Ch 3 Test Review

Which description of ecosystem organization is correct?

• communities, species, populations

• species, populations, communities

• species, communities, populations

• populations, species, communities

The total amount of living tissue in a given trophic level is called

• trophic mass

• organic mass

• biomass

• energy mass

The grass in this food chain represents

• heterotrophs

• decomposers

• producers

• primary consumers

The mushrooms in this food chain represent

• primary consumers

• decomposers

• producers

• autotrophs

How do most producers make their own food?

• using light energy to make carbohydrates

• using chemical energy to make carbohydrates

• changing water into carbon dioxide

• breaking down remains to make carbon dioxide

Animals get most of the nitrogen they need by

• consuming plants or animals

• breathing atmospheric nitrogen

• directly from bacteria in the soil

• denitrification

Which biotic factor can affect the size of a population?

• average temperature of an ecosystem

• type of soil in an ecosystem

• numbers & kinds of predators in an ecosystem

• concentration of oxygen in an ecosystem

Which is an example of how biotic & abiotic factors interact?

• sunlight increases the temperature of pond water

• water & soil mix to make mud

• tree roots split apart rocks in the ground

• humidity in the air forms fog in a valley

Which even is likely to add the MOST carbon dioxide into the atmosphere?

• a hurricane in the Gulf of Mexico

• clear-cutting trees in the rain forest

• leakage from a nuclear reactor

• eruption of a volcano

The mouse is a primary consumer. What evidence from the food web supports this claim?

• it feeds on producers

• it competes with carnivores for food

• it is prey for herbivores

• it is eaten by other organisms