1) Americans use about __________ times as much energy as the world average.
A) 20 B) 1.5 C) 5 D) 10 E) 2

2) Rabbits were introduced to Australia about 100 years ago for the purposes of hunting. They have been multiplying, eating up the native vegetation, and destroying the native habitat of other small animals, ever since. In the 1950s, in order to control the rabbit population, government scientists released the myxomatosis virus. The virus, which dramatically reduced the rabbit population, is an ex of
A) a predator.
B) a parasite.
C) the effect of migration on growth.
D) a cyclical pattern of growth.

3) Environmental resistance is a limit imposed on population growth by
A) birth rates.
B) the abiotic environment only.
C) both the biotic and abiotic environment.
D) the biotic environment only (predators, competitors).
E) death rates

4) Which BEST describes the reason for the very rapid growth of the human population in the last 8,000 years?
A) Humans have few offspring but their young survive at a high rate
B) Technology has allowed the species to overcome some environmental resistance.
C) Climatic change has allowed the human species to expand its range.
D) The biotic potential for humans has increased.
E) Environmental resistance does not apply to humans.

5) If similar species each occupy a smaller niche when they live together than they would if they lived alone, they are said to be
A) partitioning resources.
B) coevolving.
C) increasing niche overlap.
D) involved in succession.

6) Which of the following is NOT likely to characterize pioneer plant species involved in primary succession?
A) produces many small seeds that can travel great distances
B) slow-growing, long-lived perennial
C) able to tolerate low nutrient levels
D) able to tolerate intense sunlight
E) small size

7) In the process called __________ , predator and prey species act as agents of natural selection on each other.
A) commensalism
B) coevolution
C) succession
D) competition
E) symbiosis

8) Phosphorus, which is very commonly a limiting nutrient in ecosystems, is very important because it
A) evaporates quickly.
B) is found only in sedimentary rocks.
C) is part of the hydrologic cycle.
D) is necessary for the production of cellulose so that autotrophs can grow and provide food for heterotrophs.
E) is needed for molecules such as ATP, cell membranes and nucleic acids.

9) Which best illustrates the movement of energy through an ecosystem?
A) food web
B) trophic chain
C) nutrient cycles
D) biological magnification
E) food chain

10) Which of the following factors is (are) frequently limiting in terrestrial environments?
A) water
B) oxygen and nutrients
C) both water and appropriate temperatures
D) appropriate temperatures
E) nitrogen gas

11) Which of the following is NOT a characteristic of a tropical rainforest?
A) high temperatures
B) very high species diversity
C) arboreal animals
D) vegetation grows in layers
E) fertile soil

12) When succession occurs after a field is abandoned in the southeastern U.S., the rich soil and intense sunlight initially allow fast-growing annual species such as __________ to thrive.
A) ragweed and crabgrass
B) tulip poplars and sweetgum
C) oaks and maples
D) mosses
E) pine trees

13) If a wolf eats a rodent that ate a smaller insect that ate a plant, the wolf would be a(n)
A) primary producer.
B) tertiary consumer.
C) secondary consumer.
D) primary consumer.
E) autotroph.

14) Eutrophic lakes have
A) very little productivity.
B) clear water.
C) few phytoplankton.
D) high nutrient levels.
E) high oxygen concentrations in deep water.

15) An important density-independent factor limiting population size is __________.
A) weather
B) competition
C) predation
D) food quantity
E) environmental resistance

16) Over the past century, sagebrush has dramatically expanded its range over the Colorado Plateau's grasslands. This has been attributed to the overgrazing of the area's grasses by cattle and sheep. This ex indicates that
A) grazing has no effect on the distribution of plants.
B) the relationship between sagebrush and grasses is mutualistic.
C) sagebrush is the dominant competitor over grasses.
D) the range of sagebrush is normally limited by competition with grasses.
E) sagebrush could not exist anywhere in the absence of cattle and sheep.