Deck 11: Competition

Question 1

Which of the following is not characteristic of interspecific competition?

A) One or more resources is limiting.
B) The population size of at least one species decreases.
C) The limiting resource does not change over time.
D) Two or more species interact.
E) none of the above

Answer 1

C

Question 2

Connell concluded that Semibalanus and Chthamalus compete because

A) Semibalanus cannot survive in the lower intertidal.
B) removal of Semibalanus led to colonization by Chthamalus.
C) Chthamalus is able to live high and low in the intertidal.
D) he found that space is not limiting.
E) none of the above

Answer 2

B

Question 3

The null hypothesis in a deWitt replacement experiment

A) assumes that interspecific and intraspecific competition are equivalent.
B) determines the outcome of the experiment.
C) assumes that interspecific competition is greater than intraspecific competition.
D) assumes that intraspecific competition is greater than interspecific competition.
E) none of the above

Answer 3

A

Question 4

Diffuse competition

A) is the result of diffuse resources.
B) occurs when one species preempts space.
C) is the result of many competitors.
D) is the result of a single dominant competitor.
E) none of the above

Question 5

Which of the following does not directly affect the intensity of competition?

A) the presence of similar species
B) niche overlap
C) niche breadth
D) the density of competitors
E) none of the above

Question 6

According to the competitive exclusion principle,

A) resources exclude competitors
B) intraspecific competitors exclude interspecific competitors
C) two species can occupy the same realized niche.
D) two species cannot coexist on the same limiting resource.
E) none of the above

Question 7

Character displacement

A) is the result of selection to decrease niche overlap.
B) is the result of selection to increase niche breadth.
C) is the result of disruptive selection.
D) requires diffuse competition.
E) none of the above

Question 8

Adaptive radiations are likely to occur

A) when species face increased competition.
B) when competition decreased competition.
C) only on islands.
D) after islands are connected to the mainland.
E) none of the above

Question 9

The term α₂₁N₁ measures the

A) degree to which species 1 reduces the resources available to species 2.
B) degree to which species 2 reduces the resources available to species 1.
C) carrying capacity for species 1.
D) carrying capacity for species 2.
E) none of the above

Question 10

The value of niche overlap (α₂₁N₁) increases when the

A) proportional use of the resource by species 1 and 2 are different.
B) proportional use of the resource by species 1 and 2 are similar.
C) squared resource use is 1.0.
D) carrying capacity changes.
E) none of the above

Question 11

In the Lotka-Volterra graphs, an isocline determines

A) where each species is isolated.
B) the rate of change of competition.
C) where population growth is zero.
D) where population growth is maximal.
E) none of the above

Question 12

The Lotka-Volterra models show that coexistence is more likely if niche overlap is

A) small and the carrying capacities are different.
B) large and the carrying capacities are similar.
C) small and the carrying capacities are similar.
D) is similar and the carrying capacities are different.
E) none of the above

Question 13

The realized niche

A) is an adaptive response to competition.
B) is the immediate effect of a competitor on the fundamental niche.
C) is always larger than the fundamental niche.
D) evolves over many generations.
E) none of the above

Question 14

Self-thinning

A) occurs when different tree species compete.
B) is the increase in population size and decrease in individual size.
C) is the decrease in population size and increase in individual size.
D) prevents overpopulation.
E) none of the above

Question 15

In a deWitt replacement series, the most intense interspecific competition occurs when

A) the null hypothesis is rejected.
B) the numbers of individuals of the two species are equal.
C) the numbers of individuals of the two species are most different.
D) if the performance of one species is the same as that of the other.
E) none of the above

Question 16

The songs of black-capped and mountain chickadees

A) both shift by character displacement in sympatry.
B) do no shift by character displacement in sympatry.
C) shift by character displacement only in the subordinate species.
D) shift by character displacement in allopatry.
E) none of the above

Question 17

When the land bridge formed between North and South America,

A) character displacement occurred.
B) marsupials invaded North America.
C) placental mammals invaded North America.
D) placental carnivores drove some marsupials extinct.
E) none of the above

Question 18

Competition occurs only between related taxa.

Question 19

Semibalanus and Chthamalus compete for light resources.

Question 20

Disturbance can reduce the intensity of competition.

Question 21

Competitive exclusion occurs if niche overlap is too large.

Question 22

The fundamental niche is the role of the organism in the environment.

Question 23

Species that are allopatric cannot compete.

Question 24

Fugitive species are poor competitors

Question 25

Lotka-Volterra isoclines must be straight lines.

Question 26

Character displacement is the result of reduced competition.

Question 27

When disturbance is frequent, competition is often less intense.

Question 28

In __________ competition one species reduces the resource available to the other; in __________ competition one species reduces access to the resource.

Question 29

The functional niche is the __________ whereas the __________ is set of biological and physical resources that determine fitness.

Question 30

What are the conditions that lead to coexistence in the Lotka-Volterra model?

Question 31

To demonstrate that competition is occurring one must show that __________.

Question 32

Directional selection on the niche to reduce overlap leads to __________.

Question 33

When competition occurs, the realized niche is __________ than the fundamental niche.

Question 34

Why is the carrying capacity difficult to measure?