Chapter 23 (Ecosystems)

Question 1

What are the main named bacteria involved in the nitrogen cycle?

Answer 1

1a) Azotobacter- Lives in soil, creates ammonia using nitrogenase enzyme

1b) Rhizobium- Live in root modules, creates ammonia

2a) Nitrosomonas- oxidises ammonium compounds into nitrites (NO2-)

2b) Nitrobacter- oxidises nitrites into nitrates (NO3-)

Question 2

What are the main stages of the nitrogen cycle?

Answer 2

1) Nitrogen fixation
2) Nitrification
3) Denitrification
4) Ammonification

Question 3

What is an ecosystem?

Answer 3

All of the living organisms that interact with each other in a defined area, as well as the physical factors