Question 1

According to most conservation biologists, the single greatest threat to global biodiversity is

Accepted Answer

Alteration or destruction of the physical habitat, such as deforestation, desertification, and urbanization, is considered the single greatest threat to global biodiversity. This is because it directly impacts and reduces the amount of suitable habitat available for many species, leading to habitat loss, fragmentation, and degradation. These changes can disrupt ecosystem processes, alter species interactions, and ultimately lead to declines or extinctions of species. While the other factors listed (such as pollution, overexploitation, and climate change) are also significant threats to biodiversity, they are generally considered to be secondary to habitat loss and degradation.

Question 2

What term did E. O. Wilson coin for our innate appreciation of wild environments and living organisms?

Accepted Answer

E. O. Wilson coined the term "biophilia" to describe our innate love and appreciation for living organisms and wild environments.

Question 3

Which of the following examples poses the greatest potential threat to biodiversity?

Accepted Answer

D

Question 4

Which of the following is the most direct threat to biodiversity?

Accepted Answer

Habitat destruction is the most direct threat to biodiversity because it directly removes the physical environment necessary for species to survive and reproduce. This can include deforestation, urbanization, and other forms of land use change that result in the loss of natural habitats. The loss of habitat also indirectly affects other threats to biodiversity, such as overexploitation of species and climate change.

Question 5

Although extinction is a natural process, current extinctions are of concern to environmentalists because

Accepted Answer

The main concern about current extinctions is the high rate at which they are occurring, exceeding natural, background extinction rates. This rapid loss of biodiversity is largely attributed to human activities such as habitat destruction and climate change. Option A is incorrect because while the number of species going extinct at present is of concern, it is not the primary issue. Option B is incorrect because introduced species are only one of many factors contributing to current extinctions. Option D is incorrect because current extinctions are affecting both animal and plant diversity. Option E is incorrect because there is a genuine concern regarding current extinction rates.

Question 6

What is the biological significance of genetic diversity between populations?

Accepted Answer

Genetic diversity allows for the existence of genes that may provide an adaptive advantage to certain populations in local conditions, leading to microevolution and potential speciation over time. This can help species thrive in changing environments and increase their chances of survival.

Question 7

Of the following ecosystem types, which have been impacted the most by humans?

Accepted Answer

Wetland and riparian ecosystems have been heavily impacted by humans through dredging, draining, and filling for agricultural and urban development. Wetlands provide important ecosystem services, such as water filtration and flood control, and are important habitats for numerous species. Riparian ecosystems, which are found along rivers and streams, have also been altered through dam construction, channelization, and water withdrawal. These ecosystem types are considered some of the most threatened globally due to human activities.

Question 8

Overexploitation encourages extinction and is most likely to affect

Accepted Answer

Large animals with low intrinsic reproductive rates, such as elephants or rhinoceroses, are particularly susceptible to overexploitation because they cannot reproduce quickly enough to replace those removed from the population.

Question 9

Invasive species are introduced by humans to new geographic locations and

Accepted Answer

All of the choices are correct. Invasive species are successful due to a combination of factors, including their ability to colonize new areas, lack of predators, competitive advantages over native species, and often being considered pests by ecologists.

Question 10

Estimates of current rates of extinction

Accepted Answer

The answer of Estimates of current rates of extinction
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Question 11

Which of the following ecological locations has the greatest species diversity?

Accepted Answer

Tropical rain forests have the greatest species diversity of all ecological locations, with estimates ranging from 50-80% of Earth's species residing in these areas.

Question 12

The introduction of the brown tree snake in the 1940s to the island of Guam has resulted in

Accepted Answer

The introduction of the brown tree snake to Guam has resulted in the extirpation (local extinction) of many of the island's bird and reptile species. The snake is an invasive species and has had a devastating impact on the native wildlife of Guam.

Question 13

Extinction is a natural phenomenon. It is estimated that 99% of all species that ever lived are now extinct. Why then do we say that we are now experiencing an extinction (loss of biodiversity) crisis?

Accepted Answer

The current rate of extinction is high and human activities threaten biodiversity at all levels. While extinction is a natural phenomenon, it is the rate of extinction that is the issue. The current rate of extinction is estimated to be 100 to 1,000 times higher than the natural background extinction rate, and this accelerated rate is largely due to human activities such as habitat destruction, introduction of invasive species, over-harvesting, pollution, and climate change. This loss of biodiversity has significant implications for ecosystem health, human well-being, and the planet's ability to sustain life.

Question 14

Which of the following provides the best evidence of a biodiversity crisis?

Accepted Answer

The high rate of extinction provides the best evidence of a biodiversity crisis. Extinction occurs when a species disappears completely from the planet. A high rate of extinction is an indication that the diversity of species is declining, which is a clear sign of a crisis.

Question 15

The most serious consequence of a decrease in global biodiversity would be the

Accepted Answer

Decreases in global biodiversity result in a potential loss of ecosystem services which people depend on, such as pollination, nutrient cycling, and water filtration. This loss could have negative impacts on human health, food security, and overall well-being. The other options presented in the question are not the most significant consequences of decreased global biodiversity.

Question 16

Which of the following terms includes all of the others?

Accepted Answer

Biodiversity is the most inclusive term as it encompasses all levels of biological organization, including species diversity, genetic diversity, and ecosystem diversity. Species diversity refers to the variety of species within a particular region, while genetic diversity pertains to the variation in genes among individuals within a species. Ecosystem diversity refers to the variety of ecosystems within a given region, which can include multiple species and genetic diversity. Species richness is a measure of the number of species in a particular area and is a component of species diversity.

Question 17

How might the extinction of some Pacific Island bats called "flying foxes" threaten the survival of over 75% of the tree species in those islands?

Accepted Answer

The answer of How might the extinction of some Pacific...

Question 18

We should care about loss in biodiversity in the populations of other species because of

Accepted Answer

All of the options are correct. Loss of biodiversity can impact our emotional and psychological well-being (biophilia), as well as have practical implications for medical research and the development of new products from natural resources. It can also lead to the loss of valuable genes and proteins, and ultimately threaten the overall stability of global ecosystems.

Question 19

According to the U.S. Endangered Species Act (ESA), the difference between an endangered species and a threatened one is that

Accepted Answer

According to the U.S. Endangered Species Act (ESA), an endangered species is one that is in danger of extinction throughout all or a significant portion of its range, while a threatened species is one that is likely to become endangered in the near future. Therefore, an endangered species is closer to extinction than a threatened one.

Question 20

Introduced species can have deleterious effects on biological communities by

Accepted Answer

All of the options are correct. Introduced species can have multiple negative impacts on native species and their habitats, including preying on native species, competing with them for resources like food or breeding/nesting habitat, and displacing them from their natural range. These impacts can lead to reduced biodiversity, altered ecosystems, and even extinction of native species.

Quiz 43: Global Ecology and Conservation Biology