module60REVIEW

649

In this module, we learned that the biodiversity of our planet is declining for a number of reasons. The primary causes of this decline are the loss of habitats and the fragmentation of habitats that species need to survive and reproduce. Exotic species are being moved around the world with the increased global movement of people and materials. Many populations of these exotic species remain small and cause no discernible harm, but some become invasive species that spread quickly and have harmful effects on native species. Overharvesting species can cause larger declines in population sizes and, in some cases, extinction. Current regulations within and among countries are designed to limit harvesting to sustainable levels, although these regulations are not always successfully enforced. Toxic compounds including pesticides, heavy metals, and spilled oil can also be detrimental to species either by direct lethal effects or by altering communities and ecosystems. Finally, climate change has the potential to alter populations and the long-term persistence of species, but more time is needed to determine if these predictions will come true. In the next module, we will examine past and current efforts to conserve biodiversity.

Module 60 AP® Review Questions

Question 1

1. The most significant cause of species decline and extinction throughout the world is

  1. habitat loss.

  2. overharvesting.

  3. pollution.

  4. climate change.

  5. invasive species.

Question 2

2. Invasive species are

  1. usually not a threat to biodiversity.

  2. rare in island habitats.

  3. successful due to a lack of natural enemies.

  4. mostly specialist species.

  5. often unable to compete effectively in the new environment.

Question 3

3. Passenger pigeons were driven extinct primarily by

  1. habitat loss.

  2. overharvesting.

  3. pollution.

  4. climate change.

  5. invasive species.

Question 4

4. The Lacey Act

  1. provides protected habitats for a number of threatened species.

  2. forbids the interstate shipping of illegally harvested plants and animals.

  3. provides harvesting quotas and prevents overharvesting.

  4. prevents the spread of invasive species to the United States.

  5. gives penalties for polluting ecosystems, especially water.

Question 5

5. The primary impact of climate change on species diversity is expected to be

  1. an increased number of extreme weather events.

  2. an increased variability in weather.

  3. decreased precipitation worldwide.

  4. changes in available habitat because of changing temperatures.

  5. the increased ability of species to disperse.