with other plants only through their roots.

c. Interspecific territoriality can influence access to multiple resources at one time.

Which of the following statements about disturbance and competition is FALSE?

a. In plants, the relative growth rates (ln RR) of competitors could be used as an index of competition.

b. Disturbance can reverse the dominance in a competitive interaction by modifying the abiotic environment.

c. Disturbance will reduce competition by reducing variability in the environment.

d. Disturbance can cause the competitive landscape to shift through time.

e. Disturbance can reduce competition by removing competitively dominant species.

c. Disturbance will reduce competition by reducing variability in the environment.

The __________ is the full range of conditions and resources that a species can exploit when free from interference by other species.

a. actual niche

b. competitive niche

c. realized niche

d. fundamental niche

e. basic niche

d. fundamental niche

The __________ describes the range of conditions and resources that a species exploits as a result of interactions with other species.

a. realized niche

b. basic niche

c. fundamental niche

d. competitive niche

e. actual niche

a. realized niche

Which of the following statements is true?

a. Natural selection plays little role in competition among species.

b. Two similar species in the same habitat that do not currently compete may have competed previously.

c. Niche overlap is always related to the degree of competition for a resource.

d. Character displacement is the convergence of characters to better exploit the same resource.

e. Resource partitioning is only a short-term solution, and all but one species will be outcompeted.

b. Two similar species in the same habitat that do not currently compete may have competed previously.

The following statements are examples of challenges a researcher might experience when studying competition under natural conditions relative to laboratory or greenhouse conditions. Which one of them is FALSE?

a. When conducting research under natural conditions, it is difficult to determine whether natural populations are at or below carrying capacity.

b. When conducting research under natural conditions, it is not always clear whether the effects of removing and adding individuals have anything to do with competition.

c. Researchers have little control over the environment when conducting research under natural conditions.

d. When conducting research under natural conditions, it is often not known what the life history requirements are of species in field conditions.

e. When conducting research under natural conditions, it is relatively easy to interpret experimental results.

e. When conducting research under natural conditions, it is relatively easy to interpret experimental results.

Which of the following statements supporting the argument that competition is extremely important in ecological systems is FALSE?

a. Coexisting species are always engaged in competitive interactions.

b. Competitor species show niche differentiation in space, time, and/or diet.

c. Competitive release has been documented in a number of areas.

d. Coexisting species that utilize the same resources within habitats may coexist by partitioning those resources.

e. Competitors show negatively associated distributions.

a. Coexisting species are always engaged in competitive interactions.

Which of the following provides evidence for the hypothesis that coyote range expansion is the result of competitive release?

a. In a series of field studies, researchers examined the relationships between gray wolves and coyotes in Yellowstone National Park using radio-collared wolves. Wolves preyed on elk and buffalo, while coyotes preyed on moose and mule deer.

b. In a series of field studies, researchers examined interference competition between gray wolves and coyotes in Yellowstone National Park using radio-collared wolves. Coyotes initiated the majority of encounters (85%), generally outnumbered wolves (39%), and dominated (91%) most interactions.

c. In a series of field studies, researchers examined interference competition between gray wolves and bears in Yellowstone National Park using radio-collared wolves. Wolves initiated the majority of encounters (85%), generally outnumbered bears (39%), and dominated (91%) most interactions.

d. In a series of field studies, researchers examined interference competition between gray wolves and coyotes in Yellowstone National Park using radio-collared wolves. Wolves initiated the majority of encounters (85%), generally outnumbered coyotes (39%), and dominated (91%) most interactions.

e. In a series of field studies, researchers examined the relationship between gray wolves and coyotes in Yellowstone National Park using radio-collared wolves. Wolves and coyotes often hunted together and facilitated each other’s kills.

d. In a series of field studies, researchers examined interference competition between gray wolves and coyotes in Yellowstone National Park using radio-collared wolves. Wolves initiated the majority of encounters (85%), generally outnumbered coyotes (39%), and dominated (91%) most interactions.

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. encounter competition.

b. preemptive competition.

c. consumption competition.

d. overgrowth competition.

b. preemptive competition.

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.

c. overgrowth competition.

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

a. overgrowth competition.

b. consumption competition.

c. preemptive competition.

d. encounter competition.

d. encounter competition.

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

a. True

b. False

b. False

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

a. True

b. False

b. False

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

a. consumption.

b. allelopathy.

c. toxicopathy.

d. competitive exclusion.

b. allelopathy.

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

a. Species A’s fundamental niche is restricted to a wet habitat.

b. Species A requires large amounts of moisture to grow.

c. Species B outcompetes A in the dry habitat.

d. Species B prefers a wet habitat.

c. Species B outcompetes A in the dry habitat.

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.

a. resource partitioning.

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

a. having the same competition coefficient.

b. niche differentiation.

c. zero-growth isoclines.

d. competitive exclusion.

b. niche differentiation.

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

a. competitive exclusion.

b. character displacement.

c. fundamental niche.

d. environmental gradient.

b. character displacement.

Competition typically

a. involves a predator and prey.

b. is random.

c. only involves two closely related species.

d. is a complex interaction of biotic and abiotic factors.

d. is a complex interaction of biotic and abiotic factors.

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

a. competition is impossible to measure in a natural setting.

b. scientists cannot control the environment.

c. it is difficult to know whether a population is at carrying capacity.

d. scientists lack full knowledge of the life history requirements of natural populations.

a. competition is impossible to measure in a natural setting.

In the following formula, what is β? dN2/dt = r2N2(1 – (N2 + N1)/K2)

a. growth rate

b. population size

c. competition coefficient

d. carrying capacity

c. competition coefficient

What is a zero-growth isocline?

a. when the population size of species 1 exceeds species 2

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

c. the set of values where α = β

d. the set of values where the carrying capacity is reached for one of the two species

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

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

a. Both species go extinct.

b. Both species coexist.

c. Species 1 wins.

d. Species 2 wins.

b. Both species coexist.

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

a. True

b. False

b. False

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

a. Both species coexist.

b. Species 1 drives species 2 to extinction.

c. The populations of both species increase to infinity.

d. Species 2 drives species 1 to extinction.

c. The populations of both species increase to infinity.

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

a. a competitive exclusion parameter.

b. a zero-growth isocline.

c. a competition coefficient.

d. the carrying capacity.

b. a zero-growth isocline.

What is the outcome of these isoclines?

a. Species 1 wins.

b. If species 2 begins with a higher abundance, it wins.

c. If species 1 begins with a higher abundance, it wins.

d. Species 2 wins.

a. Species 1 wins.

What is the outcome of these isoclines?

a. If species 1 begins with a higher abundance, it wins.

b. Both species coexist.

c. Species 2 wins.

d. Species 1 wins.

a. If species 1 begins with a higher abundance, it wins.

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

a. True

b. False

a. True

The Russian biologist G. F. Gause conducted a series of laboratory experiments on the Lotka-Volterra competition model. Gause found that Paramecium aurelia outcompetes Paramecium caudatum when they are grown together in a mixed culture. This is the classic example of __________.

a. a competitively unstable equilibrium

b. resource partitioning

c. competitively cyclic populations

d. competitive exclusion

e. competitive coexistence

d. competitive exclusion

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 but with the population of one species much higher than that of the other species.

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

c. can coexist but with the population of each species at half of the carrying capacity (K) as when each population is separate.

d. can coexist at the same carrying capacity (K) as when each population is separate.

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

The competitive exclusion principle assumes that the

a. competing species have different resource requirements.

b. superior competing species will have a lower population growth rate than the inferior competitor.

c. competing species have the same carrying capacity (K).

d. environmental conditions remain constant.

d. environmental conditions remain constant.

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

a. True

b. False

a. True

Which of the following is TRUE regarding competition?

a. Water temperature can influence the outcome of competitive interactions.

b. Competition is always focused on food.

c. The species larger in size typically outcompetes the smaller.

d. One species will always drive the other to extinction.

a. Water temperature can influence the outcome of competitive interactions.

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

a. temperature

b. water

c. light

d. nitrogen

a. temperature

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. growth rate differences among the species

c. Lotka-Volterra models predicting cycling

d. competitive exclusion principle

a. changes in precipitation across years

Typically species compete for

a. multiple resources simultaneously.

b. space.

c. food.

d. essential nutrients.

a. multiple resources simultaneously.

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.

a. True

b. False

a. True

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

a. competitive abilities change along environmental gradients.

b. of population cycling.

c. there are more predators at higher elevation.

d. older birds prefer lower elevations.

a. competitive abilities change along environmental gradients.

One effect of decreasing wolf populations in North America is

a. range expansion for coyotes.

b. increased bear populations.

c. decreased deer populations.

d. range retraction for elk.

a. range expansion for coyotes.

Coyote populations are lower where wolf populations are increasing because

a. wolves are a primary predator on coyotes.

b. wolves facilitate coyote populations by leaving scavenged meat.

c. wolves directly compete with coyotes.

d. wolves can withstand colder temperatures than coyotes.

c. wolves directly compete with coyotes.

in the absence of disturbance, an increase in the population growth of superior competitors results in low diversity. Disturbances so frequent that many populations fail to increase or experience extirpation also cause low diversity. It is at the INTERMEDIATE LEVEL OF DISTURBANCE that greatest diversity occurs.

predation, herbivory, fluctuation in the physical environment and all sorts of density independent mortality keep natural communities in a state of disturbance or non-equilibrium

most communities fail to achieve equilibrium because of a fluctuating environment and periodic reductions in populations

in the absence of disturbance, in an increase in the population growth of superior competitors results in low diversity

disturbances so frequent that many populations fail to increase or experience extirpation also cause low diversity. It is at the intermediate level of disturbance that greatest diversity occurs

intermediate Disturbance Hypothesis

when disturbances are rare the system goes to competitive equilibrium and competitive exclusion occurs when disturbances are frequent only opportunistic species can survive the brief favorable periods at intermediate levels of disturbance both opportunistic species and competitively superior species can occur

keystone predator

species of high tropic status that through its predation exerts a disproportionately great influence on the species composition or diversity of community

dominate species

most important species in terms of number of biomass at a particular trophic level

dN/dt = r1N1=((K1-N1-alphN2)/K1)

competitive exclusion principle

a fundamental principle of ecology states that 2 species identical in ecological requirements cannot LONG coexist or complete competitors cannot long coexist

How might organisms with similar niches coexist in nature?

1) Competition is rare because populations(and guilds) are kept below k – non-equilibrium model 2) Competition through evolution history has resulted in adaptations that minimize competitive effects ( the ghost of competition past)- equilibrium model 3) fluctuating environment lead to reversals of competitive ability before exclusion occurs – equilibrium model

when arrows on sides face away = unstable
when arrows face toward equilibrium point = stable

metapopulations dynamics

meta population dynamics involve a balance between extinction and re-colonization extinction and subsequent recolonization of a habitat patch callredan extinct-colonization TURNOVER EVENT length until extinction called meta-population persistence time

CHOAS

r>2.57 = chaos chaos = an extremely irregular population trajectory with no characteristic period a trajectory that no longer repeats itself = something of ifnite period can be predicted = deterministic trajectories that are infinitely close together diverge exponentially -extreme sensitivity to initial conditions deterministic chaos = chaotic trajectories can be predicted, just not far into the future because of extreme sensitivity to initial conditions

When discrete logistic equation:
R<1, results in a unaltered sigmoid curve for population growth, smooth approach to carrying capacity
1<R>2, R between 1 and 2 results in dampened osculations eventually remaining stable at carrying capacity
2<R>2.57, results in stable limit cycle around carrying capacity, ranging from oscillation between two values at 2.01 up tp a limit cycle with 32 values at an R of about 2.569
R>2.57=Choas

Share This
Flashcard

More flashcards like this

NCLEX 10000 Integumentary Disorders

When assessing a client with partial-thickness burns over 60% of the body, which finding should the nurse report immediately? a) ...

Read more

NCLEX 300-NEURO

A client with amyotrophic lateral sclerosis (ALS) tells the nurse, "Sometimes I feel so frustrated. I can’t do anything without ...

Read more

NASM Flashcards

Which of the following is the process of getting oxygen from the environment to the tissues of the body? Diffusion ...

Read more

We can Write a Custom Essay

Consectetur labore ullamco magna do irure fugiat Lorem

Check Price

Successful message
sending