Question 1

The competitive exclusion principle states that
A) it is not possible for two species with different niches to coexist.
B) it is not possible for two species with the same niche to coexist.
C) it is possible for two species with different niches to coexist.
D) it is possible for two species with the same niche to coexist.

Accepted Answer

The competitive exclusion principle states that it is not possible for two species with the same niche to coexist, because they will compete for the same resources until one species outcompetes and eliminates the other.

Question 2

What is the main difference between asymmetric competition and symmetric competition?
A) Competition is barely measurable in symmetric competition.
B) One species is outcompeted completely in asymmetric competition.
C) The fitness reduction is roughly equal between each species in symmetric competition.
D) None of the above answers applies.

Accepted Answer

In symmetric competition, both species experience a roughly equal reduction in fitness, while in asymmetric competition, one species outcompetes the other completely. Option A is incorrect as symmetric competition may still result in measurable competition. Option B is partially correct, but it is not necessarily true that one species is completely outcompeted in all cases of asymmetric competition. Option D is not a valid answer.

Question 3

Figure 52.5
-In the figure above, the labelled groups, which group is displaying Batesian mimicry?
A) group A
B) group B
C) both groups A and B
D) none of the above groups

Accepted Answer

B

Question 4

While traveling in Texas, you stumble across a snake with red, yellow, and black bands. You somehow remember that this could be a poisonous coral snake or a harmless milk snake, but you forget how to differentiate them because they both have similar colours and banding patterns. You wisely decide not to pick up the snake. What defence was successful in preventing you from grabbing the snake?
A) Batesian mimicry
B) inducible defences
C) Müllerian mimicry
D) constitutive defence
E) none of the above

Accepted Answer

Batesian mimicry is a form of mimicry where a harmless species has evolved to imitate the warning signals of a harmful species directed at a predator of them both, which is what the milk snake does by mimicking the coloration of the venomous coral snake.

Question 5

Some birds follow moving swarms of army ants in the tropics. As the ants march along the forest floor hunting insects and small vertebrates, birds follow and pick off any insects or small vertebrates that fly or jump out of the way of the ants. This is an example of what kind of species interaction?
A) consumption
B) commensalism
C) mutualism
D) parasitism
E) competition

Accepted Answer

This is an example of commensalism because the birds benefit from the ants' hunting activities without harming or benefiting the ants. The birds get food by catching prey that is flushed out by the moving ant swarm, but the ants neither gain nor lose from this interaction.

Question 6

Figure 52.1
-In looking at the figure above, what conclusions can be drawn?
A) Both species compete for all sizes of seeds other than those of intermediate size.
B) Both species compete for seeds of intermediate size.
C) Both species compete for all sizes of seeds.
D) Both species eat all sizes of seeds.

Accepted Answer

The figure shows that the two species have a similar distribution of beak depths and that they overlap in their consumption of seeds of intermediate sizes. Therefore, it can be concluded that both species compete for seeds of intermediate size. There is no evidence or information to suggest that the two species compete for all sizes of seeds or that they eat all sizes of seeds.

Question 7

Figure 52.3
-In the figure above, which species is the stronger competitor?
A) species 1
B) species 2
C) Both species compete equally.
D) It is not possible to tell from this figure.

Accepted Answer

Species 1 has a higher carrying capacity than species 2, which means that it can support a larger population size at equilibrium. This indicates that species 1 is the stronger competitor.

Question 8

Figure 52.4
-Based on the figure above, what result would you expect if you replaced the crabs with broken mussel shells?
A) a higher degree of difference than the crab experiment
B) the same result as the experiment with crabs
C) impossible to hypothesize
D) no difference in shell thickness

Accepted Answer

Replacing crabs with broken mussel shells in the experiment would likely yield the same result as the original experiment with crabs, assuming the broken mussel shells serve a similar role in selecting for thicker shells through predation or environmental pressure.

Question 9

Some birds follow moving swarms of army ants in the tropics. As the ants march along the forest floor hunting insects and small vertebrates, birds follow and pick off any insects or small vertebrates that fly or jump out of the way of the ants. What is the specific benefit relationship?
A) Birds benefit from the association and harm the ants.
B) Birds and ants benefit from the association.
C) Birds do not benefit from the association, but the ants do.
D) Birds benefit from the association, but have no impact on the ants.
E) Neither birds nor ants benefit from the association.

Accepted Answer

Birds benefit by getting an easy meal from the insects and small vertebrates that are flushed out by the moving ants, but this behavior does not negatively impact the ants, thus the ants are neither harmed nor benefited directly by the birds' actions.

Question 10

In the hypothesis that C. stellatus a species of barnacle) is competitively excluded from the lower intertidal zone by B. balanoides another species of barnacle), what could be concluded about the two species?
A) The fundamental and realized niches of B. balanoides are identical, but the fundamental and realized niches of C. stellatus are different.
B) The fundamental and realized niches of B. balanoides and C. stellatus are both identical.
C) The fundamental and realized niches of B. balanoides and C. stellatus are both different.
D) The fundamental and realized niches of B. balanoides are different, but the fundamental and realized niches of C. stellatus are identical.

Accepted Answer

If C. stellatus is competitively excluded from the lower intertidal zone, it suggests that B. balanoides is a superior competitor for resources in that zone. Therefore, the fundamental niche (the complete range of environmental conditions and resources that a species can exploit) of B. balanoides likely overlaps with the realized niche (the actual range of environmental conditions and resources that a species occupies) of C. stellatus. However, C. stellatus may still have a different fundamental niche that includes other environmental conditions and resources that are not present in the lower intertidal zone, which could explain why it is not present there despite not being directly prevented from occupying it by any physical or chemical factors.

Question 11

Which hypothesis supports the observation that herbivores do not generally eat all of the available plants?
A) plant- defence hypothesis
B) poor nutrition hypothesis
C) top- down control hypothesis
D) a combination of all of the above
E) none of the above

Accepted Answer

The observation that herbivores do not generally eat all of the available plants can be explained by a combination of hypotheses: the plant-defense hypothesis (plants have evolved defenses to deter herbivores), the poor nutrition hypothesis (not all plants provide sufficient nutrition), and the top-down control hypothesis (predators limit herbivore populations).

Question 12

Which of the following is not a type of consumption?
A) herbivory
B) parasitism
C) mutualism
D) predation

Accepted Answer

Herbivory, parasitism, and predation are all types of consumption in which one organism feeds on another. Mutualism, on the other hand, is a type of interaction in which both organisms involved benefit from the interaction, and does not involve one organism consuming another.

Question 13

Figure 52.2
-What is the term used to describe the process shown in the panels in the figure above?
A) competition
B) species interaction
C) niche realization
D) niche differentiation

Accepted Answer

The process shown in the panels is niche differentiation, which describes the process by which competing species use the environment differently in a way that allows them to coexist. We can see that each species is utilizing the environment in slightly different ways in order to reduce overlap and avoid direct competition.

Question 14

Refer to the grids below to answer the following question.

According to the Shannon Diversity Index, which of the five grids provided, with each one containing 36 square show the greatest diversity?
A) 1
B) 2
C) 3
D) 4
E) 5

Accepted Answer

The answer of Refer to the grids below to answer...

Question 15

Figure 52.1
-According to the figure above, which species is more successful in competing for seeds?
A) species 1
B) species 2
C) These species do not compete for seeds.
D) This figure does not illustrate which species is more successful.

Accepted Answer

Without a figure, it's impossible to determine which species is more successful in competing for seeds.

Question 16

What is a likely reason for the observation that there are more species in tropical areas than in places more distant from the equator?
A) more frequent ecological disturbances
B) fewer predators
C) more intense annual solar radiation
D) fewer agents of disease

Accepted Answer

Tropical areas receive more intense annual solar radiation than areas further from the equator. This leads to warmer temperatures, higher year-round productivity, and more opportunities for speciation.

Question 17

Snails typically avoid sunlit areas, but some snails infected with certain parasites become attracted to light and prefer sunlit areas. Which of the following is the most likely hypothesis given the life cycles of many parasites?
A) The parasite must exit the snail in a sunlit area in order to move and find its next host.
B) The snail is dying from the parasite and is therefore looking for the light.
C) The parasite itself must be exposed to light in order to survive in the snail.
D) The parasite manipulates the behaviour of the snail so that it gets eaten more readily, which allows the parasite to complete its life cycle.
E) The snail is behaving differently in order to rid itself of the parasite.

Accepted Answer

This is known as the "manipulation hypothesis," which suggests that parasites evolve to manipulate the behavior of their hosts in ways that increase the likelihood that the parasites will be transmitted to their next host. In this case, the parasite is manipulating the behavior of the snail to increase the chances that the snail will be eaten and the parasite will be able to continue its life cycle.

Question 18

Figure 52.4
-What conclusion can you draw from the figure above?
A) Mussels can sense the presence of crabs only visually.
B) Without direct contact, mussels can sense the presence of crabs.
C) Shell thickness is a non- inducible defense.
D) Mussels are increasing their shell thickness in response to water current.

Accepted Answer

The figure shows that mussels respond to the presence of crabs even without direct contact, indicating that they can sense them through other means, such as chemical cues in the water. This supports choice B. None of the other choices are supported by the figure.

Question 19

Figure 52.5
-In the figure above, which of the following statements is true?
A) All of the species of insects shown are in the order Hymenoptera.
B) There are no true mimics in the insects shown.
C) Half of the insects shown are harmless.
D) All of the insects are displaying Batesian mimicry.

Accepted Answer

Half of the insects shown are likely to be harmless, as Batesian mimicry involves harmless species mimicking the warning signals of harmful species to avoid predation. Without seeing the figure, this answer is based on common principles of mimicry in insects.

Question 20

Which would be the best way to directly test the hypothesis that C. stellatus a species of barnacle) is competitively excluded from the lower intertidal zone by B. balanoides another species of barnacle)?
A) Place individuals of each species in a jar and see which species survives.
B) Clear rocks in an entire area and document recolonization events.
C) Transplant B. balanoides to the upper intertidal zone.
D) Remove all C. stellatus from the upper tidal zone.
E) Remove all B. balanoides from the lower intertidal zone.

Accepted Answer

Removing all B. balanoides from the lower intertidal zone directly tests the hypothesis by observing if C. stellatus can occupy the zone in the absence of B. balanoides, indicating competitive exclusion.

Quiz 52: Community Ecology

The competitive exclusion principle states that

What is the main difference between asymmetric competition and symmetric competition?

Figure 52.5 -In the figure above, the labelled groups, which group is displaying Batesian mimicry?

Some birds follow moving swarms of army ants in the tropics. As the ants march along the forest floor hunting insects and small vertebrates, birds follow and pick off any insects or small vertebrates that fly or jump out of the way of the ants. This is an example of what kind of species interaction?

Figure 52.1 -In looking at the figure above, what conclusions can be drawn?

Figure 52.3 -In the figure above, which species is the stronger competitor?

Figure 52.4 -Based on the figure above, what result would you expect if you replaced the crabs with broken mussel shells?

Some birds follow moving swarms of army ants in the tropics. As the ants march along the forest floor hunting insects and small vertebrates, birds follow and pick off any insects or small vertebrates that fly or jump out of the way of the ants. What is the specific benefit relationship?

In the hypothesis that C. stellatus a species of barnacle) is competitively excluded from the lower intertidal zone by B. balanoides another species of barnacle) , what could be concluded about the two species?

Which hypothesis supports the observation that herbivores do not generally eat all of the available plants?

Which of the following is not a type of consumption?

Figure 52.2 -What is the term used to describe the process shown in the panels in the figure above?

Refer to the grids below to answer the following question. According to the Shannon Diversity Index, which of the five grids provided, with each one containing 36 square show the greatest diversity?

Figure 52.1 -According to the figure above, which species is more successful in competing for seeds?

What is a likely reason for the observation that there are more species in tropical areas than in places more distant from the equator?

Snails typically avoid sunlit areas, but some snails infected with certain parasites become attracted to light and prefer sunlit areas. Which of the following is the most likely hypothesis given the life cycles of many parasites?

Figure 52.4 -What conclusion can you draw from the figure above?

Figure 52.5 -In the figure above, which of the following statements is true?

Which would be the best way to directly test the hypothesis that C. stellatus a species of barnacle) is competitively excluded from the lower intertidal zone by B. balanoides another species of barnacle) ?