FRQ

Biological diversity, or biodiversity, has become a topic of great concern among conservationists. Biodiversity is often used by scientists and policy makers to help determine the health of ecosystems. Describe TWO characteristics shared by ecosystems that have high biodiversity. Identify TWO specific human activities that result in a loss of biodiversity, and explain how each activity lowers biodiversity. For each human activity you discussed in (b), propose a practical strategy (other than simply banning the activity) to reduce the loss of biodiversity. Describe ONE naturally occurring factor that could lead to a loss of biodiversity. Describe TWO ecological benefits that greater biodiversity provides.

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Dams are built by humans for various purposes including hydroelectric power generation and control of downstream flooding. (a) Explain how electricity is generated at a hydroelectric dam. (b) Identify TWO economic benefits, other than hydroelectric power generation and control of downstream flooding, associated with dams. (c) Describe one ecological benefit of seasonal flooding of the floodplain of a free-flowing river. (d) Some dams have been removed from rivers. Explain how removal of a dam can benefit fish populations. Describe one negative environmental consequence of removing a dam from a river (other than effects on fish populations). (e) Dams are also built by beavers, a keystone species in some North American ecosystems. (i) Define keystone species. (ii) Describe how dams built by beavers can make beavers a keystone species in some ecosystems.

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Other than showing which organisms are consumed by other organisms, describe what is indicated by the direction of the arrows in the diagram. As the amount of sea ice has decreased, larger expanses of the Arctic Ocean are now completely free of sea ice for several weeks each summer. Ringed seals, the preferred prey of polar bears, come to holes in the sea ice to breathe. Describe how the change in sea ice habitat is affecting polar bears' ability to hunt and feed. Explain how melting sea ice leads to a feedback loop that increases Arctic warming. Many species, including some whales and birds, will travel thousands of kilometers during annual migrations. Provide one reason a species may migrate a long distance. The North Atlantic right whale migrates between subtropical and polar waters annually. Nearly 50 percent of right whale deaths are due to human activities. Describe one commercial activity, other than whaling, that may result in the death of right whales. Describe one strategy that could reasonably be implemented to decrease right whale deaths caused by the commercial activity you described in part (ii). BoldItalicUnderline

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Plate-tectonic theory states that the Earth's lithosphere is broken into very slowly moving pieces or plates.Plate movements over vast stretches of time have led to the current orientation of our continents and oceans. Individual events along plate boundaries, such as earthquakes and volcanic eruptions, pose periodic threats to human activity and ecosystems. The "Ring of Fire" is a term that describes the location of increased seismic and volcanic activity around the margins of the Pacific Ocean basin. On the map above, each dot represents a volcano or an earthquake. Japan, Indonesia, and the Philippines are examples of volcanic island chains that have formed along subduction zones between plates in the western Pacific. Describe what happens when two tectonic plates collide along a subduction zone. Explain how subduction leads to volcanic activity. Although the landscape following a volcanic eruption may appear unable to support ecological communities, over time the area can be transformed through succession. What is primary succession? Explain how primary succession can lead to soil formation on a newly formed volcanic landscape. In addition to volcanic activity, highly destructive tsunamis are generated along Pacific Plate subduction zones. Explain how a tsunami is generated along a subduction zone. Describe one negative ecological impact that tsunamis have on coastal environments. Southern California experiences periodic devastating earthquakes along the San Andreas Fault, which is a transform boundary located along the eastern edge of the Pacific Plate. Describe what happens to the tectonic plates along a transform boundary at the moment when an earthquake occurs. Describe what happens to the tectonic plates along a transform boundary during the time between earthquakes.

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The map above show the town of Fremont, where biologists have noted that the population of a certain species of bird has been declining over the past several years. This bird species is now found only in the wooded area on the western edge of the city. Developers view this wooded area as prime real estate and have recommended to the Fremont City Council that the area be zoned for single-family housing. A group of citizens concerned about the bird species and its habitat recommended to the council that future urban expansion be directed toward the eastern portion of the city and that the wooded area be preserved. (a) Identify and briefly describe two federal laws or regulations that might apply to this situation. (b) Assume that the Fremont City Council votes to preserve the wooded area. explain the positive and negative consequences of this action. Include long- and short-term effects on the environmental, economic, and recreational needs of the citizens of Fremont. (c) Assume that the Fremont City Council votes against preserving the wooded area. Propose and defend an alternative plan that both protects the bird species and provides for urban expansion. BoldItalicUnderline

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The zebra mussel, a mollusk native to Eurasia, was first discovered in the Great Lakes of North America in 1988. Zebra mussels attach to solid substrates and are filter feeders. Adult zebra mussels can survive for several days or even weeks out of water if the temperature and humidity are favorable. An adult female zebra mussel can produce as many as one million eggs per year. The recent range of occurrence of zebra mussels in the United States is indicated by shading in the map above. (a) Why are zebra mussels located primarily in areas in the eastern United States rather than in the western United States? (b) How are zebra mussels introduced into isolated lakes? Describe one viable method for preventing the spread of zebra mussels into isolated lakes. (c) Identify and explain one impact that zebra mussels can have on aquatic ecosystems. (d) Identify another invasive species, either terrestrial or aquatic, and describe one negative impact it has had. (e) One strategy for controlling an invasive species has been to introduce another nonnative species to control it; this strategy can often have unintended results. Give a specific example of the use of this strategy and discuss a negative impact of introducing a nonnative species to control an invasive species. (f) Discuss TWO specific characteristics of invasive species that enable them to thrive in new environments.

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