The nitrogen cycle

Question 1

What are the processes involved in the nitrogen cycle?

Answer 1

Consumption, decomposition, nitrogen, fixing, nitrification and denitrification

Question 2

Nitrogen fixing

Answer 2

-Nitrogen in the air is converted into nitrates in the soil
-nitrogen fixing bacteria plants take up nitrates through their roots
-Some plants (legumes -peas,beans) have root nodules that contain bacteria (rhizobium)
- they convert nitrogen in the air (N2) to nitrates that plants can use directly -mutualism
-lightning can convert nitrites in the air into nitrates.
-This is similar to the other process which produces ammonia for fertiliser

Question 3

Nitrification

Answer 3

-Ammonia is converted into nitrites, and then nitrates
-Nitrifying bacteria carries out this process

Question 4

Denitrification

Answer 4

-Nitrates are converted into nitrogen gas
-Dentrifying bacteria carry out this process

Question 5

Name a compound that could be classified as organic nitrogen

Answer 5

proteins and DNA

Question 6

Suggest a source of organic nitrogen

Answer 6

Dead plants/animals/dung