Chapt 43 Flashcards

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

tropical rain forest


Study the information in the figure about quail habitats. Assuming that only one quail can occupy a habitat where all cover requirements are met, what is the maximum number of quail that could inhabit any of the hypothetical plots shown?



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?

Their cost is difficult to estimate and people take them for granted.


Your friend is wary of environmentalists' claims that global warming could lead to major biological change on Earth. Which of the following statements can you use in response to your friend's suspicions?

All statements listed could be used.

Sea levels will likely rise, displacing as much as 50% of the world's human population.

Global warming could have significant effects on agriculture in the United States.

Through measurements and observations, we know that CO2levels and temperature fluctuations are directly correlated, even in prehistoric times.

We know that atmospheric carbon dioxide has increased over the past 150 years


Invasive species are introduced by humans to new geographic locations and

All of the choices are correct.

spread because they encounter none of their natural predators.

can outcompete and displace native species for biotic and abiotic resources.

are successful in colonizing a novel area.

are usually considered pests by ecologists.


Estimates of current rates of extinction

indicate that rates may be greater than the mass extinctions at the close of the Cretaceous period.


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?

The current rate of extinction is high and human activities threaten biodiversity at all levels.


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

high rate of extinction


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

the rate of extinction is higher than background extinction rates.


Which of the following terms includes all of the others?



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

an endangered species is closer to extinction.


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



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

All of the options are correct.

potential loss of medicines and other products yet undiscovered from threatened species.


the risk to global ecological stability.

potential loss of genes, some of which may code for proteins useful to humans.


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

potential loss of ecosystem services on which people depend.


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

habitat destruction


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

alteration or destruction of the physical habitat.


What is the biological significance of genetic diversity between populations?

Genes for adaptive traits to local conditions make microevolution possible.


Introduced species can have deleterious effects on biological communities by

All of the options are correct.

preying on native species.

competing with native species for food or light.

competing with native species for space or breeding/nesting habitat.

displacing native species


Overexploitation encourages extinction and is most likely to affect

large animals with low intrinsic reproductive rates.


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?

The bats pollinate the trees and disperse seeds.


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

wetland and riparian


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

the extirpation of many of the island's bird and reptile species.


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

importing an Asian insect into the United States to control a weed that competes with staple crops


Which of the following is a type of research in which a conservationbiologist would be involved?

All of the options are correct.

studying species diversity and interaction in the Florida Everglades, past and present

reestablishing whooping cranes in their former breeding grounds in North Dakota

determining the effects of hunting white-tailed deer in Vermont

studying the population ecology of grizzly bears in Yellowstone National Park


Which of the following species was driven to extinction by overexploitation by hunters/fishermen?

the great auk


Which of the following conditions is the most likely indicator of a population in an extinction vortex?

Genetic measurements indicate a loss of genetic variation over time.


Review the formula for effective population size. Imagine a population of 1,000 small rodents. Of these, 300 are breeding females, 300 are breeding males, and 400 are nonbreeding juveniles. What is the effective population size?



If the sex ratio in a population is significantly different from 50:50, then which of the following will always be true?

The effective population size will be less than the actual population size.


Which of the following life history traits can potentially influence effective population size (N e)?

All of the options are correct.

gene flow between geographically separated populations

maturation age

genetic relatedness among individuals in a population

population size


The word triage originated during World War I and was first used by French doctors in prioritizing patients based on the severity of their wounds, because there were more wounded soldiers in need of urgent care than there were resources to treat them. Conservation biologists have to make similar determinations with degraded ecosystems. Which of the following is the most important consideration when it comes to managing for maintenance of biodiversity?

determining which species is most important for conserving biodiversity as a whole


The primary difference between the small-population approach (S-PA) and the declining-population approach (D-PA) to biodiversity recovery is

S-PA is interested in bolstering the genetic diversity of a threatened population rather than the environmental factors that caused the population's decline.


The long-term problem with red-cockaded woodpecker habitat intervention in the southeastern United States is

the social organization of the red-cockaded woodpecker precludes the dispersal of reproductive individuals.


Managing southeastern forests specifically for the red-cockaded woodpecker

contributed to greater abundance and diversity of other forest bird species.


Which of the following is true about the current research regarding forest fragmentation?

Fragmented forests support a lesser biodiversity because the forested-adapted species leave, and only the edge and open-field species can occupy fragmented forests.


According to the small-population approach, what would be the best strategy for saving a population from extirpation?

introducing individuals from other populations to increase genetic variation


Relatively small geographic areas with high concentrations of endemic species and a large number of endangered and threatened species are known as

biodiversity hot spots.


How is habitat fragmentation related to biodiversity loss?

Populations of organisms in fragments are smaller, and thus more susceptible to extinction.


Brown-headed cowbirds utilize fragmented forests effectively by

parasitizing the nests of forest birds, and feeding on open-field insects.


Which of the following is consistent with forest fragmentation research?

Forest-interior species show declines in small patch communities.


How are movement corridors potentially harmful to certain species?

They spread disease and parasites.


Biodiversity hot spots are not necessarily the best choice for nature preserves because

a hot spot for one group of organisms may not be a hot spot for another group.


The success with which plants extend their range northward following glacial retreat is best determined by

their seed dispersal rate


As the climate changes because of global warming, species' ranges of plants in the Northern Hemisphere may move northward, using effective reproductive adaptations to disperse their seeds. The trees that are most likely to avoid extinction in such an environment are those that

have seeds that are easily dispersed by wind or animals.


If global warming continues at its present rate, which biomes will likely take the place of the coniferous forest (taiga)?

temperate broadleaf forest and grassland


Which of the following investigations would shed the most light on the future distribution of organisms in temperate regions that are faced with climate change?

Look at the climatic changes that occurred since the last ice age and how species redistributed as glaciers melted, then make predictions on future distribution in species based on past trends.


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

All of the options are correct.

the death of fish in lakes.

precipitation with a pH as low as 3.0.

direct damage to plants by leaching nutrients from the leaves.

calcium deficiency in soils.


What is the biggest problem with selecting a site for a preserve?

Making a proper selection is difficult because the current environmental conditions of almost any site may change in the future because of climate change or other factors.


What is a critical load?

the amount of added nutrient that can be absorbed by plants without damaging ecosystem integrity


The use of DDT as an insecticide in the United States has been outlawed since 1971, yet is still a problem for certain top-level carnivores in the United States. Which of the following choices best explains this apparent incongruity?

DDT is still used for mosquito control in tropical countries, and certain migratory predators can be affected by a seasonal biomagnification.


Agricultural lands frequently require nutrient augmentation because

the nutrients that become the biomass of plants are not cycled back to the soil on lands where they are harvested.


Which of the following refers to the reflecting and absorption of infrared radiation by atmospheric methane, carbon dioxide, and water?

greenhouse effect


What is caused by excessive nutrient runoff into aquatic ecosystems?



What causes extremely high levels of toxic chemicals in fish-eating birds?

biological magnification


The biggest challenge that Costa Rica will likely face in its dedication to conservation and restoration in the future is

the pressures of its growing population.


Which of the following nations has become a world leader in the establishment of zoned reserves?

Costa Rica


Which of the following is most key to understanding the demographic transition in human population growth?

voluntary reduction of family size


Which statement is true with regard to human population growth?

Its rate of growth is slowing.


The main goal of sustainable development is to

use natural resources such that they do not decline over time.


Which of the following best illustrates human efforts to improve environmental sustainability?

increasing our reliance on renewable sources of energy


Which of the following best illustrates the sustainable use of a resource?

Huge windmills in Texas are able to capture 50% of the wind energy in a specific region.


The concept of sustainable development emphasizes

the needs of future generations.


Which one of the following is the most sustainable source of energy?

hydroelectric dams