Deck 4: Populations and Communities

Question 1

In logistic growth (an S-shaped curve),how does population growth change as the population nears its carrying capacity?

A)Population growth increases.
B)Population growth remains steady.
C)Population growth decreases.
D)Population growth typically crashes when a population nears its carrying capacity.

Answer 1

Population growth decreases.

Question 2

Some beetles escape from a ship and fly to a small island covered with grass but with no trees or beetle predators.As the beetles feed,they destroy all the grasses.But with abundant food,the beetle population soars,doubling in size every month.After about a year,the population crashes as thousands of beetles have destroyed almost all of the plants and there is little left to feed the large population.This scenario best illustrates

A)constant growth followed by equilibrium.
B)a population that has stabilized near its carrying capacity.
C)exponential growth followed by a population crash.
D)the fact that the beetles have strong competition from other species for food supply.

Answer 2

exponential growth followed by a population crash.

Question 3

A squirrel population in an oak forest in Indiana is limited by hawk predators,the amount of acorns produced annually,nesting sites in the trees,and cold winter temperatures.
Which of the following is an abiotic factor limiting this squirrel population?

A)the hawks in the region
B)the number of acorns produced annually
C)the stress of cold winter temperatures
D)the number of available nesting sites

Answer 3

the stress of cold winter temperatures

Question 4

A stable population would remain at equilibrium if

A)the birth rate increased as the death rate decreased.
B)emigration rates and death rates increased equally.
C)births and immigration increased by the same number of organisms.
D)births and deaths increased by the same number of organisms.

Question 5

The population of game fish in a lake is under heavy fishing pressure.If too many fish are caught,the population will crash and future years of fishing will suffer.The game fish can exhibit logistic growth under certain circumstances.Assuming logistic growth,it would be best to manage this game fish population by permitting the harvesting of just enough fish to keep the game fish population

A)at 1/10 of its carrying capacity.
B)at half its carrying capacity.
C)at its full carrying capacity.
D)above its carrying capacity.

Question 6

Which one of the following is characteristic of a K-selected species?

A)fast reproductive rate
B)large body size
C)short life span
D)production of large numbers of offspring

Question 7

Which of the following organisms is most likely a K-strategist?

A)oak trees
B)bacteria
C)puffball mushrooms
D)fruit flies

Question 8

A group of frogs in a rain forest represents a population if the frogs

A)live in the same region and can potentially reproduce with each other.
B)look similar to each other and seem to be well adapted to the same region.
C)are preyed upon by the same group of predators and seem to be camouflaged.
D)live in the same region and feed on about the same types of food.

Question 9

Golden frog populations would be more likely to survive the current threats if

A)their populations were more widely distributed across Central and South America.
B)their populations were smaller in size.
C)individuals were genetically more similar to each other.
D)they only fed on a single type of food.

Question 10

Sustainable populations

A)are often near their carrying capacity.
B)have exceeded their biotic potential.
C)have grown beyond all types of environmental resistance.
D)are characterized by high emigration and low recruitment.

Question 11

A population that is at equilibrium

A)is experiencing a slow rate of growth.
B)is staying at about the same size.
C)is slowly declining because of increases in environmental resistance.
D)has most likely just lost a key predator.

Question 12

In North America,a toxic weed called leafy spurge was accidentally introduced and has grown and spread rapidly,covering millions of acres in north central United States and south central Canada.Leafy spurge is generally avoided by cattle and horses and may be toxic to them.Thus,rangeland where leafy spurge has spread has been damaged by the invasion of this plant.
Plants such as leafy spurge can double their population size every year in part because of their efficient production of large amounts of seeds.Populations that can double every year,such as leafy spurge,

A)will do so endlessly,eventually achieving a global distribution.
B)are examples of logistic growth.
C)probably have more predators than other species.
D)exhibit exponential growth as they spread to new regions.

Question 13

In North America,a toxic weed called leafy spurge was accidentally introduced and has grown and spread rapidly,covering millions of acres in north central United States and south central Canada.Leafy spurge is generally avoided by cattle and horses and may be toxic to them.Thus,rangeland where leafy spurge has spread has been damaged by the invasion of this plant.
Leafy spurge has spread completely across many US states.If left uncontrolled in these states,leafy spurge populations will

A)never experience environmental resistance.
B)eventually reach their carrying capacity.
C)shift from a J-curve to a constant rate of growth.
D)shift from a logistic curve to a J-shaped growth curve.

Question 14

A population would be expected to grow if

A)immigration increased and deaths and emigration decreased.
B)immigration and emigration increased by the same number of organisms.
C)emigration and death rates stayed the same and immigration decreased.
D)births decreased by 1% and emigration increased by 8%.

Question 15

A squirrel population in an oak forest in Indiana is limited by hawk predators,the amount of acorns produced annually,nesting sites in the trees,and cold winter temperatures.
A population of bullfrogs in a pond produces many thousands of eggs each spring that hatch out into tadpoles.However,only about 1% of the tadpoles survive to reproduce.This population of frogs is experiencing

A)low environmental resistance.
B)low levels of recruitment.
C)unlimited population growth.
D)exponential growth.

Question 16

Flea beetles alone are unlikely to eliminate all of the leafy spurge in a region.Instead,the number of leafy spurge plants and the number of flea beetles in a particular community may stabilize.At this point,the leafy spurge and flea beetle populations

A)have exhibited exponential growth followed by a crash.
B)have experienced constant growth.
C)are still experiencing exponential growth.
D)are experiencing environmental resistance.

Question 17

Along the shoreline of a pond,Canadian geese,American toads,and grass frogs search for food while bluegill and bass prey on small fish in the shallow water.These species,living and feeding in this particular location,represent one

A)species.
B)population.
C)community.
D)ecosystem.

Question 18

A squirrel population in an oak forest in Indiana is limited by hawk predators,the amount of acorns produced annually,nesting sites in the trees,and cold winter temperatures.
The many factors listed above that can affect the squirrel population represent

A)environmental resistance.
B)the carrying capacity of the squirrel population.
C)the squirrel's life history.
D)the biotic potential of the squirrel population.

Question 19

It is common to hear about the huge reproductive potential of some organisms.Perhaps someone has mentioned that if all of the eggs of houseflies were to survive to maturity,the world would soon be covered in flies.This does not happen because,in reality,

A)the biotic potential would be limited by environmental resistance.
B)the biotic potential would continue to increase.
C)environmental resistance would increase,increasing the carrying capacity.
D)house flies would find it too difficult to locate a potential mate.

Question 20

Many strategies have been used to control leafy spurge,including the deliberate introduction of different species of flea beetles that feed on leafy spurge.Each flea beetle female may lay about 200 eggs in her only year of life.In places where flea beetle introductions have quickly established large populations that have grown and stabilized,the population growth of these beetles most likely looked like

A)a straight increasing line.
B)a J-shaped curve.
C)an S-shaped curve.
D)an upside down U-curve.

Question 21

Which one of the following illustrates interspecific competition?

A)The largest wolves in a pack are the first to feed on a freshly killed deer.
B)Two honeybees from the same colony converge on a flower to collect pollen and nectar.
C)Advertising its nectar with red colors,a columbine flower attracts a hummingbird for a meal.
D)Caterpillars of two different species of moth are feeding on the same plant's leaves.

Question 22

In general,it is rare for a parasite to

A)feed on a host.
B)kill its host.
C)spread from one host to another.
D)compete with other parasites for access to a host.

Question 23

Which of the following represents a type of top-down regulation for wildflowers living in a forest?

A)types of minerals in the soil
B)amount and timing of precipitation
C)strength and frequency of sunlight
D)herbivores in the region

Question 24

Dung beetles live in regions where cattle graze,quickly burying and recycling cattle droppings.Because of the dung beetle's activities,breeding habitats and resources for disease-carrying flies are reduced and the plants upon which cattle feed are nourished.
The relationship between the dung beetles and the disease-carrying flies is a type of

A)mutualism.
B)commensalism.
C)intraspecific competition.
D)interspecific competition.

Question 25

A grasshopper population in a prairie is limited in large part by the number of birds in the region.Following a terrible storm that killed many of the birds,the grasshopper population exhibits exponential growth.This happens because the grasshoppers experienced

A)a new biotic potential with steady environmental resistance.
B)a new much lower biotic potential with decreased environmental resistance.
C)a steady biotic potential but suddenly decreased environmental resistance.
D)a decreased biotic potential and decreased environmental resistance.

Question 26

Many predator-prey relationships do not result in the complete elimination of the prey because

A)predators cannot catch all of the healthy adults.
B)the predator population is limited by the availability of territorial space.
C)the prey do not provide enough nutrition.
D)the prey populations are always far below carrying capacity.

Question 27

In a mature forest in a national park,maple trees grow very large and live more than 80 years.Over an average lifetime,a tree produces more than 100,000 seeds,of which only 2-3 sprout and grow to maturity.This maple tree is

A)K-selected and exhibits a type I survivorship curve.
B)K-selected and exhibits a type III survivorship curve.
C)r-selected and exhibits a type I survivorship curve.
D)r-selected and exhibits a type III survivorship curve.

Question 28

Parasites

A)affect their hosts in a density-independent manner.
B)and their hosts represent a type of intraspecific competition.
C)occur in animals but not plants.
D)may live inside or outside of their host.

Question 29

The most stable predator-prey relationships typically involve

A)a prey species and several natural predators.
B)two species of carnivores eating each other.
C)only bottom-up population regulation.
D)only top-down population regulation.

Question 30

Sumatran rhino populations have declined steadily to a point near extinction.Because of its population decline,this unusual forest-dwelling rhino is near its

A)carrying capacity and is officially listed as threatened.
B)carrying capacity and is officially listed as endangered.
C)critical number and is officially listed as threatened.
D)critical number and is officially listed as endangered.

Question 31

A population of catfish in a muddy pond reaches its maximum size as the food supplies start to run low.Without any new sources of food,the catfish population remains steady.This population represents

A)density-dependent logistic growth.
B)density-independent logistic growth.
C)density-dependent exponential growth.
D)density-independent exponential growth.

Question 32

In general,K-strategists have a

A)type I survivorship pattern,and r-strategists have a type III survivorship pattern.
B)type II survivorship pattern,and r-strategists have a type I survivorship pattern.
C)type II survivorship pattern,and r-strategists have a type III survivorship pattern.
D)type III survivorship pattern,and r-strategists have a type II survivorship pattern.

Question 33

Density-independent factors such as earthquakes and hurricanes are

A)abiotic factors that maintain a population near equilibrium.
B)biotic factors that maintain a population near equilibrium.
C)abiotic factors that are not involved in maintaining a population near its equilibrium.
D)biotic factors that are not involved in maintaining a population near its equilibrium.

Question 34

Which of the following represents a type of mutualism?

A)A red-tailed hawk pounces on a field mouse for dinner.
B)A large herd of zebra graze lazily across the broad savannah.
C)A mosquito draws a blood meal from the back of an elk.
D)A honeybee feeds on nectar at a flower on an orange tree and pollinates the flower.

Question 35

Walking through a national park,you step off a well-marked trail to take a photograph and accidentally trample a rare orchid.This is an example of

A)commensalism.
B)mutualism.
C)predation.
D)amensalism.

Question 36

The relationship between the moose and wolf populations on Isle Royale reveals

A)intraspecific competition.
B)top-down and bottom-up population regulation.
C)the high and steady environmental resistance on wolves.
D)the high and steady environmental resistance on moose.

Question 37

Which of the following represents a type of top-down regulation for rattlesnakes living in Arizona?

A)the availability of fresh water
B)the number of mice in the region
C)abundance of rocks under which snakes can hide
D)the number of snake-eating hawks in the region

Question 38

Dung beetles live in regions where cattle graze,quickly burying and recycling cattle droppings.Because of the dung beetle's activities,breeding habitats and resources for disease-carrying flies are reduced and the plants upon which cattle feed are nourished.
The relationship between the dung beetles and the cattle is a type of

A)mutualism.
B)parasitism.
C)intraspecific competition.
D)interspecific competition.

Question 39

Which of the following is analogous to a mutualistic relationship?

A)A basketball player is paid by a company to wear its particular brand of shoes.
B)A deer hunter stalks and kills a large buck.
C)A thief breaks into a store and steals some precious jewels.
D)Young lovers leave their initials carved onto a tree,which then gets diseased and dies.

Question 40

Threatened and endangered species receive special protection from human activities such as hunting and habitat destruction because these activities may continue despite the species' low numbers.These human activities therefore

A)are density independent.
B)are density dependent.
C)represent bottom-up regulation.
D)represent harmful abiotic resistance.

Question 41

A keystone species

A)has a disproportionately large impact on the stability of an ecosystem.
B)typically reduces overall biodiversity of an ecosystem.
C)is typically an herbivore.
D)is an example of amensalism.

Question 42

The relationships among elk predators represent

A)the impacts of overgrazing.
B)a set of keystone species.
C)interspecific competition.
D)biotic potential.

Question 43

The reindeer population changes on St.Matthew Island appears to have ultimately been caused by

A)the absence of any predators.
B)the addition of a keystone species.
C)the narrow reliance of reindeer on just a single food species.
D)the introduction of grizzly bears to the island in 1962.

Question 44

The concept of biological fitness is based on two separate abilities.These are the ability to

A)survive and reproduce.
B)find a mate and have offspring.
C)defend against enemies and find food.
D)produce and defend a family.

Question 45

The separate feeding locations of these five warbler species on different portions of the same tree illustrates

A)biotic transformation.
B)competitive exclusion.
C)resource partitioning.
D)top-down population regulation.

Question 46

Brown-headed Cowbirds lay their eggs in other birds' nests,relying upon another species to raise their chicks.Although many species continue to raise the cowbird chicks,some species reject the eggs and offspring.Further,Brown-headed Cowbirds are rare inside large forests.Which of the following represents an adaptation in response to this cowbird threat?

A)breeding birds of other species raising cowbird chicks
B)breeding birds of other species nesting in deep forests
C)breeding birds of other species attracting cowbird adults to their region
D)breeding birds of other species changing to a different type of bird song

Question 47

Which one of the following illustrates intraspecific competition?

A)a butterfly feeding on the nectar of a daffodil flower
B)a sea gull swooping down to snatch a fish from the water's surface
C)a tick and a flea sharing a dog's back
D)male red-winged blackbirds defending nesting sites from other males

Question 48

Resource partitioning

A)reduces interspecific competition and increases species diversity.
B)reduces intraspecific competition and decreases species diversity.
C)increases interspecific competition and decreases species diversity.
D)increases intraspecific competition and increases species diversity.

Question 49

In an ecosystem,the elimination of one new species by another because of direct competition for the same resources is an example of

A)intraspecific competition.
B)the competitive exclusion principle.
C)character displacement.
D)resource partitioning.

Question 50

Territoriality

A)reduces intraspecific fighting and ensures adequate resources for some members of a species.
B)encourages interspecific fighting and helps share density-independent resources.
C)encourages predation and reduces intraspecific competition.
D)is more likely in r-selected species with short life spans and many offspring.

Question 51

In its broadest sense,fitness reflects the ability to respond to

A)other members of the same species.
B)abiotic environmental factors.
C)all factors of environmental resistance.
D)parasites and other agents of disease.

Question 52

These photos all illustrate examples of

A)parasitism.
B)commensalism.
C)amensalism.
D)mutualism.

Question 53

In an ecosystem with many similar species,we typically find

A)intense interspecific competition mostly for food.
B)competitors using different resources to minimize interspecific competition.
C)intense interspecific competition mostly for nesting sites.
D)adaptations for battles and interspecific competition.

Question 54

This photo best illustrates

A)amensalism.
B)parasitism.
C)commensalism.
D)mutualism.

Question 55

Some biologists have identified symbiotic relationships in which it appears that one organism gains from the relationship while the other organism is unaffected.Although after further research,the researchers find out that both members of the relationship actually benefit.The researchers therefore realize that what they at first thought was an example of

A)mutualism is really an example of commensalism.
B)commensalism is really an example of mutualism.
C)symbiosis is really an example of parasitism.
D)symbiosis is really an example of amensalism.

Question 56

Over the last 100 years,the number of elk in Yellowstone has varied in part because of the limited availability of winter food sources and many types of predators,including wolves (eliminated in 1926 and reintroduced in 1995),grizzly bears,coyotes,black bears,and golden eagles.
The population of elk in Yellowstone

A)reflects top-down and bottom-up population regulation.
B)has survived because of the elimination of a keystone species.
C)would have been more stable if there had only been one predator species.
D)would be better off if all predators were eliminated from the park.

Question 57

A prairie grass may experience grazing herbivores,wildfires,droughts,deep snow,or blazing hot days in the summer.Yet,those prairie grasses alive today are descendants of those that have survived these challenges and more.From an evolutionary perspective,these sorts of environmental challenges are identified as

A)herbivory.
B)predation.
C)selective pressures.
D)biological adaptations.

Question 58

Two species have separate ranges but use the same food resources.However,their ranges overlap in one area.It is found in the area of overlap the species have evolved separate anatomical specializations that reduce interspecific competition for food.This is an example of

A)biotic transformation.
B)competitive exclusion.
C)resource partitioning.
D)character displacement.

Question 59

Darwin and Wallace discovered natural selection without knowledge of an important field of biology that is very much a part of biological evolution.What essential part of biological evolution was poorly understood when they first presented natural selection to the world?

A)geology
B)genetics
C)anatomy
D)physiology

Question 60

Competitive exclusion is not as common as many biologists expected,in large part because

A)there just are not that many species of organisms on Earth.
B)ecosystems are more homogeneous than was appreciated.
C)even when two species share an identical niche,they find a way to cooperate.
D)heterogeneous environments allow apparent competitors to occupy separate niches.

Question 61

Genetic diversity in a species does not arise from

A)mutations.
B)meiosis.
C)crossover.
D)need or want.

Question 62

The Ivory-Billed Woodpecker may have been found in deep woods of Missouri.Even though a few individuals may have survived,this may not be enough to avoid extinction of this species.What else must these few birds do to ensure the survival of the species?

A)defend a territory against other bird species and predators
B)maintain a viable breeding colony
C)shift to a new source of food widely available in their region
D)migrate to a better habitat that is more protected from people

Question 63

New genetic traits upon which natural selection can act usually arise from

A)mutations and crossover.
B)increases in cell size and shape.
C)the need to become adapted to a new environment.
D)the demands of the environment.

Question 64

If organisms are unable to generate enough genetic diversity to survive in a changing environment,they

A)may produce more offspring.
B)sometimes go extinct.
C)may evolve by non-genetic mechanisms.
D)will start to reproduce asexually.

Question 65

The different Galápagos finch species

A)evolved in South America and flew to the Galápagos Islands.
B)evolved from a single ancestral species that flew to the Galápagos Islands.
C)all feed on the same diet in the Galápagos Islands.
D)are primarily different because of variations in the structure of their feet.

Question 66

If the climate of an environment is rapidly changing,which one of the following organisms would most likely go extinct?

A)a bacterial species that exchanges genetic material with other bacteria
B)a species of fish that only reproduces asexually
C)a large interbreeding population of snails
D)a plant species that can reproduce both asexually and sexually

Question 67

The unusual organisms living in Australia have evolved primarily because of

A)the unique position of Australia on the face of Earth.
B)shifting ocean currents around the continent.
C)long term isolation of the continent.
D)the unusual climates of Australia.

Question 68

Adaptation takes place in response to

A)anticipated needs.
B)selective pressures they have not yet experienced.
C)only the selective pressures they experience.
D)only selective pressures that favor survival.

Question 69

In short,different selective pressures in closely related species will produce

A)similar migration patterns.
B)similar reproductive strategies.
C)different adaptations.
D)new mutations.

Question 70

The evolution of a new species is most like

A)designing a new home and building it.
B)remodeling an old home into a new one.
C)using parts of many junked cars to construct a new one.
D)creating a virtual car on a computer.

Question 71

Without human intervention to save a species from extinction,which one of the following organisms would be most likely to survive threats to its extinction?

A)a flower species that produces three seeds a year and lives for up to 4 years
B)a mushroom species that releases millions of airborne spores and dies
C)an elephant species that provides parental care for 1 or 2 offspring for more than a year
D)a frog that lays 50-100 eggs every year for 2-3 years

Question 72

Introduced species are a growing problem primarily because of

A)global trade and travel.
B)plate tectonics.
C)the speed at which new species form.
D)global climate change.

Question 73

Kudzu vine,chestnut blight,fire ants,and Japanese beetles are all examples of

A)asexually reproducing species.
B)invasive species.
C)species that evolved because of recent geographic isolation.
D)species that evolved on the Galápagos Islands.

Question 74

Groups of organisms that may have been separated for millions of years may be brought together in new combinations primarily by

A)shifting weather patterns.
B)changes in ocean currents.
C)plate tectonics.
D)changes in the Earth's magnetic fields.

Question 75

When a single species evolves into two species,the new species must

A)be reproductively isolated.
B)evolve different diets.
C)be exposed to the same selective pressures.
D)live on a different continent.

Question 76

Which one of the following is the best analogy to the movements of continents by plate tectonics?

A)a worm tunneling through soil
B)noodles drifting throughout a cup of chicken noodle soup
C)air mattresses drifting about on the top of a swimming pool
D)a train running along its tracks

Question 77

On Earth today,mountains such as the Himalayas are rising because of

A)extensive erosion caused by increases in rainfall in those regions.
B)subterranean pockets of natural gas forcing their way to the surface.
C)low density rocks that are being forced upward through high density rocks.
D)collisions between tectonic plates.

Question 78

Newly formed species typically have experienced different

A)numbers of offspring.
B)life spans.
C)dietary habits.
D)selective pressures.

Question 79

Which one of the following is a trait that increases the chances of survival for an endangered species?

A)large size
B)a food source consisting of a single species
C)widespread distribution
D)small number of offspring

Question 80

The fluid core of the Earth

A)is mostly water that has leaked in from the oceans.
B)remains fluid because of heat generated by radioactive decay.
C)results from heat generated by the friction of the tectonic plates moving over each other.
D)is a watery substance that lubricates the movement of the tectonic plates.