Practice Exam 3 - Environmental Science - page 310

76. D A kelp forest provides shelter for fish, serves as a food supply for many invertebrates, can provide
components of cosmetic products, and protects the coastline. Kelp forests do not help to reduce the ef-
fects of eutrophication, though, which is caused by an influx of nutrients into an aquatic environment.
77. C Ocean currents transport energy as they move, with water temperature being a major driver of this
circulation. Surface waters are warm, less dense, and less saline than deeper waters are. Surface waters
are warmed by solar radiation in equatorial regions. As the warm waters move away from the equator,
they cool and sink. As cold water moves toward warmer regions, the water warms and some of it rises.
This constant rising and sinking of ocean water helps to move the water and circulate nutrients and
gases.
78. C Co-evolution occurs when hosts and parasites develop adaptations in response to one another. As
one organism develops an adaptation through the process of natural selection, the other organism may
adapt in response to the other organism's adaptation.
79. A Focusing conservation on one charismatic species raises awareness of the need to protect an entire
ecosystem. Because some species are more appealing to the public, they can be used to help conserva-
tion efforts not only for the species itself, but also for other species and the ecosystem as a whole.
80. C Modern growth has low birth and death rates. Low death rates are due to efficient medical care and
low infant mortality, while low birth rates are due to factors such as increased use of contraception, fe-
males joining the workforce, and family planning. During the Agricultural Revolution, birth and death
rates were both high because of high infant mortality, poor sanitation and healthcare, and the need for
children to help with farming.
81. A Tropical storms and hurricanes are believed to be increasing in intensity in recent decades due to
warming tropical sea surface temperatures. It is possible that the warming water temperatures are due to
global warming, but this point is still being studied and debated.
82. E Placer mining uses running water to separate out the heavier minerals from the lighter ones.
83. A In open pit mining, quarries are created with terraced sides to allow access into the mine.
84. B Subsurface mines often are used in coal mining. Particles are disrupted in this process and become
airborne. If not managed properly and without the proper protective gear, this environment can become
a health issue affecting the respiratory system.
85. C Critics propose that the negative consequences of producing genetically modified foods include the
following: the increasing need for more powerful pesticides and herbicides because of the growing res-
istance of pests and weeds, the destruction of native crops because of genetic contamination from wind-
blown and water-carried genetically modified seeds, the possibility of exacerbating allergies in people,
and the potential to create new disease because bacteria and viruses are sometimes used to create genet-
ically modified foods. The ability for foods to stay fresh longer, giving them the ability to be transpor-
ted farther and have a longer shelf life, is considered a benefit of genetically modified crops.
86. B An evolutionary adaptation in which different species divide a limited resource by specializing in
different ways is considered resource partitioning. This allows similar species to survive within the
same habitat by focusing survival efforts in unique ways. Note that this division of habitat occurs over
generations through the process of natural selection.
87. C With increasing altitude, atmospheric pressure decreases. This is because, at high altitudes, fewer air
particles are pushing down from above.