Nitrogen Cycle Questions

1) Which of the following chemical formulas represents the Nitrogen in the atmosphere?

• NH4
• NO3
• NO4
• N2
• N2O4

2) What living organisms play an important role in helping Nitrogen change states in the soil?

• Bacteria
• Option 1
• Reptiles
• Algae
• Mammals

3) Which process in the nitrogen cycle turns dead plants and animals into ammonium?

• Fixation
• Nitrification
• Assimilation
• Ammonification
• Denitrification

4) Which process in the nitrogen cycle turns ammonium into nitrates?

• Fixation
• Nitrification
• Assimilation
• Ammonification
• Denitrification

5) Which process in the nitrogen cycle takes extra nitrogen from the soil and puts it back into the air?

• Fixation
• Nitrification
• Assimilation
• Ammonification
• Denitrification

6) Which process in the nitrogen cycle turns nitrogen into ammonium?

• Fixation
• Nitrification
• Assimilation
• Ammonification
• Denitrification

7) Which process in the nitrogen cycle occurs when plants absorb nitrogen from nitrates in the soil?

• Fixation
• Nitrification
• Assimilation
• Ammonification
• Denitrification

8) In what way is nitrogen important to life on Earth?

• It is used in making DNA
• It is used to make chlorophyll in plants
• It is used in amino acids and proteins
• All of the above
• None of the Above

9) True or False: Human activities such as nitrogen fertilizer can upset the balance of the nitrogen cycle

• True
• False

10) Around what percentage of the Earth's atmosphere is nitrogen?

• 2%
• 14%
• 30%
• 49%
• 78%