13.3 nutrient cycles

Question 1

which process and how are organic compounds converted into ammonium ions (NH4+)?

Answer 1

saprobionts feed on faeces & dead organic matter

Question 2

which process and how are NH4+ converted into NO2- then NO3-?

Answer 2

nitrification
- oxidation that releases energy by nitrifying bacteria that carry out aerobic respiration

Question 3

what converted NO3- to N2 and what is the process called?

Answer 3

denitification
- denitifying bacteria carries out anaerobic respiration in waterlogged soil

Question 4

what is the process when NO3- is back in producers?

Answer 4

absorption

Question 5

what is the process and how is N2 back in producers?

Answer 5

nitrogen fixation
- free-living nitrogen fixing bacteria reduces N2(g) -> NH3
- mutualistic nitrogen-fixing bacteria lives on nodules on roots of plants which provide amino acids

Question 6

which 3 examples of plants have nodules on roots?

Answer 6

clovers, peas, beans

Question 7

how does PO4 3- ions go to and from rocks?

Answer 7

erosion / use of fertilisers
sedimentation

Question 8

how does dissolved phosphate ions go from oceans to plants?

Answer 8

absorption

Question 9

how does phosphate ions go from plants to animals?

Answer 9

digestion & feeding

Question 10

how does phosphate ions go from animals to wastes?

Answer 10

excretion & decomposition

Question 11

how does phosphate ions go from wastes to rocks?

Answer 11

deposition

Question 12

how does phosphate ions go from wastes to oceans?

Answer 12

erosion

Question 13

how does phosphate ions go from animals to oceans?

Answer 13

excretion