A

In Clackamas, Oregon, a stand of hybrid poplar trees was planted on an area of land that is contaminated with volatile organic compounds (VOCs). Why would someone purposely plant trees in an area with contaminated soil?
A) to use the trees as a means of phytoremediation
B) to use the trees as a means of eliminating insect species that consume nearby endemic plants
C) to use the trees for lumber for houses
D) to see if animals will make nests in trees that grow in contaminated soil.

 D

While habitat destruction by humans creates fragmented ecosystems, fragmentation can also occur due to natural processes. Which of the following natural processes would most likely create a fragmented ecosystem?
A) thunderstorm
B) glacier movement
C) blizzard
D) volcanic eruption

 D

If current trends in global warming continue for the next 50 years, where will the greatest effects of global warming likely be felt?
A) the continental United States
B) the Pacific Ocean
C) the Mississippi River
D) Russia

 A

As global temperatures continue to rise, what is a likely outcome?
A) loss of populations of fish
B) greater overharvesting of medicinal plant species
C) less greenhouse gas emissions
D) formation of new glaciers

 C

Suppose a species of wild boar (a type of pig) is actively hunted when it is at a young age because at that stage of its development the meat of the boar is particularly tender. What is a likely outcome if this species is overharvested?
A) The wild boar population will dwindle because their food source will disappear due to habitat loss.
B) The wild boar population will increase because older boars will continue to survive.
C) The wild boar population will dwindle and potentially go extinct if not enough boars that can reproduce are left to mate.
D) The wild boar population will increase because boundaries will help separate boars from humans.