Question 1

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

Accepted Answer

A pioneer species in primary succession is typically a species that is able to colonize an area with little to no soil and is able to establish itself quickly. Dandelions are able to reproduce asexually, and their seeds can be dispersed by the wind, making them well-suited for this type of environment. Oak trees, snapdragons, and Douglas fir trees all typically require more established soil and environmental conditions to thrive. Birch trees may be able to establish themselves in a secondary succession event, but they are not typically the first species to colonize an area with little to no soil.

Question 2

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

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 3

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 ____.

Accepted Answer

Mimicry enhances the survival of hoverflies because their resemblance to bees, which are often perceived as dangerous due to their ability to sting, deters predators, including humans, from attacking them.

Question 4

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

Accepted Answer

When trees were removed from the region, it caused disturbance to the ecosystem, and a new community developed over time. The plants and animals that established themselves after the disturbance are part of secondary succession. Choice A, primary succession, is the process of the first colonization of a barren habitat, such as a newly formed volcanic island. Choice B, a climax forest, is a stable ecosystem that has reached the end stage of succession. Choice C, pioneer species, are the first species to colonize a bare area in primary succession. Choice E, species introduction, is the deliberate or accidental introduction of non-native species to an ecosystem.

Question 5

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 towards the bottom of the tree. This is an example of ____.

Accepted Answer

The two squirrel species are avoiding direct competition for the same resource (acorns) by partitioning it. One feeds at the top, while the other feeds at the bottom. This is an example of resource partitioning.

Question 6

An example of keystone species are ____.

Accepted Answer

Beavers that build dams are considered a keystone species because their dams create suitable habitats for a variety of other organisms, modify water flow, and increase the availability of nutrients in freshwater ecosystems.

Question 7

Commensalism is a type of ____.

Accepted Answer

Commensalism is a relationship between two species in which one species benefits and the other is neither helped nor harmed. This is a type of symbiotic relationship, where two organisms live in close proximity and have a long-term interaction with each other. The other options are not applicable as predation involves one species killing and eating another, active competition involves two or more species actively competing for the same resources, scramble competition involves all individuals in a population trying to obtain a limited resource and competitive exclusion involves one species outcompeting and eliminating another species.

Question 8

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

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 9

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 ____.

Accepted Answer

The phorid fly is a parasitoid, which is a type of parasite that eventually kills its host. The fly lays its eggs inside the body of the host, and the larvae consume the host's body from the inside out, eventually leading to the host's death.

Question 10

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 ____.

Accepted Answer

This scenario is an example of mimicry, specifically Batesian mimicry. Viceroy butterflies have evolved to look like monarch butterflies, even though they are not poisonous themselves. This helps them avoid being eaten by birds, who have learned to associate the monarch butterfly's coloration with toxicity.

Question 11

How are parasitoids different from typical brood parasites?

Accepted Answer

Unlike typical brood parasites, parasitoids lay their eggs inside a host, which is eventually killed as the parasitoid larvae feed on the host's body tissues, ultimately resulting in the death of the host.

Question 12

An example of a specific adaptation against predation is ____.

Accepted Answer

Skunks have evolved the ability to secrete a foul-smelling, irritating repellent as a defense against predation. This adaptation makes them less attractive to predators and increases their chances of survival.

Question 13

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

Accepted Answer

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

Question 14

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

Accepted Answer

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

Question 15

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 ____.

Accepted Answer

A pioneer species is the first type of organism to colonize an area after a disturbance, such as a volcanic eruption. The prairie lupine being the first plant to colonize the plains of Mount Saint Helens after the eruption makes it a pioneer species.

Question 16

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

Accepted Answer

Primary succession occurs when there is a complete absence of vegetation and soil, and a bare rock surface is exposed. A landslide of mountain rocks covering an entire valley would provide a similar condition for primary succession to take place.

Question 17

Which represents an early stage in primary succession?

Accepted Answer

Mosses and lichen growing on bare rock represent an early stage in primary succession. These organisms are the pioneer species that colonize a barren environment and gradually begin to create soil and organic matter, paving the way for larger plants to grow.

Question 18

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

Accepted Answer

The cowbird chick is an example of brood parasitism, where a bird lays its eggs in the nest of another bird species and lets the host parent raise its offspring. This is a form of parasitism because the cowbird chick benefits at the expense of the host parent, which may have to allocate more resources to the larger cowbird chick than its own offspring.

Question 19

Secondary succession can occur ____.

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 20

Tapeworms and flukes are examples of ____.

Accepted Answer

Tapeworms and flukes are parasitic organisms that benefit at the expense of their host. They harm their host by taking nutrients and energy they need for survival.

Quiz 17: Communities and Ecosystems