Deck 44: Population Ecology

Question 1

Identify the distribution patterns of the desert shrubs in each picture.

Answer 1

A.clumped B.random C.uniform

Question 2

When discussing population features,a cohort is described as

A)all the individuals in a population born at the same time.
B)all individuals living in the same habitat.
C)all the different species in a community.
D)all the organisms interacting in the ecosystem.
E)All of the choices are correct.

Answer 2

A

Question 3

Opportunistic species

A)are composed of large individual organisms.
B)are good dispersers and colonizers of new habitats.
C)are slow to mature.
D)have long life spans.
E)are adapted to stable environments.

Answer 3

B

Question 4

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 not survived).What is the growth rate of this population?

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)None - because there is exact replacement of the previous generation
D)2,000 - because there was this much average die-off per year
E)20,000 - because there were that many eggs produced per parent fish (r²)

Question 5

The maximum rate of natural increase of a population that occurs under ideal conditions is the

A)population growth.
B)biotic potential.
C)environmental resistance.
D)carrying capacity.
E)density-independent population.

Question 6

Which of the following factor(s)limit(s)exponential growth of a population?

A)limited resource availability
B)increases in predator populations
C)competition between members
D)competition with other species
E)All of these choices limit exponential growth.

Question 7

Tell what type of growth model is depicted in the graph and describe the factors that must be met for a population to experience this type of growth.Identify the labeled phases "A," "B," "C," and "D" and briefly explain what occurs during these phases.

Question 8

Which of the following studies would lie outside of an ecologist's skill set?

A)Studying the progression of an outbreak of HIV in sub-Saharan Africa.
B)Developing a management plan for the preservation of an endangered species.
C)Proposal to develop a solar power field on the edge of a major urban area.
D)Management plan to clean up a section of the Mississippi River that has become polluted due to sewage discharge.
E)All of these are part of an ecologist's skill set.

Question 9

The population growth rate is negative when

A)birthrate is greater than death rate.
B)death rate is greater than birthrate.
C)all couples are married but average fewer 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

An ecologist may study

A)the human impact on the Earth's environment.
B)the different types of organisms living near a hydrothermal vent and how they interact.
C)the effect of a particular pesticide on a food chain.
D)how populations are restricted by environmental resistance.
E)All of the choices are correct.

Question 11

Population size levels off at the ________ of an environment.

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

Question 12

Bangladesh has 2,596 persons per square mile,while the United States has 780 persons per square mile and Canada has 9 persons per square mile.These statistics compare the ________ of these countries.

A)population densities
B)population distributions
C)carrying capacities
D)rate of natural increase
E)limiting factors

Question 13

Tell what type of growth model is depicted in the graph and describe the factors that must be met for a population to experience this type of growth.Identify the labeled phases,"A" and "B," and briefly explain what occurs during these phases.

Question 14

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 15

All of the following factors will keep a population from growing at its biotic potential EXCEPT

A)limited supply of food and water.
B)lack of space.
C)abundance of predators.
D)prevalence of disease or parasites.
E)successful reproduction of its members.

Question 16

In the logistic growth curve formula,when N is very large,(K-N)/N is almost equal to 0,which results in

A)the population growing as fast as it can,or r(N).
B)the population growth slowing to zero.
C)the population exceeding carrying capacity; more are dying due to starvation than are born.
D)the population going extinct.
E)You can't tell without knowing the value of r (rate of reproduction).

Question 17

A pond represents a(n)________,while the minnows represent a(n)________.

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

Question 18

The particular place where an organism lives is its

A)life zone.
B)niche.
C)ecosystem.
D)community.
E)habitat.

Question 19

A type II survivorship curve,drawn by plotting the number of individuals in a given population alive at the beginning of each age interval,is characterized by

A)most individuals dying of old age.
B)many individuals dying early in life.
C)individuals dying at a constant rate throughout time.
D)most individuals dying during their reproductive years.

Question 20

All of the following statements about population distribution are true EXCEPT

A)population distribution is the pattern of dispersal of individuals across an area of interest.
B)environmental conditions,such as climate and altitude,are often limiting factors of distribution.
C)a population's distribution is calculated as the number of individuals per unit area.
D)behavioral traits,such as territoriality,can affect the distribution pattern of a population.

Question 21

Which of the following circumstances would cause exponential growth to move into a logistic growth phase?

A)a reduction in the number of females within the population
B)a large increase in the population over three generations
C)the introduction of a non-native predator into the environment
D)habitat alteration resulting in the conversion of 1,200 acres of forests into agricultural fields and housing developments
E)All of these would cause exponential growth to move into logistic growth.

Question 22

A(n)________ consists of all the populations of multiple species interacting in a designated region.

A)ecosystem
B)community
C)biosphere
D)None of the choices are correct.

Question 23

From the perspective of population growth,what three major age groups does a population contain? Draw three age structure diagrams that roughly depict the proportion of these three age groups in an increasing population,a stable population,and a decreasing population.

Question 24

Only the LDCs will be experiencing overpopulation growth in the near future.

Question 25

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

A)they,too,are insects so they are r-selected.
B)the scale insect was K-selected and the high number of young included a resistant strain,while the predator was r-selected and will take longer to produce a resistant variety.
C)the predator was r-selected and was therefore more susceptible to the spray.
D)the scale insect was r-selected and the high number of young included a resistant strain; the predator was K-selected and will take longer to produce a resistant variety.

Question 26

Which of these diagrams represents an age structure diagram of more-developed countries?

A)Diagram A
B)Diagram B

Question 27

The sequence of decreased death rate followed by a decrease in birthrate is called

A)environmental resistance.
B)a limiting factor.
C)doubling time coefficient.
D)demographic transition.
E)replacement reproduction.

Question 28

Many species are held below the environmental carrying capacity by predation.

Question 29

A population in which death rates are higher than birth rates,and the prereproductive group is smaller than the reproductive group,is best represented by an age structure diagram with a(n)________-shape.

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

Question 30

Most species are intermediate between r-strategists and K-strategists,and tend to have a type II survivorship curve.

Question 31

Which of the following lifestyle changes would have the greatest impact on reducing an individual's environmental impact?

A)Reducing your meat consumption to once or twice a week.
B)Buying a more fuel-efficient vehicle and only using it when you are taking long trips instead of traveling locally.
C)Downsizing and moving into a smaller house.
D)Reducing the number of children in your household to reach a zero population growth rate.
E)Waiting until later in life to have children and only having one per couple.

Question 32

As the carrying capacity of an environment is approached by a population,

A)births begin to exceed deaths.
B)deaths begin to exceed births.
C)the rate of reproduction increases.
D)population growth begins to be exponential.
E)density-dependent environmental resistance increases.

Question 33

In a population with low death rates,this age structure diagram indicates that

A)the population is decreasing.
B)the population is stable.
C)the biotic potential must be larger than usual.
D)the population will continue to grow for some time.

Question 34

In trying to limit the growth of a pest,you will have more success if you can reduce the carrying capacity of the environment rather than reduce the population size of the pest.

Question 35

If the members of a population are small in size,mature early,and have high parity and fecundity,they are

A)K-strategists.
B)r-strategists.
C)neither K-strategists nor r-strategists,but have characteristics of both.

Question 36

Density-independent factors which play a role in regulating population size in nature include

A)weather.
B)natural disasters.
C)geographical barriers.
D)All of the choices are correct.

Question 37

Since the population of the LDCs is still growing at a significant rate,one would correctly assume that the LDCs consume a much larger proportion of the Earth's resources.

Question 38

Which variable is not a density-dependent factor?

A)competition between two male deer for territory
B)a red-tailed hawk preying upon a population of field mice
C)smallpox outbreaks during the 1800s
D)an early cold spell that causes the plants in a given area to die off earlier than normal

Question 39

Intrinsic factors,such as behavior and physiology,may affect growth rates of a population.

Question 40

In the near future,the human population is predicted to involve

A)a worldwide decrease in population growth due to limited resources.
B)an increase in population growth in all countries in the world.
C)a decrease in growth in most,but not all,more-developed countries and continued growth in most less-developed countries.
D)a continuation of human population growth at the same pace as in the previous century.

Question 41

When the number of births plus immigration exceeds the number of deaths plus emigration,a population size will increase.

Question 42

Dandelions and tent caterpillars,which are r-strategists,are examples of opportunistic species that tend to move in high numbers and rapidly occupy new environments.

Question 43

The basic level of an ecological study always begins by looking at how populations interact with each other.

Question 44

How is environmental impact measured in a population?

A)population size and resource consumption
B)population size and resource production
C)number of individuals dying each generation plus birthrates
D)All of these are used to measure environmental impact.
E)None of these are used to measure environmental impact.

Question 45

Researchers have discovered that there is a small remnant population of endangered bluegrass left in a small prairie plot outside of Kansas City.If there are approximately 850 individuals in the cohort,how many individuals can the researchers expect to find alive at the end of the summer,6 months later?

A)approximately 1,000
B)approximately 330
C)approximately 700
D)approximately 45
E)None of the individuals will be alive 6 months later.

Question 46

Survivorship may be defined as the probability of newborn individuals of a cohort surviving to a particular age interval or as the proportion of the population surviving from the previous age interval.

Question 47

Zero population growth will be achieved as soon as couples have only replacement reproduction,with two children per couple.

Question 48

Parasitism,competition,and predation are density-independent factors that help control population size.

Question 49

What is the age structure diagram for a population that has a birthrate higher than its death rate and larger population in prereproductive ages than in reproductive and postreproductive ages?

A)This population can expect to see a pyramid-shaped diagram that will cause the population to grow in the near future.
B)This population can expect to see an urn-shaped diagram that will cause the population to grow in the future.
C)This population can expect to see a bell-shaped diagram that will cause the population to grow in the future.
D)This population can expect to see a pyramid-shaped diagram that will cause the population to decrease in the future.
E)This population can expect to move into a logistic growth curve in the near future.