Deck 34: Population Ecology

Question 1

List the features used to identify a species as an opportunistic species (r-strategist).

Answer 1

small individuals short life span fast to mature many offspring little or no parental care of offspring many offspring die before reaching reproductive age early reproductive age

Question 2

The study of the interrelationships of plants and animals with each other and with their environment is known as

A)a trophic level.
B)a food web.
C)a habitat.
D)a biosphere.
E)ecology.

Answer 2

E

Question 3

Which of the following is NOT a form of environmental resistance?

A)limited food supply
B)accumulation of waste products
C)number of offspring produced per litter
D)predation
E)limited living space

Answer 3

C

Question 4

Explain the species interactions in each of the following symbiotic relationships: parasitism,commensalism,and mutualism.

Question 5

Ecology is best defined as the study of

A)populations.
B)the rate of population changes.
C)communities.
D)how populations are restricted by environmental resistance.
E)organisms as they interact with other organisms and with their physical surroundings.

Question 6

Consider that a species of salmon lays 20,000 eggs per pair when it spawns and dies.At the end of five years,an average of one pair of mature salmon from this group of hatched eggs returns again to spawn in the parent stream (19,998 have died).What is the per capita rate of increase?

A)10,000,because there were that many eggs produced per parent fish (r)
B)2,000,because this must be divided by five years
C)zero,because there is exact replacement of the previous generation
D)-2,000,because there was this much average die-off per year
E)-19,998,because there was this much total loss

Question 7

All the members of the same species that inhabit a particular area are termed a(n)

A)ecosystem.
B)biosphere.
C)ecological niche.
D)population.
E)community.

Question 8

Which of the following does not impact an organism's biotic potential?

A)number of offspring per reproduction
B)chances of survival until age of reproduction
C)age at which reproduction begins
D)how often each individual reproduces
E)the rate of immigration into an area

Question 9

Population growth rate would be negative when

A)birthrate is greater than death rate.
B)death rate is greater than birthrate.
C)all couples are married but average less than two children apiece.
D)a country becomes poorer,because it is related to economic growth.
E)better health care reduces the death rate and increases survivorship of newborns.

Question 10

The relatively thin layer on the earth's surface where life is possible is known as the

A)ecosystem.
B)biosphere.
C)biome.
D)biopreserve.
E)lithosphere.

Question 11

The maximum per capita rate of increase for a population that can occur under ideal conditions is the

A)population growth.
B)biotic potential.
C)environmental resistance.
D)carrying capacity.
E)doubling time.

Question 12

An ecosystem contains

A)only the biotic (living)components of the environment.
B)only the abiotic (nonliving)components of the environment.
C)only the energy flow components of an environment.
D)both the living organisms and the abiotic components of the environment.
E)only the food relationships found in an environment.

Question 13

Which of the following would allow optimal population growth?

A)accumulation of waste products
B)predation
C)competition
D)limited access to food and water
E)unlimited resources

Question 14

Biotic potential depends on all of the following EXCEPT

A)the number of offspring per reproduction.
B)how often each individual reproduces.
C)how many different mates each individual has.
D)chances of survival until the age of reproduction.
E)the age at which reproduction begins.

Question 15

A number of populations of different species interacting with one another in a natural environment,such as a rotten log,is called

A)competition.
B)a community.
C)a biome.
D)predation.
E)symbiosis.

Question 16

All of the organisms living in your front yard represent a(n)_______,while the blue jays represent a(n)______.

A)population; community
B)population; ecosystem
C)ecosystem; population
D)community; population
E)ecosystem; community

Question 17

Explain the correct sequence of events in secondary succession of a forest.

Question 18

When the number of births exceeds the number of deaths,this results in

A)population growth.
B)biotic potential.
C)environmental resistance.
D)carrying capacity.
E)doubling time.

Question 19

A number of populations of different species interacting with one another is called

A)competition.
B)a community.
C)an ecosystem.
D)predation.
E)symbiosis.

Question 20

A scientist observes a population of grasshoppers in a farmer's field several times over the summer.She notices that after each application of an insecticide the grasshopper population increases to its pre-pesticide levels very rapidly and that the population never goes near zero at any time.The scientist's results indicate the grasshopper population is probably

A)in the lag phase.
B)in the exponential growth phase.
C)in the deceleration phase.
D)in the stable equilibrium phase.
E)at carrying capacity.

Question 21

Age structure diagrams with a broad base suggest that

A)the population will continue to grow for some time.
B)environmental resistance is not at work.
C)the biotic potential must be larger than usual.
D)the individuals must be larger than usual.
E)there are many older individuals in a population.

Question 22

Population size is believed to level off at the _______ of an environment.

A)population growth
B)biotic potential
C)environmental resistance
D)carrying capacity
E)doubling time

Question 23

Which of the following describes a type II survivorship curve (drawn by plotting the number of individuals in a given population alive at the beginning of each age interval)?

A)Most individuals die of old age.
B)Many individuals die early in life.
C)Individuals die at a constant rate throughout time.
D)Most individuals die during their reproductive years.
E)Most individuals die before old age,but after their reproductive years.

Question 24

Which of the following is a true statement?

A)The growth rate can be positive and a population can still be the same size year after year.
B)The growth rate has to be zero before a population can be the same size year after year.
C)Replacement reproduction automatically gives a growth rate of zero.
D)A growth rate of zero means the population is dying.
E)The growth rate can be negative and a population can still be the same size year after year.

Question 25

The human growth curve is best described as being

A)flat.
B)J-shaped.
C)V-shaped.
D)S-shaped.
E)W-shaped.

Question 26

If the growth rate of a population increases,the doubling time

A)increases.
B)decreases.
C)remains the same.
D)depends on the amount of natural resources.
E)is not related to growth rate increase.

Question 27

Which of the following is NOT true?

A)Many MDCs have a stabilized age structure diagram.
B)Most LDCs have a youthful age structure diagram.
C)The quicker the replacement reproduction is achieved,the sooner the zero population growth results.
D)The human population growth curve is exponential.
E)As the human population increases in size,less energy but more material will be consumed.

Question 28

The demographic transition,where population growth slows in developed countries,may be attributed at least in part to

A)socialization.
B)sensitivity.
C)an increase in family size.
D)the rise of medicine.
E)education.

Question 29

When growth proceeds at a rate similar to 2 $\rightarrow$ 4 $\rightarrow$ 8 $\rightarrow$ 16 $\rightarrow$ 32 $\rightarrow$ 64...etc.,it is called

A)arithmetic growth.
B)additive growth.
C)exponential growth.
D)zero population growth.
E)carrying capacity.

Question 30

Which of the following describes a type I survivorship curve (drawn by plotting the number of individuals in a given population alive at the beginning of each age interval)?

A)Most individuals die of old age.
B)Many individuals die early in life.
C)Individuals die at a constant rate throughout time.
D)Most individuals die during their reproductive years.
E)Most individuals die before old age,but after their reproductive years.

Question 31

The demographic transition,where population growth slows in developed countries,is due to a(n)

A)decreased death rate followed by a decreased birthrate.
B)decreased death rate followed by increased birthrate.
C)increased death rate followed by a decreased birthrate.
D)increased death rate followed by increased birthrate.
E)loss of a large number of members of the child-bearing age population.

Question 32

The maximum population that the environment can support for an indefinite period of time is called the

A)biotic potential.
B)environmental resistance.
C)carrying capacity.
D)replacement reproduction.
E)demographic transition.

Question 33

Which of the following statements accurately describes the less developed countries?

A)high birthrate,large pre-reproductive portion of the population
B)high birthrate,different age groups of equal size
C)high growth rate,reproductive portion of the population is the largest
D)low growth rate,different age groups of equal size
E)high growth rate,different age groups of equal size

Question 34

If a population has many more young women entering the reproductive years than older women leaving the reproductive years,which of the following statements is NOT true?

A)The growth rate will most likely increase.
B)The replacement reproduction will give a positive growth rate.
C)It is likely to be a MDC.
D)It is likely to be a LDC.
E)The population will continue to grow as more young women enter the reproductive phase.

Question 35

Consider the life of the praying mantis.The large predatory female lays several hundred eggs in a foam mass in the fall.The young are most vulnerable when they emerge in the spring,but the few that survive spread out over the countryside and,if they find a mate,lay eggs the following fall.Which type of survivorship curve does this represent?

A)type I
B)type II
C)type III
D)exponential growth followed by a decline from resource depletion
E)maximal exponential growth and minimal use of carrying capacity

Question 36

A population with rapidly expanding exponential growth would be best represented by a graph with a(n)______-shaped curve.

A)bell
B)urn
C)pyramid
D)S
E)J

Question 37

The carrying capacity of the environment for a species is determined by

A)the reproductive rate of the organism.
B)the number of organisms of that species.
C)the state and national wildlife laws pertaining to that species.
D)a complex "balance of nature" that still has not been explained in terms that scientists can calculate.
E)the limited productivity of the environment and the environmental resistance to the biotic potential of the organism.

Question 38

Replacement reproduction occurs when

A)the number of births equals the number of deaths.
B)each couple has an average of two children,which also results in zero population growth.
C)each couple has an average of two children,but population growth may still occur.
D)the population reaches carrying capacity.
E)all of the adult population is married.

Question 39

Which of these is most likely true?

A)The less developed countries will always have a high growth rate with no accompanying problems.
B)The growth rate will decline only when the less developed countries are industrialized as much as the more developed countries.
C)A good family planning program can help the growth rate decline even if the country is not yet industrialized.
D)The less developed countries already have a low growth rate.
E)The growth rate of more developed countries contributes more to world population growth.

Question 40

Which of the following describes a type III survivorship curve (drawn by plotting the number of individuals in a given population alive at the beginning of each age interval)?

A)Most individuals die of old age.
B)Many individuals die early in life.
C)Individuals die at a constant rate throughout time.
D)Most individuals die during their reproductive years.
E)Most individuals die before old age,but after their reproductive years.

Question 41

A population age structure diagram in which the birthrate is high and the population is mainly young would be best represented by a graph with a(n)

A)bell shape.
B)urn shape.
C)pyramid shape.
D)S-shaped curve.
E)J-shaped curve.

Question 42

In nature,animals tend to be either an opportunistic or equilibrium species or somewhere along an intermediate point between the two.Why aren't there animals in nature that are both big,fierce,and highly reproductive so they leave many offspring?

A)Most animals are both opportunistic and equilibrium species.
B)There is no limitation; such an animal could evolve.
C)It is structurally impossible for a large animal to have many young.
D)You can "spend" your energy to be a large equilibrium species,to produce many offspring as an opportunistic species,or to be somewhere in between,but you can't spend the energy to be both large and highly reproductive.
E)Large animals are incapable of producing large numbers of offspring.

Question 43

Overall,the most scientifically correct viewpoint toward predators is

A)predators help keep prey populations from overexploiting limited food resources.
B)generally,ecosystems support more and healthier populations when the large carnivores are eliminated from the system.
C)there is a high level of cruelty and indiscriminate killing among larger predators.
D)when we eliminate predators that could harm us and our activities,we also improve conditions for other animal populations.
E)predators are a neutral influence on prey populations and our activities merely substitute us for the prey we eliminate.

Question 44

Which of the following is correct when describing a predator-prey cycle?

A)A decline in the number of predators causes a decline in the number of prey.
B)A decline in the number of prey causes a decline in the number of predators.
C)An increase in the number of predators triggers an increase in the number of prey.
D)An up-and-down cycle will be seen for the prey animal.
E)A seasonal die-off will occur without the other species present.

Question 45

The outbreak of a disease,such as the bubonic plague,that kills large numbers of people in a city is an example of

A)a density-independent factor.
B)a density-dependent factor.
C)a commensalistic factor.
D)a symbiotic relationship.
E)predation.

Question 46

Which is NOT a density-dependent factor?

A)food supply
B)weather
C)shelter or nest space
D)disease
E)predators

Question 47

Which of the following is NOT an anti-predator defense mechanism?

A)Plant chemicals,including coffee and tea caffeine,make caterpillars sick or jittery.
B)The large eyespots on a moth's wing are exposed abruptly to startle a hungry bird.
C)Many trees,vines,and shrubs have stems lines with long thorns.
D)Prairie dog towns always have several prairie "watchdogs" to alert them of approaching hawks and snakes.
E)Many plants have brightly colored fruit and flowers.

Question 48

Similar species occupying slightly different niches in the same community is shown by

A)the presence of carp in polluted waters in the United States.
B)fluctuation of the snowshoe hare and lynx populations in Canada.
C)competition between two species of barnacles in Scotland,resulting in one living in the intertidal zone and the other living below this species.
D)removal of a starfish species from intertidal communities in Washington.
E)killing dingoes in Australia or coyotes in the American West.

Question 49

There are two organisms with overlapping ranges and filling a similar niche.We find that where their niches overlap,there is twice the competition for resources.This leads to

A)speciation.
B)hypervolume.
C)competitive exclusion.
D)total extinction of one species.
E)a switch in habitat for one of the organisms.

Question 50

In large natural ecosystems,competition between two species over time will usually result in

A)death of all the members of one species within a short time.
B)equal numbers of each species persisting for a long time.
C)each species occupying a slightly different niche.
D)hybridization between the two species,resulting in a third species.
E)alternating high numbers of each species as they constantly evolve mechanisms to out-compete each other.

Question 51

A population age structure diagram in which the birthrate is less than the death rate and the post-reproductive group is the largest would be best represented by a graph with a(n)

A)bell shape.
B)urn shape.
C)pyramid shape.
D)S-shaped curve.
E)J-shaped curve.

Question 52

Farmers sprayed leechi trees to suppress populations of scale insects.This also killed the populations of a predatory lacewing that controlled the numbers of scales.Soon the spraying did no good,and the damage to the leechi from the scales was greater than before spraying had occurred.Few predatory lacewings existed in the trees now because

A)they,too,are insects so they are opportunistic species.
B)both insects were equilibrium species and resistance was a matter of chance.
C)the predator was an opportunistic species and was therefore more susceptible to the spray.
D)the scale insect was an opportunistic species and the high number of young included a resistant strain; the predator was an equilibrium species and will take longer to produce a resistant variety.
E)they had reached their carrying capacity and thus their numbers decreased due to environmental resistance.

Question 53

Several species of grain beetles can live on dry meal,obtaining water mostly as metabolic water.Many of these beetle species are grain pests that do considerable damage to stored grain.You set up a dozen jars of dry meal and introduce 50 individuals of each species to each jar,being careful to have half of each species from each sex.The food supply is sufficient to last for a year and the size is adequate so that wastes do not become toxic.Most likely,examination of the jars in six months will find

A)a totally random variation in numbers of both beetles.
B)only one species per jar,similar to the classic competitive exclusion principle experiment with paramecia.
C)the same ratio of beetles as when you started,about half from each species.
D)only dead beetles in all jars due to intense competition for the niche.
E)half the jars with more of one species and the other half of the jars will have more of a second species of beetle.

Question 54

Which term describes the concept that no two species can have the same "job" in the community at the same time?

A)competitive exclusion
B)habitat
C)density-dependent factor
D)mimicry
E)symbiosis

Question 55

The role a species plays in the community is called its

A)habitat.
B)ecological niche.
C)biotic role.
D)abiotic role.
E)ecology.

Question 56

Interaction between two species as both attempt to use the same environmental resources is

A)competition.
B)a community.
C)an ecosystem.
D)predation.
E)symbiosis.

Question 57

Which of the following human populations would be expected to have the greatest increase in growth rate?

A)A population with the majority of their population over 50 years of age.
B)A population with its population distributed equally across all age ranges.
C)A population with most of its population under the age of 18 years of age.
D)A population with most of the population in middle age.
E)A population with most of its population over the age of 18 years of age.

Question 58

Interaction between two species in which one feeds on the other is

A)competition.
B)a community.
C)an ecosystem.
D)predation.
E)symbiosis.

Question 59

In an Asian rice paddy,carp eat decaying material from around the base of rice plants while a snail scrapes algae from the leaves,stems,and roots of the same plant.They can survive at the same time in the same rice paddy because they

A)occupy the same habitat but use the resources differently.
B)occupy the same habitat and use the same resources.
C)use the same resources but occupy different habitats.
D)occupy different habitats and use the resources differently.
E)work according to the competitive exclusion principle.

Question 60

Replacement reproduction cannot bring about zero population growth unless

A)all diseases such as cholera,typhus,and diphtheria are brought under control.
B)there are many fatalities due to a world war.
C)there are as many older women leaving the reproductive years as there are younger women entering them.
D)there are more older women leaving the reproductive years than there are younger women entering them.
E)there are fewer older women leaving the reproductive years than there are younger women entering them.

Question 61

Black-and-yellow stripes are a common warning coloration.Among a set of insects that possess black-and-yellow patterns are: -female wasps that sting
-male wasps that do not sting
-a tasty,harmless,and nutritious leaf beetle
-an acrid blister beetle that makes you sick if you eat it
-a harmless hover fly that sounds and looks like a bee
This assortment represents

A)all organisms that share black-and-yellow because it evolved in a common ancestor.
B)all cases of Batesian mimicry.
C)all cases of Müllerian mimicry.
D)a combination of cases including both Müllerian and Batesian mimicry.
E)warning coloration only in the cases of the female wasp and blister beetle; the other cases are not mimicry.

Question 62

In a pine forest,few other species of plants grow under the pines because the needles of pine trees are acidic and make the soil more acidic.This is an example of

A)the facilitation model.
B)the tolerance model.
C)the inhibition model.
D)an opportunistic model.
E)the climax model.

Question 63

Which would be the climax community in a biome that receives a large amount of rainfall?

A)plants with high tolerance to full sun,limited water,limited nutrients
B)the pioneer community
C)small native plants of the area such as grasses and herbs
D)large plants such as shrubs and trees
E)lichens,mosses,and ferns

Question 64

Which statement about parasitism is true?

A)The host is generally smaller than the parasite.
B)Parasites are always severe and kill the host.
C)All parasites require a single host for their life cycle.
D)There are examples of parasites in every kingdom of life.
E)All parasites will remain attached to their host for the entire life span of the host.

Question 65

An intimate relationship between two different species is called

A)competition.
B)a community.
C)an ecosystem.
D)predation.
E)symbiosis.

Question 66

In a population of 10,000 organisms over a one-year period there are 750 births and 130 deaths.Calculate the growth rate for that year.

A)0.062
B)0.055
C)0.088
D)0.013
E)0.075

Question 67

A form of symbiosis in which both participants benefit is

A)commensalism.
B)parasitism.
C)mutualism.
D)predation.
E)competition.

Question 68

The harmless orange-and-black viceroy butterfly closely resembling the toxic orange-and-black monarch butterfly is an example of

A)Müllerian mimicry.
B)Batesian mimicry.
C)both Müllerian and Batesian mimicry.
D)a case of resource partitioning.
E)a case of competitive exclusion.

Question 69

Consider the consequences of a harmless prey that evolves toward mimicry of a model that has an anti-predator defense-Batesian mimicry.What happens to the effectiveness of this defense as more and more prey in the population are harmless mimics? Then consider what happens when a species with bad taste evolves to resemble a model that stings (Müllerian mimicry).

A)The number of Müllerian mimics is limited because they dilute the protection afforded by the warning color pattern,but the addition of more Batesian mimics only strengthens the protective mimicry complex.
B)The number of Batesian mimics is limited because they dilute the protection afforded by the warning color pattern,but the addition of more Müllerian mimics only strengthens the protective mimicry complex.
C)The number of both Batesian and Müllerian mimics is limited because both dilute the protection afforded by the warning color pattern.
D)The number of both Batesian and Müllerian mimics is unlimited because they both reinforce the protection afforded by the warning color pattern.
E)The number of Batesian mimics is unlimited,but the addition of more Müllerian mimics dilutes the protective mimicry complex.

Question 70

The idea that plants cannot grow on a particular area until the soil has been developed enough by an earlier community is the

A)climax-pattern model.
B)facilitation model.
C)inhibition model.
D)tolerance model.
E)soil development model.

Question 71

A population of 100 butterflies living on an acre of land loses three-quarters of its members when a sudden freeze in the spring occurs just after they emerge as caterpillars.This population has undergone a reduction in population size due to

A)an intrinsic factor.
B)a density-independent factor.
C)a density-dependent factor.
D)natural selection.
E)an opportunistic control.

Question 72

Primary succession takes much longer than secondary succession because it involves

A)colonization by more equilibrium species.
B)time for weathering of rock and development of the soil horizons.
C)more time for development of a seed bank.
D)colonization by organisms that are farther away.
E)redevelopment of the atmospheric gases.

Question 73

You are on vacation in the Canadian Rocky Mountains and you observe that a massive forest fire has burned all the trees off the side of the mountain and sterilized the soil,leaving no topsoil.The type of succession that occurs following this type of fire is

A)secondary succession.
B)tertiary succession.
C)primary succession.
D)primary soil leaching.
E)facilitated succession.

Question 74

In a population of 150 organisms over a six-month period there are 75 births and 30 deaths.Calculate the growth rate for those six months.

A)0.7
B)0.5
C)0.2
D)0.3
E)0.75

Question 75

Which is NOT a parasitic relationship?

A)The Dutch elm disease fungus infects and kills elm trees.
B)The yellow fever virus causes fever and sometimes kills humans.
C)A female tick fastens to the skin of a human host and draws blood for nutrition to make her eggs.
D)The trichina worm burrows into muscle tissue,forms a cyst,and waits to continue its cycle until a predator consumes the host.
E)Unsightly dandelions sprout in a yard and compete with the fescue grass for sunlight.

Question 76

A population of 1,000 mice living in a barn loses one-half of its members when a sudden virus spreads through the population.This population has undergone a reduction in population size due to

A)an intrinsic factor.
B)a density-independent factor.
C)a density-dependent factor.
D)natural selection.
E)an opportunistic control.

Question 77

Parasites are found

A)only as viruses,bacteria,and protists.
B)only as viruses,bacteria,protists,and animals; no plants are parasites because they cannot move.
C)only on host animals.
D)only on one host where they can complete their life cycle and disperse to others of that same species.
E)in all kingdoms,and sometimes one parasite uses more than one host to disperse.

Question 78

An example of commensalism is

A)mycorrhizal fungal roots on the roots of plants.
B)ants living on the bullhorn acacia tree.
C)termites with protozoa in their digestive tracts.
D)flowering plants and their pollinators.
E)clown fishes in sea anemones.

Question 79

A form of symbiosis in which one participant benefits and the other apparently is not benefited nor harmed is

A)commensalism.
B)parasitism.
C)mutualism.
D)coevolution.
E)symbiosis.

Question 80

A small marine amphipod has recently been discovered that carries another organism on its back.The "backpack" organism tastes bad.If a fish ingests the pair,it immediately spits them back out.If the amphipod is alone,however,it is readily eaten and swallowed.There is no apparent benefit in this relationship for the "backpack" organism,which appears to be neither helped nor harmed.This is therefore a case of

A)mutualism.
B)parasitism.
C)commensalism.
D)competitive exclusion.
E)predation.