Nitrogen Cycle

Question 1

Nitrogen Fixation

Answer 1

Nitrogen from atmosphere into usable forms (ammonia NH3) or (ammonium NH4)
Bacteria in soil or root modules of legumes work this.
Lightning breaks nitrogen bonds and combines with oxygen and rain

Question 2

Nitrification

Answer 2

Converts ammonia and ammonium to nitrites (NO2-) then to nitrates (NO3-) plants then absorb
1. Ammonium —> Nitrites
2. Nitrites —> Nitrates

Question 3

Assimilation

Answer 3

Plants absorb nitrates through roots, and use to build proteins and DNA

Question 4

Ammonification

Answer 4

Decomposers break down dead organisms and waste, return nitrogen to soil as ammonia or ammonium.

Question 5

Denitrification

Answer 5

Nitrates back to Nitrogen gas.
Denitrifying bacteria do this (in low oxygen environments)