60) Which of the following statements about protected areas that have been established to
preserve biodiversity are correct?
I) About 25 percent of Earth’s land area is now protected.
II) National parks are one of many types of protected areas.
III) Management of a protected area should be coordinated with management of the land
surrounding the area.
IV) It is especially important to protect biodiversity hot spots.
A) only I and III
B) only II and IV
C) only I, II, and IV
D) only II, III, and IV
61) Eutrophication is often caused by excess limiting nutrient runoff from agricultural fields into
aquatic ecosystems. This results in massive algal blooms, which eventually die and decompose,
ultimately depleting the dissolved oxygen and killing large numbers of fish and other aquatic
organism. Predict which of the following human actions would best address the problem of
eutrophication near agricultural areas?
A) After each eutrophication event, remove the dead fish and invertebrates to place on
agricultural fields instead of fertilizer.
B) Determine which limiting nutrient is responsible for the algal bloom and use other fertilizers
to apply to crops.
C) Remove the algae before it dies and decomposes to prevent eutrophication from occurring.
D) Determine critical nutrient loads required for certain crops and do not exceed this amount
during fertilizer application.
62) Elevated carbon dioxide levels have been shown to contribute to the greenhouse effect,
resulting in an increase in mean global temperature. Ecosystems where the largest warming has
already occurred include snow-covered northern coniferous forests, tundra, and arctic sea ice
habitats. Which statement best explains how the elimination of ice-covered ecosystems affects
the rise or fall in global temperature?
A) Melting ice releases dissolved ozone gas, which adds to the greenhouse effect.
B) More reflective surfaces of ice are replaced with darker, more absorptive surfaces, thereby
contributing to the warming trend.
C) Large-scale ice melts actually contribute toward lowering global temperatures by decreasing
salinity of the oceans.
D) Carbon dioxide levels are lowered as a result of greater volume of water to accommodate
greater dissolved gas.