Exam 2: Ecology

Which statement best describes the flow of energy through a pyramid.

• 90% of the energy available in the producers is available for the herbivores

• 10% of the energy available in in the producers is available for the herbivores, and the rest is lost as heat

• All of the energy available in the producers is passed to the herbivores

• There is no energy in an energy pyramid.

E. coli bacteria in a human’s small intestine serves to complete the digestion of food so the human can absorb the nutrients. In turn, the human supplies the E. coli a place to live and energy. Which term best describes the type of relationship between the human and E. coli?

• Parasitism

• Mutualism

• Commensalism

• Predation

Plants use nitrogen to make proteins. What is present in the soil that makes nitrogen directly available to plants through nitrogen fixation?

• air

• water

• bacteria

• sugar

Which of the following is a biotic factor that affects population size.

• Number and kinds of predators

• Weather

• Temperature

• Soil

Carbon is the basis of all life and is constantly being cycled through ecosystems. In which form is carbon passed along from animals to plants?

• carbon dioxide

• fossil fuels

• greenhouse affect

Why is the relationship between a dog and a flea considered parasitic?

• The dog is neither harmed nor helped.

• The dog is harmed while the flea is benefiting.

• The flea is neither harmed nor helped.

• This is not a parasitic relationship.

What trophic level is the mouse a part of?

• producer

• herbivore

• secondary (2nd) consumer

• tertiary (3rd) consumer

In the water cycle: ________ is the process by which water changes from a liquid to a gas

• precipitation

• condensation

• evaporation

• nitrogen fixation

__________ is NOT found in the atmosphere on Earth.

• Nitrogen

• Phosphorous

• Oxygen

• Carbon

Heterotrophs are also called ____________

• Producers

• Consumers

• Autotrophs