Deck 14: Ecology of Populations and Communities

Question 1

Several species of mice occupy the same meadow. One species remains near the stream; one is found almost exclusively among the dense undergrowth; and a third species is mainly seen in the open parts of the meadow. Since these three species of mice can coexist, they are probably demonstrating

A)competitive exclusion.
B)competitive inclusion.
C)symbiosis.
D)resource partitioning.
E)habitat division.

Answer 1

D

Question 2

Species that determine the structure of communities are called

A)climax.
B)keystone.
C)transitional.
D)crucial.
E)pioneer.

Answer 2

B

Question 3

A rapidly growing population is likely to have an age-structure diagram that is

A)bullet-shaped.
B)in the shape of an inverted pyramid.
C)shows significant bulges in the middle of the diagram.
D)constantly changing its shape.
E)in the form of a pyramid.

Answer 3

E

Question 4

When two species have overlapping niches and one species is excluded by the other, it is an example of

A)a fundamental niche.
B)competitive inclusion.
C)a realized habitat.
D)intraspecific competition.
E)competitive exclusion.

Question 5

Zero population growth refers to

A)a point at which the number of individuals entering the population is equal to the number exiting.
B)when the population size reaches zero.
C)when more individuals exit the population than enter.
D)the point at which the population size just starts to decrease.
E)a rapid increase in the population size.

Question 6

Which of the following is not an example of exponential growth?

A)a savings account that earns 2.5% interest each year for 10 years
B)the economy of a country that grows by 2% each year for 15 years
C)a child who saves one dollar each week for 10 years
D)bacteria that double their cell numbers every 30 minutes
E)a J- shaped curve

Question 7

The maximal growth rate of a population is called its

A)carrying capacity.
B)exponential growth.
C)logistic growth.
D)biotic potential.
E)fundamental niche.

Question 8

A life table

A)is used extensively by the insurance industry.
B)can be used to determine the exact year of death for an individual.
C)for humans does not take into account deaths from accidents.
D)has no predictive value.
E)determines the maximum age a human can reach.

Question 9

When a population reaches its carrying capacity,

A)more individuals will die than are born.
B)a large number of individual organisms will leave the population.
C)no more deaths or births can take place.
D)there is usually one or more factors limiting increased population growth.
E)new sources of nutrition must be found or the population will crash.

Question 10

The Human Population growth curve illustrates that

A)humans have reached their carrying capacity.
B)humans have exceeded their carrying capacity.
C)humans are experiencing exponential growth.
D)human population will crash.
E)humans do not have a carrying capacity.

Question 11

The first community to occupy a recently denuded region is referred to as

A)climax.
B)diversity.
C)pioneer.
D)mosaic climax.
E)transition.

Question 12

In the history of human population growth, the earliest stage is referred to as the

A)agricultural phase.
B)technological phase.
C)hunting and gathering phase.
D)industrial phase.
E)prehistoric phase.

Question 13

Factors that influence where a specific organism can be found include

A)competition with members of their own species.
B)physical factors found in the environment.
C)the age of the organism.
D)the number of female-to-male organisms.
E)the growth rate of the population.

Question 14

The primary cause of human population growth following the Industrial Revolution was

A)an increase in death rates.
B)a decrease in death rates.
C)an increase in birthrates.
D)a decrease in birthrates
E)more children being born to women over 35 years of age.

Question 15

The demographic transition is typically seen

A)when a country moves from an industrial phase into a more agricultural phase.
B)as developed countries use more resources.
C)when agriculture becomes more efficient.
D)when epidemics lead to high death rates.
E)as a country moves toward a more industrial phase.

Question 16

Density refers to the

A)average weight of individuals in a population.
B)ability of the population to adapt to the environment.
C)intelligence of the organism.
D)biomass of the population of organisms.
E)number of individuals per unit area.

Question 17

In this type of interaction, one organism is unharmed while the other benefits.

A)commensalism
B)mutualism
C)symbiosis
D)predation
E)parasitism

Question 18

Which of the following levels of ecological interaction are arranged from most inclusive to least inclusive?

A)community, biosphere, ecosystem, population
B)ecosystem, community, biosphere, population
C) population, community, ecosystem, biosphere
D)ecosystem, biosphere, community, population
E)biosphere, ecosystem, community, population

Question 19

Which of the following organisms is likely to show a late-loss survivorship curve?

A)mussel
B)flowering plant
C)squirrel
D)elephant
E)sea turtle

Question 20

In humans, fertility curves

A)determine the number of individuals entering a population.
B)represent reproduction rates versus age of population members.
C)do not change throughout the reproductive years.
D)are important for females and males.
E)do not affect population size.

Question 21

Prey organisms use varied strategies to try to avoid being eaten. List some of these strategies.

Question 22

Timber wolf populations are partially controlled by wolf behavior. For example, wolves form packs and are territorial. Therefore, only a finite number of wolves will comprise a pack and occupy a relatively large territory. Which of the following best describes this type of population-regulating mechanism?

A)competitive exclusion mechanism
B)niche-controlling mechanism
C)habitat-controlling mechanism
D)extrinsic mechanism
E)intrinsic mechanism

Question 23

A fire has swept through a mature forest and devastated the area. Virtually all vegetation is burned and considered a complete loss. Foresters, however, realize that plants will soon colonize the area starting the successional process that will eventually restore the forest. Will the pioneer plants that first colonize the area most likely be r-selection strategists or K-selection strategists? Explain your answer.

Question 24

One hundred thousand years ago a population of rodent species migrated into a new environment and experienced little competition for resources. Today, this species is still surviving in this environment, but competition from other species has decreased its choices for food and has limited the species to a smaller home range. When the species first migrated into this new environment it filled its _________________ niche, whereas, 100,000 years later it experienced its ____________ niche.

A)realized; fundamental
B)fundamental; realized
C)intrinsic; realized
D)extrinsic; fundamental
E)intrinsic; extrinsic

Question 25

Which of the following is most likely to follow an irruptive (boom and crash)growth curve?

A)elephants
B)humans
C)hippopotami
D)moose
E)insects

Question 26

If you were to include all of your college campus, the buildings, the parking lots, the walkways, the green areas, the students, the staff, the various other living organisms living there, you would be describing a(n)

A)ecosystem.
B)population.
C)biosphere.
D)community.
E)sere.

Question 27

Which age structure diagram would be most indicative of the African country of Kenya?

A)pyramid-shaped with a wide base
B)bullet-shaped
C)middle section wider than both the relatively narrow base and top
D)tapering from a broad top to a narrow bottom
E)base and top both wider than the constricted center

Question 28

Coevolution would be expected to occur between all of these relationships except

A)predator and prey.
B)parasite and host.
C)mutualistic relationships.
D)interspecific competitors.
E)commensal relationships.

Question 29

When the ring-necked pheasant was introduced from China to the United States, it increased in population, stabilized, and did not appear to cause any detrimental effects on the populations of any of the plants or animals in the regions in the Midwest where it lives. Therefore, it probably

A)filled a realized niche previously occupied by another bird.
B)filled a fundamental niche previously not occupied.
C)experienced extensive competitive exclusion.
D)experienced density-dependent limiting factors.
E)experienced extreme density-independent limiting factors.

Question 30

The carrying capacity of white-tailed deer in a certain habitat is 10 deer/km². The deer population is presently 5 deer/ km². Which of the following predictions is most likely for this deer population?

A)A population decrease.
B)A population increase.
C)A population that will remain at 5 deer/ km².
D)A population that will reach 30 deer/ km² and then experience a crash.
E)A population that will be controlled by intrinsic regulating mechanisms.

Question 31

A survivorship curve similar in shape to that seen in humans might be expected to be seen in

A)elephants.
B)domestic cows.
C)whales.
D)a rhinoceros.
E)any of the above.

Question 32

Current research indicates that species richness increases proportionately with the

A)number of plants in the region.
B)latitude.
C)longitude.
D)amount of resources available.
E)stage of succession.

Question 33

Lichens, a combination of fungi and certain algae, live together in a close community interaction. The traditional understanding of lichen is one where the algae produces food for the fungi and the fungi supply the algae with a suitable home. Recently, however, it was found that the algae can live just fine on their own and are also found living "alone" in nature. The fungi on the other hand do not appear to live on their own in the "wild." Which type of interaction characterizes the "traditional" understanding of lichen? Why? Which type of interaction does the new research suggest? Why?

Question 34

In 1990, a small herd of white-tailed deer migrated into a new environment. Research indicated that the herd has reproduced exponentially with a doubling time of 5 years. It was estimated that this herd would reach its carrying capacity by 2005. In what year would the herd be "half way" to its carrying capacity? Explain.

Question 35

Define niche. Based on your definition, describe the niche of the yellowtail flounder.

Question 36

Match the following ecological terms with the correct description.
11. __ A relatively stable grouping of plants and animals
12. __ The total number of species found in a community
13. __ The maximum reproductive capacit
14. __ The propartion of a population that lives to a certain age
15. __ One species benefits while another is neither harmed nor helped
A. climax communit
B. swvivorship curve
C. species richness
D. biotic potential
E. commensalism

Question 37

The number of offspring an individual organism could have under optimal conditions is called the

A)biotic potential.
B)fertility rate.
C)life expectancy.
D)carrying capacity.
E)fecundity.

Question 38

Match the following ecological principles with the population curve.
17. __ exponential growth
18. __ reflect the biotic potential of the organism
19. __ growth often followed by a crash in the population
20. __ takes into consideration the carrying capacity
21. __ seen in populations with no density-dependent death factors
A. S-shaped curves
B. J-shaped curves

Question 39

Four primary factors affect the size of a population of a particular species. Which of these is not one of those major factors?

A)deaths
B)births
C)mitigation
D)emigration
E)immigration

Question 40

Do predators control prey? Or do prey control predator populations? Explain your answer.

Question 43

Species diversity is decreasing on the planet and has been identified as a major problem by many ecologists. Therefore, it is important for scientists to identify habitats that support diversity and to reconstruct environments for maximum diversity. Describe an environment that would support a high species richness.

Question 44

Applying what you know about animal populations that would exhibit an S-shaped population curve, what are some life history characteristics you would expect to see in this species?

Question 45

Explain the concept of a keystone species.

Question 47

Both low birth and death rates characterize the demographic transition. Which factors will lower birth and death rates for twenty-first century Homo sapiens?

Question 48

Discuss a number of actions that could limit the biotic potential of the yellowtail flounder.

Question 50

We consider the crash of the groundfish populations off the coast of Cape Cod as an example of ecosystem collapse due to mankind's negligence. How might this forecast our future?

Question 51

Characterize the demographic transition seen in the human population. When did it occur?

Question 52

Briefly describe the coevolution of predators and prey. Does this concept apply to parasites and hosts?

Question 53

Describe the second phase of the growth of the human population.

Question 54

It is stated in Chapter 14 that "for people, an average of 2.1 children per couple results in zero population growth." Explain why it may take several generations to reach zero population once "people average" 2.1 children.