NUTRIENTS CYCLE

Question 1

Eutrophication

Answer 1

1. Nitrates washed away into water
2. Causes rapid growth of algal bloom
3. Algae bloom block light so less respiration
   4.Algae die
4. Plants cant photosynthesis under water die off
5. Large increase of saprobiaonts
6. Respiration eate increases
7. Bacetria reduces o2 concentration of water
8. O2 level decreases causes death lf other aerobic organisms
9. Increase in anaeribic respiratiom = releases toxins causes putrid conditions

Question 2

Role of mycorrhizae

Answer 2

Fungi colonize roots system of plant
Increases area for the fungu to fix nitriten gas
Plamts provide the fungus with carbohydrates formed in ohotisynthesis

Question 3

Enviromental impact using fertilisers

Answer 3

Reduces species diversity
Crops removed = less demposition = kess nitrate is returned to the soil
Leaching

Question 4

Phoshorous cycle

Answer 4

1. Phospholipids , RNA , DNA from dead organisms decomposed by saprobionts into phospahe ions
2. Phosphate ions found in waste and rwmains ( bones/shells)
3. Phosphate ions transported by streams m river and icen from sedimentary rocks
   4.erosion of rocks helps phosphate ions dissolve in oceans , lakes, soils
4. Phospahte become available for absorption by plants for biomass by active transport

Question 5

Describe how the action of microorganisms in the soil produces a source of nitrates for crop plants

Answer 5

1. Saprobionts converts DNA/proteins/ amino acids into ammonium compound
2. Ammonium into nitrite
   3, nitrtite into nitrate by nitrifying bacteria
3. Nitrigen gas to ammonium by nutrigen-fixing bacteria in soil

Question 6

Nutriten cycle

Answer 6

Ammonification: saprobionats break down DNA, RNA NAD into ammonia Secreting extracellular enzyme
Nitrification: ammonia is oxidised to nitrites then nitrates by nitrifying bacteria
Denitrification: nitrates converted to N2 has by denytrifying bacteria ( anaerobic condition)
Nitrogen fixation: reduce N2 has to ammonium ions