Topic 2 Plants: Nitrogen Fixation

Question 1

• Plants have a symbiotic relationship with nitrogen-fixing bacteria
• Bacteria fix atmospheric nitrogen into a usable form for plants; in return, plants produce food for bacteria via photosynthesis

Answer 1

Nitrogen fixation

Question 2

• In root nodules of legumes

- Fix atmospheric nitrogen (N2) to ammonia (NH3) and ammonium (NH4+)

Answer 2

1. Nitrogen fixing bacteria

Question 3

• Convert ammonia and ammonium to nitrites (NO2) and then to nitrates (NO3-)

Answer 3

2. Nitrifying Bacteria

Question 4

• Nitrates are taken up by plants (assimilation of nitrogen) and incorporated into amino acids and chlorophyll
• Animals (consumers) acquire nitrogen by eating plants (producers)

Answer 4

3. Nitrates

Question 5

• Of dead decaying plants and animals provides soil with nitrates

Answer 5

4. Detritus

Question 6

• Convert nitrates back to atmospheric nitrogen

Answer 6

5. Denitrifying Bacteria