Lesson 3.2 Test - Cycling of Matter

The carbon cycle makes carbon compounds continuously available in an ecosystem and delivers ________.

• water to all organisms

• light energy to autotrophs

• carbon dioxide to animals within the ecosystem

• chemical energy to organisms within the ecosystem

Fossil fuels are part of which of these cycles?

• carbon

• oxygen

• nitrogen

• phosphorus

What happens during the process of nitrogen fixation?

• Bacteria change ammonium into nitrate

• Bacteria grow on nodules on plant roots

• Bacteria convert gaseous nitrogen into ammonia

• Bacteria absorb ammonia and excrete ammonium

Bacteria are important in the nitrogen cycle because they ___________.

• produce sugars that plants can use

• decay and eventually form fossil fuels

• respire, returning carbon dioxide into the atmosphere

• help convert nitrogen into a form that organisms can use

Which process is part of the hydrologic cycle?

• nitrification

• transpiration

• sedimentation

• decomposition

Transpiration in trees is a part of which cycle?

• water cycle

• carbon cycle

• nitrogen cycle

• phosphorus cycle

What happens to phosphorus when animals die?

• returns to soil

• is dissolved in water

• evaporates into the atmosphere

• is decomposed by decomposers

This incomplete diagram shows carbon cycling through the atmosphere, biosphere, and geosphere. How should the diagram be completed in order to demonstrate the flow of carbon in the system?

• Arrow 2 should point toward the biosphere, and arrow 3 should point toward the atmosphere

• Arrow 2 should point toward the atmosphere, and arrow 3 should point toward the atmosphere

• Arrow 2 should point toward the biosphere, and arrow 3 should point toward people and animals.

• Arrow 2 should point toward the atmosphere, and arrow 3 should point toward people and animals

The area where the Mississippi River empties into the Gulf of Mexico contains little to no oxygen. This is caused by an excess of nutrients, including nitrogen, from various sources, such as agricultural runoff. Which activities could a farmer in this region do to help decrease the amount of nitrogen added into the Mississippi River?

• adding manure to the soil

• planting corn in a nitrogen-rich field

• adding nitrogen gas-releasing bacteria to soil

• adding commercial fertilizer to the soil

The diagram shows part of the carbon cycle. Which process adds carbon to the soil?

• dead organisms

• photosynthesis

• animal respiration

• mining of fossil fuels