Quiz: Human Impacts on the Nitrogen Cycle

1. Nitrogen fertilizer is often added to soil to increase the growth of crops. Which of these nearby ecosystems would most likely be harmed by the use of nitrogen fertilizer?

A.  Forest

B.  Pond

C.  Park

D.  Meadow

2. Nitrogen waste washing into a pond would most likely cause an increase in __ .

A fish reproduction

B flooding

C water plant growth

D evaporation

3. The diagram to the right shows a simplified

nitrogen cycle in a freshwater aquarium.

What would probably happen if additional fish

were added to the aquarium?

A Nitrite levels would decrease.

B Nitrate levels would increase.

C Bacterial populations would decrease.

D Fish size would increase.

4. Heavy rains in an aquifer’s recharge zone cause rivers and streams to flood. How will this most likely affect the aquifer?

A The total water volume will increase.

B The outflow from natural springs will decrease.

C The water level in the aquifer will decrease.

D The rate of water use by humans will increase.

5. Planting additional legumes in the area shown above would most likely lead to which of the following?

A A decrease in the activity of bacteria

B A decrease in the number of animals in the area

C An increase in the activity of nitrogen-fixing bacteria

D An increase in the number of species that can fix nitrogen