Ecology and Biogeochemical Cycles Assessment

Which biogeochemical cycle represents the movement of carbon through Earth's systems?

• Nitrogen cycle

• Carbon cycle

• Phosphorus cycle

• Water cycle

What is the primary source of energy in most ecosystems?

• Decomposers

• The Sun

• Consumers

• Minerals

In a food chain, what percentage of energy is typically transferred from one trophic level to the next?

• 90%

• 50%

• 10%

• 1%

What is carrying capacity?

• The maximum population size an environment can support

• The minimum number of organisms needed for survival

• The rate at which organisms reproduce

• The amount of food available in an ecosystem

Which of the following is a density-dependent limiting factor?

• Temperature

• Natural disasters

• Competition for resources

• Drought

What type of succession occurs on bare rock where no soil exists?

• Secondary succession

• Primary succession

• Tertiary succession

• Climax succession

Which organisms convert nitrogen gas into a usable form for plants?

• Decomposers

• Nitrogen-fixing bacteria

• Consumers

• Producers

In a food web, what term describes an organism that eats both plants and animals?

• Producer

• Decomposer

• Omnivore

• Herbivore

What is the term for all the populations of different species living in the same area?

• Community

• Population

• Ecosystem

• Biosphere

Which factor would NOT affect population density?

• Disease

• Food availability

• The color of organisms

• Predation