Nitrogen cycle

Question 1

What are nutrient cycles

Answer 1

biogeochemical cycles involving essential elements to life

Question 2

How much of the atmosphere is nitrogen

Answer 2

78%

Question 3

how do animals take up nitrogen

Answer 3

eating plants

Question 4

how are nitrate concentration replenished

Answer 4

decomposed animals and plants replenish the soil as there are very few nitrate ions from other sources

Question 5

First stage nitrogen cycle

Answer 5

nitrogen fixation- nitrogenase enzyme catalyses N2 to ammonia NH3 by a bacteria Rhizobium , the bacteria and plants have a mutually beneficial relationship- bacteria provide the plants with nitrogen containing compounds and plants provide carbohydrates

Question 6

Second stage of nitrogen cycle

Answer 6

ammonification- sabprobionts such as fungi decompose the tissue of a dead organism and release inorganic nitrogen into the ecosystem as ammonia

Question 7

third stage of nitrogen cycle

Answer 7

Nitrification- Ammonia oxidised into nitrate and nitrite by nitrifying bacteria

Question 8

fourth stage of nitrogen cycle

Answer 8

Denitrification- Denitrifying bacteria use nitrates in the soil during respiration. This process produces nitrogen gas, which returns to the atmosphere. This process occurs in anaerobic conditions (when there is little or no oxygen available, such as in waterlogged soil)