Question 1

If all individuals in the last remaining population of a particular frog species were all highly related, which type of diversity would be of greatest concern when planning to prevent the species from going extinct?
A) global diversity
B) local diversity
C) ecosystem diversity
D) genetic diversity

Accepted Answer

When all individuals in a population are highly related, there is an increased risk of inbreeding and reduced genetic diversity. This lack of genetic diversity can make the population more susceptible to diseases, environmental changes, and other threats, making it difficult to adapt and recover. Therefore, genetic diversity would be of greatest concern when planning to prevent the species from going extinct.

Question 2

Burning fossil fuels releases oxides of sulfur and nitrogen. These air pollutants can be responsible for ________.
A) the death of fish in lakes
B) precipitation with a pH as high as 8.0
C) eutrophication of lakes
D) global temperature decrease

Accepted Answer

Burning fossil fuels releases sulfur and nitrogen oxides, which can lead to acid rain. Acid rain can lower the pH of water bodies, harming aquatic life and potentially causing the death of fish in lakes.

Question 3

Loss of biodiversity matters not only with regard to mammals or other vertebrates, but also microbes. Why are microbes worthy of discovery and protection from extinction?
A) Microbes play a role in digestion.
B) Microbes may produce unique proteins useful in genetic research.
C) Microbes are much greater in species number than any other taxa on Earth.
D) Microbes may be the most sensitive to the next large extinction event.

Accepted Answer

B

Question 4

Introduced species can have deleterious effects on biological communities by ________.
A) competing with native species for resources and displacing them
B) spreading rapidly in their new region
C) reducing erosion
D) increasing the biodiversity in their new region

Accepted Answer

Introduced species can outcompete native species for resources and displace them, leading to a decline in biodiversity and ecological function.

Choice B and C are incorrect because spreading rapidly and reducing erosion are not necessarily indicative of deleterious effects.

Choice D is incorrect because increased biodiversity can be positive, neutral, or negative depending on the context and species involved.

Question 5

Ecosystem services include processes that increase the quality of the abiotic environment. Which of the following processes would fall under this category?
A) Keystone predators have a marked effect on species diversity.
B) Green plants and phytoplankton produce the oxygen we breathe.
C) Bees, flies, and wasps pollinate many plants.
D) The presence of dams improves flood control.

Accepted Answer

The process of photosynthesis by green plants and phytoplankton produces oxygen, which is an abiotic factor that improves the quality of the environment for many organisms.

Option A is incorrect as it describes the impact of a predator on species diversity, which is a biotic factor, not an abiotic factor.

Option C is also incorrect as it involves the interaction between animals and plants, which is a biotic factor.

Option D is incorrect as the presence of dams is a human-driven activity, not a natural process, and it does not directly impact the abiotic environment.

Question 6

Of the following ecosystem types, which have been impacted the most by humans?
A) wetland and riparian
B) desert and high alpine
C) taiga and second-growth forests
D) tundra and arctic

Accepted Answer

Wetland and riparian ecosystems have been highly impacted by human activity such as draining for agriculture, urban development, and pollution from industrial and agricultural runoff. These activities destroy and fragment habitats, disrupt nutrient cycles and water flow, and negatively impact biodiversity.

Question 7

Which of the following observations provides the best evidence of a biodiversity crisis?
A) the incursion of a non-native species
B) increasing pollution levels
C) high rate of extinction
D) climate change

Accepted Answer

A high rate of extinction is a direct measure of biodiversity decline and loss. While the other options are also important factors in biodiversity loss, they do not provide direct evidence of a biodiversity crisis.

Question 8

Philippe Bouchet and colleagues conducted a massive survey of marine molluscs on the west coast of New Caledonia. For 20% of the total species that were located and identified, only a single specimen was found. What does that suggest about the diversity of molluscs in this area?
A) The west coast of New Caledonia is not an appropriate habitat for molluscs.
B) Many of the species from this 20% are probably rare.
C) They were not sampling uniformly throughout the area.
D) Many of the species from this 20% are most likely just dispersing through the area.

Accepted Answer

Finding only a single specimen for 20% of the total species suggests that these species are rare in the area.

Question 9

During the inventory of bacterial genes present in the Sargasso Sea, a deep isolated area in the middle of the Atlantic Ocean, a research team concluded that at least 1,800 bacterial species were present. Based on what you might predict about the habitat structure of such an area, what kind of bacterial diversity would you expect to see in tropical coral reef waters?
A) slightly greater genetic diversity
B) slightly smaller genetic diversity
C) markedly smaller genetic diversity
D) markedly greater genetic diversity

Accepted Answer

Tropical coral reef waters are known for their complex structures and diverse habitats, which typically support a markedly greater genetic diversity compared to more isolated and less structurally complex environments like the Sargasso Sea.

Question 10

Overharvesting encourages extinction and is most likely to affect ________.
A) animals that occupy a broad ecological niche
B) large animals with low intrinsic reproductive rates
C) most organisms that live in the oceans' coral reefs
D) edge-adapted species

Accepted Answer

Large animals with low intrinsic reproductive rates are most likely to be affected by overharvesting, as they cannot reproduce as quickly to replace population losses.

Question 11

Which of the following terms includes all of the others?
A) species diversity
B) biodiversity
C) genetic diversity
D) ecosystem diversity

Accepted Answer

Biodiversity includes all types of biological diversity, including species diversity, genetic diversity, and ecosystem diversity. Therefore, it is the most inclusive term.

Question 12

Suppose you attend a town meeting at which some experts tell the audience that they have performed a cost-benefit analysis of a proposed transit system that would probably reduce overall air pollution and fossil fuel consumption. The analysis, however, reveals that ticket prices will not cover the cost of operating the system when fuel, wages, and equipment are taken into account. As a biologist, you know that if ecosystem services had been included in the analysis, the experts might have arrived at a different answer. Why are ecosystem services rarely included in economic analyses?
A) Federal laws of the United States exclude their inclusion in any cost benefit analysis.
B) They have a low value and are usually not cost effective.
C) Ecosystem services only take into account abiotic factors that affect local environments.
D) Their cost is difficult to estimate, and people take them for granted.

Accepted Answer

Ecosystem services, such as air and water purification, waste decomposition, and pollination, provide vital contributions to human well-being and economic development. However, their value is difficult to estimate because they are often taken for granted, and their benefits are not usually reflected in market prices or financial transactions. This leads to ecosystem services being undervalued or ignored in economic analyses, resulting in incomplete or inaccurate evaluations of proposed projects or policies.

Question 13

Erwin and Scott used an insecticidal fog to knock down insects from the top section of a L. seemannii tree. The researchers identified over 900 species of beetles among the individuals that fell. Erwin also projected that this entire tree from top to bottom is host to about 600 arthropod species that are unique to this tree species and not found on any other tree species. There are approximately 50,000 species of tropical trees. Although it could not be entirely accurate, what would be the best way to estimate the total number of arthropod species?
A) Estimate the species density and then multiply by 50,000.
B) Multiply 600 by 50,000.
C) Multiply 50,000 by 900.
D) Add 900 to 600, and then multiply by 50,000.

Accepted Answer

Multiplying 600 by 50,000 estimates the total number of arthropod species by assuming each tree species hosts a similar number of unique arthropod species.

Question 14

Which of the following threats to biodiversity is targeted at specific species rather than groups of species?
A) introduced species
B) habitat destruction
C) increased levels of atmospheric carbon dioxide, a cause of global warming
D) overharvesting

Accepted Answer

Overharvesting is the process of harvesting an animal or plant resource to the point of diminishing returns. This is a direct threat to a particular species rather than a group of species. Introduced species, habitat destruction, and increased levels of atmospheric carbon dioxide are threats that affect multiple species at once.

Question 15

Researchers have been studying a rare population of 87 voles in an isolated area. Ten voles from a larger population were added to this isolated population. Besides having ten additional animals, what benefits are there to importing individuals?
A) There is no benefit other than increasing the overall population size.
B) Additional voles will strengthen competition and increase the survival of the fittest.
C) Additional animals would increase beneficial genetic drift.
D) Additional voles from a distant population will likely increase genetic diversity and reduce inbreeding.

Accepted Answer

Adding new voles from a distant population will likely increase genetic diversity and reduce inbreeding, which can improve the overall health and fitness of the population. This can also help prevent loss of genetic variability over time, improving the population's adaptability to changing environmental conditions.

Question 16

To better comprehend the magnitude of current extinctions, it will be necessary to ________.
A) differentiate between plant extinction and animal extinction numbers
B) focus on identifying more species of mammals and birds
C) identify more of the yet unknown species of organisms on Earth
D) use the average extinction rates of vertebrates as a baseline

Accepted Answer

Identifying more of the yet unknown species of organisms on Earth will provide a more accurate understanding of the current extinction rates.

Question 17

What is the biological significance of genetic diversity between populations?
A) Genes for traits conferring an advantage to local conditions are unlikely.
B) The population that is most fit would survive by competitive exclusion.
C) Genetic diversity reduces the probability of extinction.
D) Diseases and parasites are not spread between separated populations.

Accepted Answer

Genetic diversity reduces the probability of extinction because populations with more genetic variation are more likely to adapt and survive in changing environments, resist diseases and parasites, and prevent inbreeding depression.

Question 18

Which of the following statements regarding extinction is accurate?
A) A large percentage of species are immune from extinction; however, rates of extinction may increase with continued human impacts.
B) Extinctions occur only periodically, separated by long time spans with no extinctions.
C) Extinction is occurring at a similar rate now as compared to historical fossil evidence.
D) The small-population approach is inferior to the declining-population approach if the goal is to conserve the maximum number of species in a given region.

Accepted Answer

The answer of Which of the following statements regarding extinction...

Question 19

Tropical forests are being converted to farm or pasture land at an alarming rate, and one major focus is on the biodiversity and the impact to these ecosystems. What is a direct benefit to humans that helps explain why these forests need to be preserved?
A) This diversity provides areas for coffee growing.
B) Natural and undisturbed areas are important wildlife habitats.
C) The diversity could contain novel drugs for consumers.
D) The plant diversity provides shade, which lowers global warming.

Accepted Answer

Tropical forests contain a wealth of plant and animal diversity, making them potential sources of new drugs and medicines. Many of our current medications come from plants and animals found in these forests. By preserving these ecosystems, we are investing in the future of medicine and human health.

Question 20

The human impact that scientists determined has caused the most extinctions on record is ________, and beyond further losses from this impact, the other impact with the largest potential to cause future extinctions is ________.
A) introduced species; habitat loss
B) habitat loss; overharvesting
C) climate change; habitat loss
D) habitat loss; climate change

Accepted Answer

The first part of the question is asking for the human impact that has caused the most extinctions on record, which is habitat loss. The second part of the question is asking for the human impact with the largest potential to cause future extinctions, which is climate change. Therefore, the correct answer is D, habitat loss and climate change.

Quiz 56: Conservation Biology and Global Change

If all individuals in the last remaining population of a particular frog species were all highly related, which type of diversity would be of greatest concern when planning to prevent the species from going extinct?

Burning fossil fuels releases oxides of sulfur and nitrogen. These air pollutants can be responsible for ________.

Loss of biodiversity matters not only with regard to mammals or other vertebrates, but also microbes. Why are microbes worthy of discovery and protection from extinction?

Introduced species can have deleterious effects on biological communities by ________.

Ecosystem services include processes that increase the quality of the abiotic environment. Which of the following processes would fall under this category?

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

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

Philippe Bouchet and colleagues conducted a massive survey of marine molluscs on the west coast of New Caledonia. For 20% of the total species that were located and identified, only a single specimen was found. What does that suggest about the diversity of molluscs in this area?

Overharvesting encourages extinction and is most likely to affect ________.

Which of the following terms includes all of the others?

Which of the following threats to biodiversity is targeted at specific species rather than groups of species?

Researchers have been studying a rare population of 87 voles in an isolated area. Ten voles from a larger population were added to this isolated population. Besides having ten additional animals, what benefits are there to importing individuals?

To better comprehend the magnitude of current extinctions, it will be necessary to ________.

What is the biological significance of genetic diversity between populations?

Which of the following statements regarding extinction is accurate?

Tropical forests are being converted to farm or pasture land at an alarming rate, and one major focus is on the biodiversity and the impact to these ecosystems. What is a direct benefit to humans that helps explain why these forests need to be preserved?

The human impact that scientists determined has caused the most extinctions on record is , and beyond further losses from this impact, the other impact with the largest potential to cause future extinctions is .