Deck 9: Population Regulation

Question 1

The effect of wolves on elk in Yellowstone is an example of

A) a bottom-up interaction.
B) a top-down interaction.
C) symbiosis.
D) trophism.
E) none of the above

Answer 1

B

Question 2

Which of the following are characteristics of biological control agents?

A) a broad host range
B) low reproductive pontential
C) life-cycle synchrony
D) bottom-up control
E) none of the above

Answer 2

C

Question 3

In the equation dN/dt = rN(1-N/K),

A) r is the net reproductive rate.
B) K is the carrying capacity.
C) dN/dt is simplified to N/t.
D) the term 1-N/K models top-down effects.
E) none of the above

Answer 3

B

Question 4

Density-independent factors

A) are always bottom-up.
B) never reach equilibrium.
C) are stronger than density-dependent factors.
D) depend on the value of K.
E) none of the above

Question 5

Population stability

A) is the same as equilibrium.
B) always precedes equilibrium.
C) requires density-independent factors.
D) occurs when the population remains within narrow limits.
E) none of the above

Question 6

The classic lynx-hare population data show that

A) equilibrium eventually occurs.
B) bottom-up and top-down factors both occur.
C) regulation is density-independent.
D) density-dependence leads to population stability.
E) none of the above

Question 7

The population dynamics of lemmings demonstrate that

A) fitness is a property of the population.
B) population regulation by suicide is not an evolutionarily stable strategy (ESS).
C) self-regulation is impossible in nature.
D) lemmings are regulated by top-down mechanisms.
E) none of the above

Question 8

Self-regulation of populations requires

A) long-term stability.
B) density-dependent effects on physiology.
C) density-independent effects on physiology.
D) top-down factors.
E) none of the above

Question 9

In a metapopulation

A) the landscape is irrelevant.
B) immigration always equals emigration.
C) populations habitats of different quality.
D) populations are completely isolated.
E) none of the above

Question 10

The value of the carrying capacity (K)

A) varies over time.
B) determines the rate of immigration.
C) is a measure of population stability.
D) varies with the value of r.
E) none of the above

Question 11

Population regulation is related to Darwin's theory of evolution by selection because

A) populations achieve stability.
B) selection is generally top-down.
C) selection is generally bottom-up.
D) populations growth is limited.
E) none of the above

Question 12

Population equilibrium by density-dependent mechanisms

A) is rare in nature.
B) is common in nature.
C) requires that K vary with N.
D) requires self-regulation.
E) none of the above

Question 13

In group selection,

A) altruism cannot evolve.
B) fitness is a property of the individual.
C) fitness is a property of the group.
D) the concept of the ESS does not apply.
E) none of the above

Question 14

Chance affect populations

A) in metapopulations.
B) when density-independent factors are important.
C) when density-dependent factors are important.
D) if the population is to achieve equilibrium.
E) none of the above

Question 15

Which of the following do(es) not affect the moose population on Isle Royale?

A) weather
B) top-down effects
C) carrying capacity
D) parasites
E) none of the above

Question 16

Additive mortality

A) proportionally increases the total mortality rate.
B) proportionally decreases the total mortality rate.
C) adds dispersal to mortality factors.
D) replaces compensatory mortality.
E) none of the above

Question 17

The variable K in the growth equation

A) is a measure of the mortality rate.
B) is a measure of compensatory mortality.
C) may vary over time and space.
D) never varies in real ecosystems.
E) none of the above

Question 18

Density-independence leads to population equilibrium.

Question 19

Density-dependence can result from top-down or bottom-up factors.

Question 20

Population equilibrium and population stability are the same.

Question 21

Most populations are regulated by a single factor.

Question 22

Crowding and stress factors do not violate the requirements of an ESS.

Question 23

The values of e (emigration) and i (immigration) can be density-dependent.

Question 24

Lynx exert bottom-up control of hares.

Question 25

Density-dependent factors outweigh density-independent factors in most populations.

Question 26

Random factors play no role in metapopulations.

Question 27

Metapopulations fluctuate less than the populations that comprise them.

Question 28

__________ refers to population fluctuations within narrow limits.

Question 29

What do the lynx-hare data suggest about density-dependence and population stability?

Question 30

Long-term population studies are important because they show that __________.

Question 31

In the checkerspot butterfly metapopulation, populations are associated with __________.

Question 32

The metapopulation structure of Adelie penguins is dependent on __________.

Question 33

In density dependent mortality, the mortality rate is __________ (positively; negatively) related to population size.

Question 34

Is it possible for abiotic factors to affect the population in a density-dependent fashion?