Question 1

Which of the following statements about competition is FALSE?
A) It can limit the distribution of a species.
B) It can limit the abundance of a species.
C) It can increase the differences between species.
D) It can make two species become more alike.

Accepted Answer

Competition typically drives species to adapt and evolve in ways that increase their differences from potential competitors. This can lead to niche specialization and coexistence. Thus, competition generally does not make two species become more alike.

Question 2

Which of the following is most likely to be an example of an induced response?
A) bright colors on the wings of a toxic butterfly
B) spines on a cactus habitually exposed to grazing
C) brightly colored flowers on a rosebush
D) color patterns on a poisonous snake

Accepted Answer

The spines on a cactus are induced by habitual exposure to grazing, meaning the cactus developed this response in response to a specific environmental factor. The other options are examples of adaptations that may have evolved over time but are not necessarily induced responses.

Question 3

A praying mantis captures and devours many insects during its lifetime;the relationship between a mantis and the exploited species (for example,a grasshopper)is one of
A) parasite/host.
B) pathogen/prey.
C) parasite/prey.
D) predator/prey.

Accepted Answer

The relationship between a praying mantis and the insects it preys upon is that of predator/prey. This is because the mantis actively hunts and captures its prey, consuming it for food, while the prey is the hunted and consumed organism in this interaction. The other choices (parasite/host, pathogen/prey, parasite/prey) do not accurately describe the relationship between a mantis and its prey.

Question 4

In the centers of their ranges,two species of hummingbirds have very similar tongue lengths,but where the ranges overlap,one species has a shorter tongue and the other a longer tongue.This would most likely be an example of
A) seed-dispersal mutualism.
B) parasitism.
C) character displacement.
D) a predator-prey interaction.

Accepted Answer

Character displacement refers to the phenomenon where species evolve to become more different from each other when they coexist in the same geographic area. In this case, the two species of hummingbirds have similar tongue lengths in their respective ranges, but when they overlap, one species has a shorter tongue and the other has a longer tongue. This suggests that they have evolved to occupy slightly different niches, reducing competition between them.

Question 5

Which of the following patterns represents the outcomes of a commensalistic relationship?
A) +/-
B) +/+
C) o/+
D) -/-

Accepted Answer

The pattern o/+ indicates a commensalistic relationship, where one species benefits (+) and the other is neither helped nor harmed (o).

Question 6

Which of the following statements is FALSE?
A) The level of predation can be so intense that the prey can be driven to extinction.
B) Predation can stimulate the reproductive capacity of a prey species and can cause the abundance of that prey to increase.
C) The selective pressure caused by predation can alter the behavior of its prey.
D) The distribution of a predatory species can restrict the distribution of its prey.

Accepted Answer

Predation can cause a decrease in abundance of a prey species, and although it may stimulate changes in behavior, it does not necessarily lead to an increase in reproductive capacity.

Question 7

Examine the following graph;what best describes the cycling that each population experiences?

A) Lynx populations decrease in size when hare populations increase in size;hares are the superior competitors.
B) Lynx populations increase in size when hare populations decrease in size;lynx are the superior competitors.
C) Lynx populations decrease in size when hare populations decrease in size;lynx are exploiting the hare population.
D) The increase and decrease of each species is driven by oscillating density-independent factors,but since they share the same habitat,the cycles coincide.

Accepted Answer

The graph shows a classic example of predator-prey interactions between lynx and hares, where the lynx population increases in size as hare populations decrease and vice versa. This suggests that lynx are the superior competitors and regulate hare populations through predation.

Question 8

Which of the following patterns represents a competitive interaction?
A) +/-
B) +/+
C) o/+
D) -/-

Accepted Answer

The pattern that represents a competitive interaction is -/-, which means both organisms are negatively impacted or harmed by the presence of the other. This describes competition, where two or more organisms are using the same limited resources, resulting in a decrease in resources available to both.

Question 9

Which of the following patterns represents the outcome of a parasitic relationship?
A) +/-
B) +/+
C) o/+
D) -/-

Accepted Answer

The answer of Which of the following patterns represents the...

Question 10

When two similar species inhabit the same area,they may evolve over time to become more different and
A) drive the other species to extinction.
B) reduce direct competition.
C) use up the other species' resources.
D) reduce their genetic variation.

Accepted Answer

When similar species inhabit the same area, they often compete for resources such as food, water, and habitat. Over time, natural selection may favor traits that allow each species to specialize in different aspects of resource use, reducing the amount of direct competition between them. This can lead to the evolution of more distinct differences between the two species. The other options (drive the other species to extinction, use up the other species' resources, and reduce their genetic variation) may occur in some situations, but are not the most likely outcome when similar species coexist.

Question 11

Herbivores interact exploitatively with the plants they consume;do they simultaneously participate in any other relationships within their communities?
A) Yes: an herbivore will have mutualistic relationships with intestinal bacteria and an exploitative relationship with its predators.
B) No: community relationships always have costs,so reducing them increases an organism's fitness.
C) No: only a single type of interaction can occur at a time,although herbivores can participate in several exploitative relationships at once.
D) Yes: each of the plant species eaten needs to be considered a separate interaction.

Accepted Answer

Herbivores can have mutualistic relationships with the bacteria in their intestines, which aid in the digestion of plant material. They also have exploitative relationships with predators that may prey on them. Therefore, herbivores can participate in multiple types of interactions within their communities.

Question 12

Some species of warblers partition their niche by foraging in different parts of the same tree,although all birds eat the same species of insects and spiders.What mechanism has natural selection used to produce this interaction?
A) character displacement
B) behavioral modification
C) directional selection
D) competitive exclusion

Accepted Answer

The answer of Some species of warblers partition their niche...

Question 13

Female ducks frequently deposit fertile eggs in the nests of unattended neighboring ducks.These eggs hatch and are then reared by the foster parent.What term best describes this behavior?
A) parasitism
B) behavioral mutualism
C) exploitative competition
D) nest mutualism

Accepted Answer

This behavior is known as parasitism because the female duck benefits by having her offspring raised by another, while the foster parent incurs the cost of raising offspring that are not genetically related to them, without receiving any direct benefits.

Question 14

Flies belonging to the family Phoridae inject their eggs into fire ants.The larva that subsequently hatches feeds on the ant until it pupates.The larva would be best described as a
A) parasite.
B) gut mutualist.
C) predator.
D) pathogen.

Accepted Answer

The larva of the fly belonging to the family Phoridae injects its eggs into the fire ants and feeds on the ant until it pupates. This relationship is parasitic because the larva benefits from the ant's resources while harming the ant.

Question 15

Parasites,and the disease they cause,represent a distinctive type of exploitation because
A) of the high mortality rates associated with infection.
B) parasites affect only specific portions of the host.
C) of the chronic and progressive debilitation of the host.
D) parasites represent the only species interaction where the symbiont lives on or in the host organism.

Accepted Answer

Parasites cause chronic and progressive debilitation of the host, which is a unique and distinctive type of exploitation. While high mortality rates are certainly a concern with parasitic infections, they are not necessarily the defining characteristic. Similarly, parasites may or may not affect specific portions of the host, and while they are one example of symbiotic relationships, they are not the only one.

Question 16

In ________ competition,species compete indirectly for a shared resource,each reducing the amount available to the other competitor.
A) exploitative
B) restrictive
C) interference
D) advantageous

Accepted Answer

Exploitative competition occurs when species compete indirectly by consuming a shared resource, each reducing the amount available to the others.

Question 17

By growing on the trunk or branch of a tree,a lichen gains height and exposure to sunlight for photosynthesis.The tree is not harmed by the lichen but does not benefit either.The relationship between the lichen and the tree is
A) commensalism.
B) mutualism.
C) parasitism.
D) interference competition.

Accepted Answer

The relationship between the lichen and the tree is commensalism, where the lichen benefits by using the tree as a substrate to grow and gain exposure to sunlight, while the tree is not harmed nor benefited by the presence of the lichen.

Question 18

Cowbirds lay their eggs in the nests of smaller birds.The fast-developing cowbird chicks hatch first,and push the other baby chicks out of the nest as they hatch.Which interaction best describes cowbird behavior?
A) mutualism
B) parasitism
C) predation
D) exploitative competition

Accepted Answer

Cowbirds lay their eggs in the nests of smaller birds, which harms the host bird by forcing it to raise the larger cowbird chick instead of its own offspring. This is an example of parasitism, where one species benefits at the expense of another.

Question 19

What statement summarizes the outcomes of a parasitic relationship?
A) Both the parasite and the host benefit.
B) Only the parasite benefits;the host is harmed.
C) Only the host benefits;the parasite is harmed.
D) Both the parasite and the host are harmed.

Accepted Answer

In a parasitic relationship, the parasite benefits by deriving nutrients or resources from the host, while the host is harmed by the relationship. Therefore, only the parasite benefits, and the host is harmed.

Question 20

The release of a parasitic wasp in California helped control the infestation of scale insects on citrus trees.However,it also caused the near extinction of a different species of parasitic wasp.Should we consider this experiment an unqualified success?
A) Yes;the scale insects are controlled,and the extinct wasp was not ecologically important.
B) Yes;as long as we get a result that helps humans,it does not matter what the effect is on other species.
C) No;the effect of the loss of the original species of wasp cannot be predicted and may be more significant than the benefits to the citrus tree crop.
D) No;the citrus tree population in California will now be able to rise to unmanageable numbers.

Accepted Answer

The loss of any species in an ecosystem can have unpredictable and potentially significant effects. While the control of scale insects on citrus trees is beneficial, it is important to weigh the potential consequences on other species before declaring the experiment a success.

Quiz 23: Ecological Communities

Which of the following statements about competition is FALSE?

Which of the following is most likely to be an example of an induced response?

A praying mantis captures and devours many insects during its lifetime;the relationship between a mantis and the exploited species (for example,a grasshopper) is one of

In the centers of their ranges,two species of hummingbirds have very similar tongue lengths,but where the ranges overlap,one species has a shorter tongue and the other a longer tongue.This would most likely be an example of

Which of the following patterns represents the outcomes of a commensalistic relationship?

Which of the following statements is FALSE?

Examine the following graph;what best describes the cycling that each population experiences?

Which of the following patterns represents a competitive interaction?

Which of the following patterns represents the outcome of a parasitic relationship?

When two similar species inhabit the same area,they may evolve over time to become more different and

Herbivores interact exploitatively with the plants they consume;do they simultaneously participate in any other relationships within their communities?

Some species of warblers partition their niche by foraging in different parts of the same tree,although all birds eat the same species of insects and spiders.What mechanism has natural selection used to produce this interaction?

Female ducks frequently deposit fertile eggs in the nests of unattended neighboring ducks.These eggs hatch and are then reared by the foster parent.What term best describes this behavior?

Flies belonging to the family Phoridae inject their eggs into fire ants.The larva that subsequently hatches feeds on the ant until it pupates.The larva would be best described as a

Parasites,and the disease they cause,represent a distinctive type of exploitation because

In ________ competition,species compete indirectly for a shared resource,each reducing the amount available to the other competitor.

By growing on the trunk or branch of a tree,a lichen gains height and exposure to sunlight for photosynthesis.The tree is not harmed by the lichen but does not benefit either.The relationship between the lichen and the tree is

Cowbirds lay their eggs in the nests of smaller birds.The fast-developing cowbird chicks hatch first,and push the other baby chicks out of the nest as they hatch.Which interaction best describes cowbird behavior?

What statement summarizes the outcomes of a parasitic relationship?

The release of a parasitic wasp in California helped control the infestation of scale insects on citrus trees.However,it also caused the near extinction of a different species of parasitic wasp.Should we consider this experiment an unqualified success?