nitrogen cycle

Question 1

how does nitrogen leave the atmosphere

Answer 1

oxidized by lightening to form nitrates, nitrogen fixation to form ammonia

Question 2

what organisms influence the nitrogen cycle

Answer 2

bacteria involved in every step = nitrogen can be a limiting factor in plant growth

Question 3

how do humans impact the nitrogen cycle

Answer 3

add NO to atmosphere when burning fuel, slash and burn relseases nitrogen into atmosphere, excess nitrates from agricultural runoff into water sources, nitrogen removed from topsoil when crops harvested, inorganic fertilizers add nitrates

Question 4

consequences of human affects on nitrogen cycle

Answer 4

acid deposition, climate change, photochemical smog, deforestation/increasing soil erosion, loss of soil nutrients, increase in hypoxic zones in water, possible loss of biodiversity

Question 5

nitrogen fixation

Answer 5

N2 in the atmosphere is fixed by bacteria into ammonia, lightning oxidizes nitrogen into ammonia

Question 6

nitrification

Answer 6

ammonia is nitrified by bacteria nitrite, which is nitrified into nitrate

Question 7

assimilation

Answer 7

nitrate is absorbed into plants, which is absorbed by animals from plants

Question 8

ammonification

Answer 8

ammonium from animal waste and decomposed organic matter are nitrified into nitrites

Question 9

denitrification

Answer 9

denitrifying bacteria turns nitrate into NO2 in the atmosphere