Nitrogen Cycle

Which nitrogen cycle process is occurring when bacteria convert ammonium to nitrite and then into nitrate?

• nitrogen fixation

• nitrification

• denitrification

• ammonification

• assimilation

Which of these nitrogen cycle processes converts atmospheric nitrogen to a soil form of nitrogen that is usable by plants?

• nitrogen fixation

• nitrification

• denitrification

• ammonification

• assimilation

Organisms that break down dead plants & animals and release nitrogen back into atmosphere...

• bacteria
• plants
• animals
• producers

Organisms that need nitrogen to survive

• only plants
• only animals
• only bacteria
• all living organisms

If the atmosphere is 78% N₂, why can't we just get our nitrogen by breathing?

• It is hard to get out of the atmosphere

• Our lungs would be damaged by the N2.
• We need Oxygen for cellular respiration.
• The legumes take it up first.

Plants and animals cannot use nitrogen directly from the air.

• True
• False

After plants and animals contain nitrogen, what puts it back into atmosphere and soil?

• decomposition
• precipitation
• condensation
• bacteria

Nitrification happens in the ______

• Air 
• Soil 
• Ground Water 
• Plants 

What is the % of Nitrogen in the air?

• 21%

• 87%

• 78%

• 50%

Living organisms need Nitrogen to make which of the following?

• Glucose

• Proteins

  DNA

  chlorophyll

• Sunlight

• Ultraviolet Radiation