Question 1

Ballast water from ships has been responsible for the intercontinental spread of a number of invasive species.One promising strategy proposed by conservationists to reduce this danger is to

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Question 2

The rate of extinctions that occurred normally throughout history, when mass extinction events were not occurring, is called the _______.

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Question 3

In some parts of the Midwest, prairie restoration programs have required replacement of introduced agricultural grasses, such as bluegrasses, with the native prairie grasses that once thrived there.Prairie restoration proved difficult until scientists discovered that native prairie grasses were adapted to survive periodic wildfires, while introduced grasses were not.They changed their method to include prescribed burns.In this case, the restoration ecology project benefited from the use of which ecological concept?

Accepted Answer

The use of periodic disturbances, such as prescribed burns, is a key concept in restoration ecology. In this case, the periodic wildfires that native prairie grasses evolved to withstand were recreated through prescribed burns, which allowed the native grasses to thrive and replaced the previously introduced agricultural grasses.

Question 4

The use of CITES to protect an endangered species would be most appropriate under circumstances in which a species is threatened by

Accepted Answer

CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) is an international treaty that aims to ensure that international trade in certain species of plants and animals does not threaten their survival in the wild. Therefore, the use of CITES would be most appropriate when a species is threatened by illegal poaching and killing for a product, such as ivory or rhino horns. CITES can help regulate international trade of these products, and provide protection for the endangered species.

Question 5

Michigan scientists are trying to save the endangered Kirtland's warbler, a small songbird that breeds only in even-aged stands of jack pine.They have replanted stands of jack pine and used prescribed burning to develop stands of the middle-aged trees the warblers prefer.Which ecological concept is being used to aid this restoration ecology project?

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Question 6

Human-caused changes such as habitat loss, overharvesting, and climate change often lead to lowered effective population sizes, which in turn lead to a loss of ecosystem _______.

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Question 7

What major factor prevents the use of captive breeding programs as a solution for saving endangered species?

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Question 8

A species of bird is critically endangered, and its habitat is rapidly disappearing.A conservationist committed to preventing the extinction of this species would be most likely to undertake which type of program in the short term?

Accepted Answer

A captive breeding program would buy time for the bird species while its habitat is being restored. This would increase the number of individuals in the population and reduce the risk of extinction. The other options may be beneficial in the long-term but may not have an immediate impact on the survival of the species in the short-term.

Question 9

When populations become smaller and lack genetic diversity, they are more likely to become _______.

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Question 10

Up to 90 percent of saltwater fish caught for the aquarium trade are captured by dousing coral reefs with sodium cyanide.Many fish die, but those that receive only low doses are temporarily incapacitated, so they are easily captured.The coral reef, which cannot swim away, receives most of the cyanide.Many corals and other reef animals die, and the cyanide effects ripple through the food web.This information suggests that cyanide is hazardous to

Accepted Answer

The use of cyanide affects not only the targeted fish but also the entire coral reef community. Many corals and other reef animals die, and the cyanide effects ripple through the food web. Therefore, option A is the best answer.

Question 11

Most wildlife trade is legal.It includes trade in both plants and animals; thus, exotic flowers, pets, wood used for furniture, and "wild" ingredients used in food and medicines are all included.Conservationists consider wildlife trade a problem when it is illegal and involves endangered species.This is most likely because endangered species

Accepted Answer

Endangered species have low breeding populations, and illegal trade can easily deplete their numbers to the point of extinction. This is why conservationists consider wildlife trade a problem when it involves endangered species.

Question 12

Assume a potentially invasive species is about to be accidentally introduced into the United States via ship ballast water.The best way to control this species is to

Accepted Answer

The best option is to prevent the introduction of the potentially invasive species by treating ballast water before it is released. This approach is more effective and efficient than trying to eradicate a well-established population, which can be very costly and unlikely to succeed. Passing a law to ban accidental introduction is also a good idea, but it may not be as feasible as treating ballast water. preventing the movement of the ship would also be effective but can cause significant economic losses.

Question 13

According to the categories set by the International Union for Conservation of Nature (IUCN), the species most highly threatened by extinction are classified as _______.

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The answer of According to the categories set by the...

Question 14

One way ecologists try to estimate the effect of habitat loss on the rate of extinctions is by applying a concept from island biogeography known as the _______ relationship.

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The answer of One way ecologists try to estimate the...

Question 15

Conservationists undertaking a restoration ecology project would most likely be seeking which outcome?

Accepted Answer

Conservationists involved in restoration ecology aim to speed up the natural process of ecosystem restoration, helping to return a damaged or destroyed ecosystem back to its original state more quickly than it would through natural processes alone.

Question 16

A landowner wants to control an invasive plant species.He analyzes the spread of the plant and realizes that the plant infestation has three areas: a highly infested core area, a middle area or "advancing front" that has fewer plants but is expanding, and an outlier area that has the lowest plant density.The landowner decides to focus his first control efforts on the outlier area.What is his likely rationale for this choice?

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Question 17

Genetic drift, leading to inbreeding depression, combined with demographic stochasticity can threaten biodiversity because it results in a smaller _______.

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Question 18

Which action is the best example of restoration ecology?

Accepted Answer

Restoration ecology involves returning damaged ecosystems back to their natural state. Converting an agricultural area into an industrial area (A) and adding windmills to a pastureland (E) do not involve restoring damaged ecosystems. Leaving an abandoned industrial site to return to nature on its own (C) is passive restoration, but active restoration involves human intervention. Planting new trees and shrubs on a suburban lawn (D) may be a form of landscaping but it does not involve restoring a damaged ecosystem. Therefore, the best example of restoration ecology is returning an agricultural area back to its natural wetland state (B).

Question 19

Each country that participates in CITES issues a permit for the sale of all legal wildlife or plant species.Species listed by CITES are not permitted.At trade sites, merchandise is counted and checked to ensure its legality.In this way, the CITES agreement helps limit illegal trade in endangered species.What recent factor in elephant conservation has made enforcement of the CITES agreement less useful?

Accepted Answer

The recent factor in elephant conservation that has made enforcement of the CITES agreement less useful is that legal or sanctioned ivory is now mixed with poached ivory and cannot be distinguished. This makes it difficult for authorities to determine the legality of ivory trade, which undermines the effectiveness of CITES in limiting illegal trade in endangered species.

Question 20

Since 1980, the world population of leatherback turtles has dropped by 63-77 percent.This decline has resulted from poaching for eggs and meat, destruction of nesting sites, accidental catches by fishermen, disorientation of nestlings due to artificial lighting from coastal developments, and more.This suggests that the decline in the leatherback turtle population is almost entirely due to _______, not natural, causes.

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The answer of Since 1980, the world population of leatherback...

Quiz 58: A Changing Biosphere