BSC 116 Ch 56 HW/Quiz

Suppose your friend says to you, "It doesn't matter so much anymore if species go extinct, as long as we figure out the genome of each species before it goes extinct." Which of the following statements correctly explain why species conservation still matters? Select all that apply. -Many species that are threatened could potentially provide crops, fibers, and medicines for human use. -Loss of one species may lead to loss of other species. -Loss of species may lead to loss of vital ecosystem services.

-Many species that are threatened could potentially provide crops, fibers, and medicines for human use. -Loss of one species may lead to loss of other species. -Loss of species may lead to loss of vital ecosystem services. (All three statements provide reasons for why species conservation matters. Ecologist Robert Costanza estimated the value of Earth's ecosystem services at $33 trillion per year. Read about ecosystem services.)

are possible? Select all that apply. -Population numbers of species that interacted with the extinct population may increase. -Genetic variation may be lost from the species as a whole. -The overall adaptive prospects of the species may decline.

-Population numbers of species that interacted with the extinct population may increase. -Genetic variation may be lost from the species as a whole. -The overall adaptive prospects of the species may decline. (All three possibilities may occur after the extinction of a local population. If one population becomes extinct, then the species may have lost some of the genetic diversity that makes microevolution possible. This erosion of genetic diversity in turn reduces the adaptive potential of the species. Because of the many interactions among populations of different species in an ecosystem, the local extinction of one species can impact other species in the ecosystem. Read about genetic and ecosystem diversity.)

Which size forest fragment would be most affected by habitat fragmentation over a given period of time? -100 hectares. -1000 hectares -10 hectares -1 hectares

1 hectares (The smallest fragments would be most affected by habitat fragmentation due to disturbances flowing into the fragment from the exterior.)

Which of the following is associated with the small-population approach to species conservation? See Concept 56.2 (Page 1264) -effective population size -extinction vortex -minimum viable population -All of the choices above are associated with the small-population approach to species conservation. -None of the choices above is associated with the small-population approach to species conservation.

All of the choices above are associated with the small-population approach to species conservation.

Which of the following statements is supported by the graph? -Because there is so much uncertainty in the forecasts, no conclusions can be drawn about how actions to reduce CO2emissions will affect the rate of global warming. -All of the computer-generated forecasts predict some global warming, but reducing the level of CO2 emissions will significantly slow the rate of increase. -If CO2 emissions cease immediately, global temperatures will stabilize near the 1900 level.

All of the computer-generated forecasts predict some global warming, but reducing the level of CO2 emissions will significantly slow the rate of increase.

Looking at the figure showing the results of forest fragmentation, what can be said about edge effects? -Biomass increases along the edges of forest fragments. -Species diversity decreases along the edges of forest fragments. -Fragmentation does not affect biomass. -Biomass declines along edges of forest fragments.

Biomass declines along edges of forest fragments.

Which of these three gases is most abundant in the atmosphere? -Methane (CH4) -Carbon dioxide (CO2) -Nitrous oxide (N2O) -The concentrations of the three gases are approximately equal.

Carbon dioxide (CO2)

Eutrophication is often caused by excess limiting-nutrient runoff from agricultural fields into aquatic ecosystems. This process results in massive algal blooms that eventually die and decompose, ultimately depleting the dissolved oxygen, killing large numbers of fish and other aquatic organisms. Predict which of the following human actions would best address the problem of eutrophication near agricultural areas? -Remove the algae before it dies and decomposes to prevent eutrophication from occurring. -After each eutrophication event, remove the dead fish and invertebrates to place on agricultural fields instead of fertilizer. -Determine critical nutrient loads required for certain crops, and do not exceed this amount during fertilizer application. -Determine which limiting nutrient is responsible for the algal bloom, and use other fertilizers to apply to crops.

Determine critical nutrient loads required for certain crops, and do not exceed this amount during fertilizer application.

In 1958 federal law restricted the movement of soil and plants from areas where fire ants were established. Why was this law unsuccessful in stopping the spread of fire ant colonies? -People were unaware of the federal law and, when they moved, transported plants bearing fire ant colonies. -A single mated queen can be transported without being noticed. -Many states originally thought to be free of fire ant colonies already had them. -People were unaware of the federal law and, when they moved, transported plants bearing fire ant colonies; moreover, a single mated queen can be transported without being noticed. -People were unaware of the federal law and, when they moved, transported plants bearing fire ant colonies; a single mated queen can be transported without being noticed; and many states thought to be free of fire ant colonies already had them.

People were unaware of the federal law and, when they moved, transported plants bearing fire ant colonies; a single mated queen can be transported without being noticed; and many states thought to be free of fire ant colonies already had them. (All of these are reasons that the federal law may have been unsuccessful at stopping the spread of fire ant colonies.)

Which of the following statements about the effects of forest fragmentation on plant biomass and species diversity is true? -Small forest fragments lose their species diversity at the same rate as large forest fragments. -The loss of plant biomass has a domino effect on other species that live in the forest fragment. -The loss of plant biomass correlates mostly with the death of understory plants. -Large forest fragments (>1000 hectares) are not affected by edge effects and their species diversity is expected to be stable over a long period of time.

The loss of plant biomass has a domino effect on other species that live in the forest fragment. (This phenomenon exacerbates the edge effects seen in forest fragments and causes a more rapid loss of species diversity in the fragment.)

True or false? Biologists studied the effects of forest fragmentation by calculating the difference between the amount of plant biomass in the edges of forest fragments and the interiors of unfragmented forest. -True -False

True (Through these studies, biologists found that the edge plots lost about 14 percent of their biomass every two years, starting at two years after the fragmentation occurred.)

From 1930 to 1939 fire ants spread inland about 60 miles from their point of introduction in Mobile, Alabama. What was the cause of their spread over this distance? -a natural spread -airplanes -being transported along with soil -being transported along with plants -dispersion via ship ballast

a natural spread (This rate of spread corresponds to a natural spread.)

Which of the following organisms was\were introduced by humans into the United States or its territories? See Concept 56.1 (Page 1261) -zebra mussels -brown tree snake -European starling -kudzu -all of the choices are correct

all of the choices are correct

Aquatic nitrate pollution can result in _____. -algal bloom -oxygen depletion -fish kills -hypoxia -an algal bloom that, when the algae die and are decomposed by bacteria, leads to hypoxia and the death of fish

an algal bloom that, when the algae die and are decomposed by bacteria, leads to hypoxia and the death of fish (This describes some of the consequences of aquatic nitrate pollution.)

Which of these are the two major sources of nitrate pollution in rivers? -the burning of fossil fuels by factories and cars -animal wastes and the burning of fossil fuels by cars -animal wastes and fertilizers -fertilizer runoff and the burning of fossil fuels by cars -animal wastes and the burning of fossil fuels by factories

animal wastes and fertilizers (According to an EPA study, animal wastes and fertilizer runoff are the two major sources of nitrate pollution.)

From 1940 to 1970 fire ants spread through many southern states, sometimes at a rate of 100 miles in a year. What was the cause of their spread over this distance? -a natural spread -airplanes -being transported along with soil and plants -being transported along with plants -dispersion via ship ballast

being transported along with soil and plants (This is the most likely explanation of the 1940-1970 spread.)

A human activity such as draining a wetland _________ ecosystem diversity. -decreases -has no effect on -increases

decreases

Extinction _________ species diversity. -decreases -has no effect on -increases

decreases

High genetic diversity within a species ___________ the likelihood that the species can adapt to new environmental conditions. -decreases -has no effect on -increases

increases

Low genetic diversity within a species _________ the likelihood that the species may go extinct -decreases -has no effect on -increases

increases

The number of habitat types ________ when ecosystem diversity increases. -decreases -has no effect on -increases

increases

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

large animals with low intrinsic reproductive rates

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? -markedly smaller genetic diversity -slightly greater genetic diversity -markedly greater genetic diversity -slightly smaller genetic diversity

markedly greater genetic diversity

The estimated density or number of individuals needed for a species to maintain or increase its numbers in a region is the _____. See Concept 56.2 (Page 1264) -Hardy-Weinberg equilibrium -metapopulation -endemic population -minimum viable population (MVP) -stochastic population

minimum viable population (MVP) (The smallest number of individuals needed to maintain a species or population is the minimum viable population.)

Which of these would NOT contribute to a global increase in temperature? -deforestation -increasing the use of gasoline-burning vehicles -planting trees -increasing the industrial release of carbon dioxide -increasing the amount of animal life on Earth

planting trees (Trees remove more carbon dioxide from the atmosphere than they release into the atmosphere. By removing carbon dioxide, they reduce the greenhouse effect and this would contribute to a reduction in global temperature.)

Techniques used, or are being considered for use, in controlling the spread of fire ants include _____. -setting baits that kill the queen when they are carried back to the nest -applying chemical powders that kill the colony -introducing a protist to infect the fire ant queen and her eggs -introducing a fly that lays eggs in fire ants so that the eggs will hatch into larvae that eat their way into the ants' heads, which will then fall off -setting baits that kill the queen when they are carried back to the nest, applying chemical powders that kill the colony, introducing a protist to infect the fire ant queen and her eggs, and introducing a fly that lays eggs in fire ants so that the eggs will hatch into larvae that eat their way into the ants' heads, which will then fall off

setting baits that kill the queen when they are carried back to the nest, applying chemical powders that kill the colony, introducing a protist to infect the fire ant queen and her eggs, and introducing a fly that lays eggs in fire ants so that the eggs will hatch into larvae that eat their way into the ants' heads, which will then fall off (The first two of these are being done and the second two are being investigated as possible techniques for controlling fire ants.)

Switching from fossil fuels to _____ energy would significantly decrease the release of carbon dioxide into the atmosphere. -solar -nuclear -geothermal -solar and geothermal -solar, nuclear, and geothermal

solar, nuclear, and geothermal (All of these energy sources would decrease the release of carbon dioxide into the atmosphere. However, the use of nuclear reactors is associated with other problems.)