Ospreys and other top predators are most severely affected by pesticides such as PCBs because theya. are especially sensitive to chemicals.b. have very long life spans.c. store the pesticides in their tissues.d. consume prey in which pesticides are concentrated.

Current rates of species extinction appear to be approximately historical rates of extinction.a. equal to;b. 10 times lower than;c. 10 times higher than;d. 50 to 100 times higher than;e. 1000 to 10,000 times higher than

Which of the following is characteristic of endemic species?a. They are often found in biodiversity hot spots.b. They are distributed widely in the biosphere.c. They require edges between ecosystems.d. They are often keystone species whose presence helps to structure a community.

What is the primary threat in marine environments?

Which of the following strategies would most rapidly increase the genetic diversity of a population in an extinction vortex?a. Establish a reserve that protects the population's habitat.b. Introduce new individuals transported from other populations of the same species.c. Sterilize the least fit individuals in the population.d. Control populations of the endangered population's predators and competitors.

Why is the common phrase 'humans and animals' not accurate in biology? Suggest one way that a more scientific outlook could boost conservation efforts.

Which cause of extinction results from humans' direct use of a species?a. overexploitation;b. habitat fragmentation;c. pollution;d. introduction of competitors or predators;e. global warming

Which of the following statements about protected areas established to preserve biodiversity is true? (A) About 25% of Earth's land area is now protected. (B) National parks are the only type of protected area. (C) Management of a protected area does not need to be coordinated with management of the surrounding area. (D) It is especially important to protect biodiversity hot spots

Of the following statements about protected areas that have been established to preserve biodiversity, which one is not correct?a. About 25% of Earth's land area is now protected.b. National parks are one of many types of protected areas.c. Management of a protected area should be coordinated with management of the land surrounding the area.d. It is especially important to protect biodiversity hot spots.