Question 1

Phorid flies lay their eggs inside the bodies of various insects and spiders.When the larvae hatch they consume the body of the 'host' from the inside out.The phorid fly is an example of
A) a brood parasite.
B) a parasitoid.
C) a commensalist.
D) a competitive excluder.
E) more than one of these.

Accepted Answer

Phorid flies are parasitoids because they lay their eggs inside the bodies of other insects or spiders, which ultimately leads to the death of the host. As the larvae hatch, they consume and kill the host from the inside out. This is different from brood parasites, which lay their eggs in the nests of other species to be raised by the host, commensalism, which is a non-harmful relationship, and competitive exclusion, where one species outcompetes another for resources.

Question 2

A relationship between two species in which both species benefit is known as
A) parasitism.
B) mutualism
C) competition.
D) predation.
E) commensalism.

Accepted Answer

Mutualism is the relationship between two species in which both species benefit. This is different from parasitism, in which one species benefits and the other is harmed, or competition, in which both species are harmed. It is also different from commensalism, in which one species benefits and the other is neutral.

Question 3

Competitive exclusion is based upon the idea that
A) one species will voluntarily allow the other to survive.
B) no two species can completely occupy the same niche.
C) the larger species will dominate the smaller.
D) competition is overrated as a factor in species survival.
E) two species can live together, if they share the same niche but only at alternate times.

Accepted Answer

Competitive exclusion is based on the idea that no two species can completely occupy the same niche, as competition for resources will ultimately lead to the exclusion of one species by the other. This is also known as the "competitive exclusion principle."

Question 4

Hover flies like to drop in at outdoor picnics to sample the sweets,but the reaction of humans is to flee the scene because of the flies' uncanny resemblance to bees.Thus the survival of Hover flies is enhanced by
A) mimicry.
B) display behavior.
C) warning coloration.
D) chemical defenses.
E) camouflage.

Accepted Answer

Hover flies benefit from mimicry as it allows them to avoid predators such as humans who mistake them for bees. Mimicry is a form of adaptation where one species resembles another species in order to gain an advantage, such as protection from predators. It is a common survival strategy in nature. Display behavior, warning coloration, chemical defenses, and camouflage are also survival strategies used by animals, but in this particular scenario, mimicry is the best choice as it directly applies to the hover flies' survival in the presence of humans at picnics.

Question 5

A hummingbird that pollinates morning glory flowers and nests in the crotch of an apple tree.The apple tree is not harmed or helped by the hummingbird.The relationship between the hummingbird and the apple tree is a
A) mutualism.
B) commensalism.
C) competition.
D) parasitism.
E) predation.

Accepted Answer

This is an example of commensalism as the hummingbird benefits from the flowers of the morning glory and the apple tree offers a nesting site for the hummingbird, but the apple tree is not affected positively or negatively by the presence of the hummingbird.

Question 6

The monarch butterfly is poisonous to birds and so birds avoid eating them.Viceroy butterflies look very similar to monarch butterflies but are not poisonous.Because they look like monarch butterflies,birds also do not eat viceroy butterflies.This is an example of
A) resource partitioning.
B) competitive exclusion.
C) mimicry.
D) camouflage.
E) commensalism.

Accepted Answer

This phenomenon is an example of mimicry. Viceroy butterflies have evolved to look like monarch butterflies to fool birds into thinking they are also poisonous, thus avoiding being eaten. This is a strategy used by prey to reduce their chances of being eaten by predators. Resource partitioning refers to the division of limited resources between different species to reduce competition, while competitive exclusion refers to one species outcompeting another for resources. Camouflage involves blending in with the environment, and commensalism refers to a relationship where one species benefits and the other is neither harmed nor helped.

Question 7

The subdividing of some category of similar resources in a way that allows competing species to exist is
A) competitive exclusion.
B) social parasitism.
C) predation.
D) mimicry.
E) resource partitioning.

Accepted Answer

Resource partitioning is the process of dividing a category of similar resources into smaller subdivisions to allow competing species to coexist. This reduces competition and allows each species to utilize slightly different resources or occupy a different niche within the same ecosystem.

Question 8

Which of the following is true of predation?
A) A predator exerts selective pressure on its prey.
B) A prey exerts selective pressure on its predator.
C) In a typical predation case, the predator would not kill its prey.
D) Feeding on carcasses is also an example of predation.
E) Predator and prey exert selective pressure on one another.

Accepted Answer

The answer of Which of the following is true of...

Question 9

How are parasitoids different than parasites?
A) they are usually not insects
B) they affect only plants
C) the host is killed
D) they have no lasting effect on their hosts
E) they usually only affect the eggs of birds

Accepted Answer

Parasitoids differ from parasites in that they ultimately kill their host. Parasites, on the other hand, usually live in or on their host for an extended period of time, but do not typically kill it.

Question 10

Which of the following is NOT characteristic of parasites?
A) They are specialists and usually are able to affect only one variety of hosts.
B) They inflict serious injury and kill their hosts.
C) Some reside inside their hosts, whereas others live outside their hosts.
D) Their host may be a plant as well as an animal.
E) They are dependent on hosts.

Accepted Answer

Parasites typically do not kill their hosts but rely on them for survival. Killing their host means the loss of their own habitat, food source, and reproductive environment. Many parasites have evolved mechanisms to ensure their host's longevity, so they can continue to thrive inside or on their hosts without disrupting their normal physiology or behavior. Therefore, inflicting serious injury or killing their hosts is not a typical characteristic of parasites.

Question 11

The mycorrhizal relationship you studied in a previous chapter is an example of
A) commensalism.
B) mutualism.
C) competition.
D) predation.
E) parasitism.

Accepted Answer

The mycorrhizal relationship between fungi and plant roots is an example of mutualism, where both species benefit from the interaction. The fungi provide the plant with nutrients, particularly phosphorus, in exchange for carbon compounds from the plant.

Question 12

A sheep eating by pulling the plant out of the ground is an example of
A) parasitism.
B) predation.
C) commensalism.
D) mutualism.
E) competitive exclusion.

Accepted Answer

Predation involves one organism (the predator) killing and consuming another organism (the prey). In this scenario, the sheep is consuming the plant by pulling it out of the ground, therefore it is an example of predation. Parasitism involves one organism benefiting at the expense of another organism, commensalism involves one organism benefiting while the other is neither helped nor harmed, mutualism involves two organisms benefiting from each other, and competitive exclusion involves two species competing for the same resources and one species being excluded from the ecosystem.

Question 13

Resource partitioning is the result of
A) parasitism.
B) mutualism.
C) competition.
D) predation.
E) commensalism.

Accepted Answer

Resource partitioning is a phenomenon where species with similar ecological requirements compete for the same limited resources. To avoid competition, species divide and specialize in their use of resources. This results in a partitioning of resources between different species, which reduces competition and allows for coexistence. Therefore, resource partitioning is a result of competition.

Question 14

The relationship between the yucca plant and the yucca moth that pollinates it is best described as
A) commensalism.
B) parasitism.
C) predation.
D) mutualism.
E) all of these.

Accepted Answer

The relationship between the yucca plant and yucca moth is mutualism, as both species have evolved to depend on each other for reproduction. The yucca plant provides a place for the yucca moth to lay its eggs, and in return, the yucca moth pollinates the plant. Neither species would survive without the other in this relationship.

Question 15

The interaction in which one species benefits and the second species is neither harmed nor benefited is
A) mutualism.
B) parasitism.
C) commensalism.
D) competition.
E) predation.

Accepted Answer

Commensalism describes a relationship in which one species benefits while the other is neither harmed nor helped. This differs from mutualism, in which both species benefit, parasitism, in which one species benefits while the other is harmed, competition, in which both species are harmed, and predation, in which one species benefits while the other is harmed.

Question 16

The interaction between two species in which both species may be harmed is known as
A) parasitism.
B) mutualism.
C) competition.
D) predation.
E) commensalism.

Accepted Answer

In competition, both species are vying for the same resources and may suffer negative consequences as a result. In parasitism, one species benefits while the other is harmed. In mutualism, both species benefit. In predation, one species is a predator and benefits while the other is preyed upon and is harmed. In commensalism, one species benefits while the other is neither benefited nor harmed.

Question 17

Populations are held in check by
A) resource partition.
B) predation.
C) social parasitism.
D) competition.
E) all of these.

Accepted Answer

All of these factors can contribute to regulating populations. Resource partitioning may limit the amount of resources available to a particular species, which can in turn limit their population size. Predation can directly reduce population numbers, as can social parasitism. Competition can result in decreased reproductive success or survival for individuals in a population, which can also limit overall population size.

Question 18

In contrast to predation,a parasite usually
A) does not kill the animal on which, or in which, it lives.
B) kills its host.
C) is a short-term visitor.
D) is larger than its host.
E) does not kill the animal on which, or in which, it lives and is larger than its host.

Accepted Answer

A parasite usually does not kill the animal on which, or in which, it lives. Instead, it feeds on the host's nutrients and can cause harm over a longer period of time, but not to the point of killing the host.

Question 19

The bacterium,E.coli,lives in the large intestines of mammals and feeds on undigested food material.E.coli helps to synthesize vitamin K that is essential for mammalian blood clotting.The relationship between E.coli and mammals is a
A) commensalism.
B) mutualism.
C) competition.
D) predation.
E) parasitism.

Accepted Answer

The relationship between E.coli and mammals is mutualistic because E.coli lives in the large intestines of mammals and feeds on undigested food material, and in return, it helps to synthesize vitamin K, which is essential for mammalian blood clotting. Therefore, both E.coli and mammals benefit from this relationship.

Question 20

Which of the following is an adaptation against predation?
A) thorns
B) camouflage
C) mimicry
D) tough, chewy leaves
E) all of these

Accepted Answer

All of the options listed are examples of adaptations against predation. Thorns deter herbivores and also make it difficult for some predators to approach a plant. Camouflage helps prey avoid detection by predators. Mimicry allows prey to resemble harmful or unpalatable species, deterring predators. Tough, chewy leaves may be difficult for some herbivores to eat, reducing the likelihood that they will be consumed.

Quiz 17: Communities and Ecosystems

Phorid flies lay their eggs inside the bodies of various insects and spiders.When the larvae hatch they consume the body of the 'host' from the inside out.The phorid fly is an example of

A relationship between two species in which both species benefit is known as

Competitive exclusion is based upon the idea that

Hover flies like to drop in at outdoor picnics to sample the sweets,but the reaction of humans is to flee the scene because of the flies' uncanny resemblance to bees.Thus the survival of Hover flies is enhanced by

A hummingbird that pollinates morning glory flowers and nests in the crotch of an apple tree.The apple tree is not harmed or helped by the hummingbird.The relationship between the hummingbird and the apple tree is a

The monarch butterfly is poisonous to birds and so birds avoid eating them.Viceroy butterflies look very similar to monarch butterflies but are not poisonous.Because they look like monarch butterflies,birds also do not eat viceroy butterflies.This is an example of

The subdividing of some category of similar resources in a way that allows competing species to exist is

Which of the following is true of predation?

How are parasitoids different than parasites?

Which of the following is NOT characteristic of parasites?

The mycorrhizal relationship you studied in a previous chapter is an example of

A sheep eating by pulling the plant out of the ground is an example of

Resource partitioning is the result of

The relationship between the yucca plant and the yucca moth that pollinates it is best described as

The interaction in which one species benefits and the second species is neither harmed nor benefited is

The interaction between two species in which both species may be harmed is known as

Populations are held in check by

In contrast to predation,a parasite usually

The bacterium,E.coli,lives in the large intestines of mammals and feeds on undigested food material.E.coli helps to synthesize vitamin K that is essential for mammalian blood clotting.The relationship between E.coli and mammals is a

Which of the following is an adaptation against predation?