Practice Exam 3 - Environmental Science - page 305

9. D 1 CFL averages 10,000 hours, while an incandescent bulb average 1,000 hours. Therefore, you will
need 10 incandescent bulbs to have 10,000 hours (10,000 ÷ 1,000 = 10). The total cost of the energy for
the incandescent bulbs is $10 × 10 bulbs = $100, so the savings is $100 - $25 = $75.
10. D If located a great distance from a municipal treatment center, a house is most likely using a septic
system to collect and treat sewage.
11. D A telephone ringing is not considered noise pollution because the decibel level from the telephone is
below the level considered harmful.
12. C The mid-Atlantic ridge is a divergent plate boundary, meaning the plates are moving away from each
other.
13. C The grassland has a thick O (organic) horizon. Deserts, semi-desert, and chaparral have relatively
thin O horizons. The same is true in a tropical rain forest, in which dead plants and animals decay relat-
ively quickly and live plants soon absorb the nutrients, leaving a thin O horizon.
14. B The parent material is the lowest level of the soil horizon and is comprised of the bedrock material.
15. C The grasslands of the United States are called prairies. The pampas are the grasslands of temperate
South America, llanos are the grasslands of tropical South America, steppes are the grasslands of
Europe, and veld are the grasslands in Africa.
16. A The greatest threat to the survival of terrestrial species is the loss of habitats. The destruction of hab-
itat occurs when land is cleared and altered for homes, businesses, and food production. Notice that
each of this question's incorrect answers can lead to habitat loss, but habitat loss itself is the most com-
mon threat.
17. D The greatest threat to aquatic species is overharvesting, which is the overfishing of organisms as a
food source for humans or as a food source for other species that are grown for human consumption.
Cod, salmon, sole, and tuna are just some of the species that have been overharvested. Notice that this
question's incorrect answers are themselves also dire threats.
18. B Subsidies are based on the location of agriculture, mining, forestry, and other businesses, not on the
location of current population centers.
19. E Built-in resistance is an advantage of genetically modified crops. Crops have now been created that
contain resistance to disease and pests, reducing or eliminating the need for pesticides. Unknown long-
term effects on human health and the destruction of native food sources are arguments against the use
of genetically modified crops.
20. E Clear-cutting cuts down all the trees in the area, leaving soil bare and subject to erosion. It also re-
duces habitat and shelter for animals and leaves a minimal basis for the forest to reseed itself and, thus,
grow back.
21. A Love Canal was a former canal in upstate New York where a large number of steel drums containing
toxic chemicals were buried. Eventually the land was covered and sold to a local community for a
school and housing. The drums rusted and the chemicals leaked, seeping through the soil and asphalt
and contaminating the soil and groundwater. This led to birth defects, cancers, and other human health
issues.
22. D Lake Erie was one of the most polluted lakes in the United States as a result of polluted rivers such
as the Cuyahoga River flowing into the lake, as well as heavy industry along the lake that ultimately
lead to a large fish die-off in 1969.