Question 1

The world's wild species provide ecological resources and services that keep us alive and support human economies.

Accepted Answer

The world's wild species play important roles in supporting ecosystems and providing resources that humans depend on, such as clean air and water, food, and medicine. Without these ecological services, human economies and societies would not be sustainable.

Question 2

Human population growth is one of the causes of extinction.

Accepted Answer

As human population grows, we require more resources, which leads to the destruction of habitats and the loss of biodiversity. This, in turn, can lead to the extinction of certain species. Additionally, human activities such as hunting, fishing, and pollution can also contribute to species extinction.

Question 3

The United States Endangered Species Act offers protection only for species located within United States boundaries.

Accepted Answer

The United States Endangered Species Act can offer protections for species located both within and outside of the United States boundaries, as it aims to protect species that are considered endangered or threatened regardless of their geographic location.

Question 4

If human activities allow an invasive species to thrive, its speciation and population growth rates may be higher at the same time that it depresses speciation and growth rates of other species.

Accepted Answer

This statement is true. Invasive species can outcompete native species, consume their resources, and disrupt their natural ecosystems, leading to a decline in their population and speciation rates. However, invasive species may also have advantageous traits that allow them to quickly adapt to and thrive in their new environment, leading to higher speciation and population growth rates for the invasive species.

Question 5

When introduced to a new area, nonnative species always thrive because their predators are not present.

Accepted Answer

Nonnative species do not always thrive in new areas; their success can depend on various factors such as climate, availability of resources, competition with native species, and indeed, the presence or absence of predators or diseases.

Question 6

Red fire ants have developed a genetic resistance to pesticides.

Accepted Answer

Research has shown that some red fire ants have developed a genetic resistance to certain pesticides, making it more difficult to control infestations.

Question 7

Aquariums have been effectively used as gene banks for large marine mammals.

Accepted Answer

While aquariums can serve as places of education and conservation, they do not function as gene banks for large marine mammals. Gene banks typically involve storing samples of DNA, eggs, and sperm from individuals to preserve genetic diversity and potentially use in breeding programs. Aquariums do not typically have the capacity or resources to serve this function.

Question 8

The primary reason that polar bear populations are declining is because the higher temperatures resulting from climate change cause them to overheat due to their thick fur.

Accepted Answer

The primary reason for declining polar bear populations is not overheating due to thick fur but rather the loss of sea ice, which is essential for hunting their primary prey, ringed seals. Climate change is causing the Arctic sea ice to melt earlier in the spring and form later in the fall, reducing the amount of time that polar bears have to hunt and store up fat reserves for the winter. Additionally, some populations are experiencing food shortages and increased competition for resources as a result of climate change.

Question 9

Although many species are useful for humans, introduced exotic species are almost never useful.

Accepted Answer

While introduced exotic species can cause negative impacts on ecosystems, there are some cases where they may be useful to humans. For example, some invasive plant species have been utilized for medicinal purposes. However, the overall impact of introduced exotic species is typically negative.

Question 10

Roads do not cause habitat fragmentation.

Accepted Answer

Roads can contribute to habitat fragmentation by creating barriers that can prevent or limit the movement of wildlife and their access to resources, such as food and mates. This can lead to isolated populations and a loss of genetic diversity. Additionally, roads can increase mortality rates for animals that attempt to cross them, either through direct collisions with vehicles or through barriers such as noise and light pollution that can affect their behavior and survival.

Question 11

Pollution from human activities has only minor effects on the environment, so the primary concern when pollution occurs is that it affects human health.

Accepted Answer

Pollution from human activities has major effects on the environment such as air pollution, water pollution, and soil contamination which can harm aquatic and terrestrial ecosystems, wildlife, and also cause climate change. Human health is certainly a concern, but it is not the only concern when it comes to pollution.

Question 12

It is estimated that between 20% and 50% of the world's plant and animal species will suffer premature extinction by the end of this century.

Accepted Answer

This is a widely accepted estimate based on current rates of habitat loss, climate change, pollution, and other factors that threaten biodiversity.

Question 13

The African honeybee, also known as the killer bee, is a deliberately introduced invasive species.

Accepted Answer

The African honeybee (Apis mellifera scutellata) was intentionally introduced to South America in the 1950s in an attempt to improve honey production. However, some bees escaped and spread throughout the continent, eventually reaching North America. They are considered an invasive species due to their aggressive behavior and ability to outcompete native bee populations.

Question 14

A male lion in Kenya generates more money through ecotourism than if killed for its skin.

Accepted Answer

Ecotourism is a major source of income for many countries, and Kenya is no exception. Tourists come from all over the world to see and photograph the majestic lions of Africa, and the country earns millions of dollars each year from this industry. Killing a lion for its skin, on the other hand, would only generate a one-time profit and would not contribute to the long-term sustainability of the tourism industry. Therefore, it is more economically beneficial to protect and conserve these animals for ecotourism purposes.

Question 15

A particular species of endangered bird distributes seeds for plants and is an important food for other animals, so it may be considered a keystone species and especially important to target for conservation efforts.

Accepted Answer

A keystone species is one whose impact on its ecosystem is proportionally greater than its abundance would suggest, and if its presence were to be removed, the ecosystem would be dramatically changed. Based on the given information, the particular species of endangered bird seems to play a crucial role in the ecosystem, making it a keystone species and therefore important to target for conservation efforts.

Question 16

Species can be more vulnerable to storms and forest fires because of habitat fragmentation.

Accepted Answer

Habitat fragmentation can cause isolated populations of species that are more vulnerable to natural disasters like storms and forest fires. The limited habitat and reduced genetic diversity can make it difficult for these populations to recover after a catastrophic event.

Question 17

A species is discovered in a remote area of Hawaii during a new building project. This species is especially likely to be at risk of extinction due to this type of habitat change just because it is an island species.

Accepted Answer

Island species are often more vulnerable to habitat changes and human activities because they have evolved in isolation and may have limited ability to adapt to new environmental pressures. The discovery of a new species in a remote area of Hawaii suggests that it may be an endemic island species, further increasing its risk of extinction due to habitat destruction.

Question 18

A species is considered biologically extinct when it has disappeared from the earth.

Accepted Answer

When a species is biologically extinct, it means that there are no longer any individuals of that species left on Earth. This is different from functional extinction, which refers to a population that is still present but no longer plays a significant role in their ecosystem.

Question 19

Extinction can occur as the result of habitat fragmentation.

Accepted Answer

Habitat fragmentation can lead to a loss of habitat connectivity which can result in isolated populations being more vulnerable to genetic and demographic factors that increase the risk of extinction.

Question 20

The most important reason to preserve wild species is to provide game hunting and fishing opportunities.

Accepted Answer

The most important reason to preserve wild species is to maintain biodiversity and functioning ecosystems. While some people may enjoy hunting and fishing, it is not the primary purpose of conservation efforts. The extinction of a species can have drastic impacts on the balance of an ecosystem, leading to cascading effects on other species and even impacting human wellbeing.

Quiz 8: Sustaining Biodiversity: Saving Species