Question 1

Which represents an early stage in primary succession?
A) pine tree growth
B) mosses and lichen on bare rock
C) weedy annual plants in an open field
D) climax species in succession
E) fields of food crops

Accepted Answer

Mosses and lichen growing on bare rock represent an early stage in primary succession because they are the first organisms to inhabit an area and begin the process of breaking down and building up soil.

Question 2

An example of a specific adaptation against predation is ____.
A) photosynthetic dinoflagellates providing sugars to corals
B) eagles and foxes fighting over a carcass
C) two species of Paramecium feeding on bacteria
D) sundew plants and wolf spiders competing for food
E) a skunk squirting foul-smelling, irritating repellents

Accepted Answer

Skunks have developed a specific adaptation against predation by squirting foul-smelling, irritating repellents to deter predators. This is a specific mechanism to protect themselves against predation that is not seen in other organisms listed.

Question 3

The cowbird chick with its foster parent exemplifies an example of ____.
A) commensalism
B) brood parasitism
C) competition
D) mutualism
E) parasitoidism

Accepted Answer

The cowbird chick is an example of brood parasitism, where the cowbird lays its eggs in other bird's nests and lets them raise its young, which is not a mutual relationship, commensalism, competition, or parasitoidism.

Question 4

Many introduced species have deleterious effects on communities and ecosystems because ____.
A) coevolved parasites and pathogens are absent
B) the introduced species are long-lived
C) predators prefer the introduced species, resulting in proliferation of native prey species
D) the community from which they came lost an important predator, competitor, or parasite
E) human beings do not know how to appreciate them

Accepted Answer

Introduced species often lack their natural predators, competitors, or parasites in new environments, which can allow them to proliferate unchecked, often to the detriment of native species and ecosystems.

Question 5

Which is a factor in determining which plant type becomes the pioneer species in a primary succession event?
A) the species of plants that preceded it
B) the animals that occupy the area
C) chance events that affect the order in which pioneer species arrive
D) the nature of the existing soils
E) the type of disturbance

Accepted Answer

Pioneer species in a primary succession event are often determined by chance events that affect the order in which they arrive, as there is no existing soil or ecosystem to influence their establishment initially.

Question 6

The first plant to colonize the plains of Mount Saint Helens after this volcano erupted in 1980 was a prairie lupine. The prairie lupine is therefore an example of ____.
A) a secondary successor
B) a pioneer species
C) a keystone species
D) an exotic species
E) an introduced species

Accepted Answer

The prairie lupine was the first plant to colonize the area after the Mount Saint Helens eruption, making it a pioneer species. A pioneer species is the first organism to inhabit a new environment, and they are important in the process of primary succession.

Question 7

Tapeworms and flukes are examples of ____.
A) commensalism
B) mutualism
C) competition
D) predation
E) parasitism

Accepted Answer

Tapeworms and flukes are both parasitic organisms, which means they live on or inside another organism (the host) and feed on its resources. This relationship benefits the parasite but harms the host, making it an example of parasitism.

Question 8

Two species of closely related squirrels both feed on acorns produced by oak trees. One species feeds exclusively near the top of the tree and the other feeds exclusively toward the bottom of the tree. This is an example of ____.
A) competitive exclusion
B) resource partitioning
C) mutualism
D) commensalism
E) mimicry

Accepted Answer

The fact that the two squirrel species are feeding on the same resource (acorns) but using different parts of the tree (top vs bottom) is an example of resource partitioning, which allows the two species to coexist without directly competing with one another for the same food source. Competitive exclusion would occur if one species outcompetes and eliminates the other from the same niche. Mutualism and commensalism both involve a positive or neutral interaction between two species, but this scenario does not fit either of those categories. Mimicry involves one species evolving to resemble another for protection or other benefits, which is not relevant to this situation.

Question 9

How are parasitoids different from typical brood parasites?
A) T hey are usually not insects.
B) T hey affect only plants.
C) T hey lay eggs inside a host, which is eventually killed.
D) They fool another species into caring for their young.
E) They usually only affect the eggs of birds.

Accepted Answer

Parasitoids lay their eggs inside a host, which is eventually killed as the parasitoid larvae feed on it. This is different from typical brood parasites which lay their eggs in another bird's nest and trick the host bird into caring for their offspring.

Question 10

Considering the traditional view of ecological succession, which plant would most likely be a pioneer species in a primary succession event?
A) an oak tree that produces acorns dispersed by squirrels
B) a snapdragon flower pollinated by bees
C) a dandelion that produces seeds asexually, which are dispersed by the wind
D) a perennial species such as Douglas fir trees
E) a birch tree

Accepted Answer

Pioneer species are typically small, fast-growing plants that can establish themselves in barren environments with little soil or nutrients, such as on bare rock or after a volcanic eruption. Dandelions fit this description as they produce a large number of seeds that can be dispersed over long distances by the wind, allowing them to colonize new areas quickly. Oaks, snapdragons, Douglas firs, and birch trees are all examples of later successional species that require more established soil and nutrient conditions to thrive.

Question 11

Hoverflies 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 hoverflies is enhanced by ____.
A) mimicry
B) display behavior
C) warning coloration
D) chemical defenses
E) camouflage

Accepted Answer

The hoverflies' uncanny resemblance to bees is a form of mimicry. This helps them survive by avoiding predators who might mistake them for bees and avoid attacking them.

Question 12

The plants and animals present in a region from which the trees were removed ten years earlier represent ____.
A) primary succession
B) a climax forest
C) pioneer species
D) secondary succession
E) species introduction

Accepted Answer

The removal of trees ten years earlier suggests that the area had previously been occupied by vegetation, indicating that primary succession did not occur. A climax forest is the stable end-point of succession and requires a long period of undisturbed growth to develop, which cannot happen within ten years of the removal of trees. Pioneer species colonize barren or disturbed land, whereas the presence of plants and animals suggests that the area was not barren. Therefore, the best choice is D: secondary succession, which refers to the process of ecological succession that occurs after an area has been disturbed or damaged, in this case by the removal of trees.

Question 13

Commensalism is a type of ____.
A) predation
B) symbiosis
C) active competition
D) scramble competition
E) competitive exclusion

Accepted Answer

Commensalism is a type of symbiosis where one organism benefits without any effect on the other organism. It is not predation, competition, or competitive exclusion. Scramble competition involves all organisms competing for resources evenly, while active competition involves direct confrontation between organisms.

Question 14

Which is an example of an event that would give rise to primary succession?
A) a dense landslide of mountain rocks covering an entire valley
B) a fire that burns all surface vegetation
C) an abandoned agricultural field
D) a lake that dries up, killing all aquatic plants
E) a forest that is logged

Accepted Answer

Primary succession occurs when an ecological community develops from scratch, with no living things or organic matter present. A landslide of mountain rocks covering an entire valley would create a completely barren landscape, allowing for the development of a new community from scratch. The other options may result in secondary succession, where an ecological community develops from remnants of a previous community.

Question 15

Secondary succession can occur ____.
A) after a fire
B) on a new sand dune
C) on bare rock
D) immediately after the formation of an artificial lake
E) on a glacier

Accepted Answer

Secondary succession occurs in areas where a disturbance has happened but soil is still present, such as after a fire. Choices B, C, D, and E describe scenarios where primary succession would occur, as they involve environments where soil needs to be developed first.

Question 16

This image shows an area in which a glacier has melted. What is indicated by the number "2"? 
A) competition for food resources
B) resource partitioning between two competing species
C) emergence of climax species
D) colonization by pioneer species
E) secondary succession

Accepted Answer

The answer of This image shows an area in which...

Question 17

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) parasitoid
C) commensalist
D) competitive excluder
E) mutualist

Accepted Answer

The phorid fly is a parasitoid, which is an organism that lays eggs inside or on another organism and ultimately kills its host.

Question 18

The monarch butterfly is poisonous to birds; therefore, 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 is an example of mimicry, as the viceroy butterfly has evolved to look like the monarch butterfly in order to avoid predation by birds. The birds recognize the distinct orange and black coloration of the monarch butterfly and avoid eating both monarch and viceroy butterflies due to their similar appearance. Resource partitioning and competitive exclusion both involve direct competition for resources, while camouflage and commensalism are not relevant to this scenario.

Question 19

An example of keystone species are ____.
A) beavers that build dams
B) mice that feed on mushrooms and truffles
C) Douglas fir trees
D) kudzu
E) earthworms that aid decomposition

Accepted Answer

Beavers that build dams create wetland habitats that benefit a variety of organisms, including fish, waterfowl, and insects. Their ecosystem engineering has a significant impact on the distribution and abundance of other species, making them a classic example of a keystone species.

Question 20

This orchid attached to a tree branch is an example of ____. 
A) competition
B) parasitism
C) predation
D) commensalism
E) mutualism

Accepted Answer

The answer of This orchid attached to a tree branch...

Quiz 18: Communities and Ecosystems

Which represents an early stage in primary succession?

An example of a specific adaptation against predation is ____.

The cowbird chick with its foster parent exemplifies an example of ____.

Many introduced species have deleterious effects on communities and ecosystems because ____.

Which is a factor in determining which plant type becomes the pioneer species in a primary succession event?

The first plant to colonize the plains of Mount Saint Helens after this volcano erupted in 1980 was a prairie lupine. The prairie lupine is therefore an example of ____.

Tapeworms and flukes are examples of ____.

Two species of closely related squirrels both feed on acorns produced by oak trees. One species feeds exclusively near the top of the tree and the other feeds exclusively toward the bottom of the tree. This is an example of ____.

How are parasitoids different from typical brood parasites?

Considering the traditional view of ecological succession, which plant would most likely be a pioneer species in a primary succession event?

Hoverflies 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 hoverflies is enhanced by ____.

The plants and animals present in a region from which the trees were removed ten years earlier represent ____.

Commensalism is a type of ____.

Which is an example of an event that would give rise to primary succession?

Secondary succession can occur ____.

This image shows an area in which a glacier has melted. What is indicated by the number "2"?

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 ____.

The monarch butterfly is poisonous to birds; therefore, 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 ____.

An example of keystone species are ____.

This orchid attached to a tree branch is an example of ____.