1. Which ecological principle does an energy pyramid represent?
A. Large amounts of energy are lost in the transfer between trophic levels.
B. The ultimate source of energy in the biosphere is the sun.
C. Consumer organisms are more important than producer organisms.
D. Most producer organisms use photosynthesis to create organic compounds.

2. Which of the following is a density-dependent limiting factor on the Florida manatee population?
A. hot ocean waters
B. cold stress
C. bacteria
D. water salinity

3. Which is not a major biogeochemical cycle?
A. oxygen cycle
B. biosphere cycle
C. nitrogen cycle
D. carbon cycle

4. Which parameter of the hydrosphere does not change?
A. temperature vs. depth at low latitudes
B. density vs. depth at low latitudes
C. surface temperatures from low to high latitudes
D. temperature vs. depth at high latitudes

5. What does the phrase trophic level mean?
A. number of organisms at each stage in the food chain
B. level on the food chain
C. complex relationships that form food webs from various food chains
D. which species any given predator preys on

6. What did environmental scientists learn about succession from observing the Mount Saint Helens eruptions of 1980?
A.Only invading species from outside the disturbed area participate in succession.
B. Succession involves both biological legacies and invading species.
C. Succession theory predicted exactly how Mount Saint Helens would recover.
D. Succession is a steady progression that, once started, goes to a predictable conclusion.

7. Which strategy would have the least positive impact on life expectancy?
A. mechanizing agriculture
B. vaccinating against childhood illnesses
C. replacing hunting and gathering with agriculture
D. removing sanitation facilities

8. Which process is the fastest at releasing oxygen into the atmosphere?
A. aerobic respiration
B. weathering
C. photosynthesis
D. decay

9. What type of population growth is affected by carrying capacity?
A. logarithmic growth
B. exponential growth
C. logistic growth
D. linear growth

10. Distribution of thermal energy across latitudes involves interaction between the hydrosphere and what other sphere?
A. biosphere
B. cryosphere
C. atmosphere
D.geosphere

11. Which is an ex of a population migrating in response to environmental stress?
A. A polar bear needs a wide territory to find sufficient prey.
B. Bats sleep during the day and fly from their shelters at night.
C. A cactus species distribution changes over time when the average temperature in its former habitat becomes too high.
D. Honeybees pollinate bluebonnet flowers, helping the bluebonnets thrive in their native environment.

12. What does primary productivity measure?
A. rate of loss of energy in an ecosystem
B. number of organisms in an ecosystem
C. weight of all organisms in an ecosystem
D. rate at which an ecosystem produces chemical energy from sunlight

13. What is an ecosystem?
A. group of interacting populations in a defined place and the nonliving factors that affect them
B. all the animal and plant species within a geographical area
C. classification for a broad type of habitat, such as savanna or tropical forest
D. all the members of one species living in one place and time