Nitrogen Cycle

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

• nitrogen fixation

• nitrification

• denitrification

• ammonification

• assimilation

Tags

NGSS.MS-LS2-3

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

How much of the atmosphere is composed of nitrogen gas?

• 87%
• 38%
• 78%
• 21%

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

• bacteria
• plants
• animals
• producers

Tags

NGSS.MS-LS2-3

Organisms that need nitrogen to survive

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

Tags

NGSS.MS-LS2-3

NGSS.MS-LS2-1

Plants and animals cannot use nitrogen directly from the air.

• True
• False

Tags

NGSS.MS-LS2-3

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

• decomposition
• precipitation
• condensation
• bacteria

Tags

NGSS.MS-LS2-3

Nitrification happens in the ______

• Air 
• Soil 
• Ground Water 
• Plants 

Tags

NGSS.MS-LS2-3

NGSS.MS-LS2-4

Bacteria fix nitrogen on plant roots. Plant roots provide sugar to bacteria. This is an example of

• mutualism
• parasitism
• commensalism
• competition

Tags

NGSS.MS-LS2-2

How nitrogen is "fixed" into useable form for plants

• only through action of bacteria
• only through lightning
• through action of bacteria & lightning
• through photosynthesis