Cycles

Question 1

Examples of nitrogen containing molecules in plants

Answer 1

RNA
DNA
mRNA
NAD
NADH
Amino acids

Question 2

Nitrification

Microorganism and reaction

Answer 2

Nitrifying bacteria
Ammonia oxidised to nitrates
Nitrites to nitrates

Question 3

Denitrification

Microorganism and reaction

Answer 3

Denitrifying bacteria
Convert nitrate to nitrogen gas in waterlogged anaerobic conditions

Question 4

Nitrogen fixation

Microorganism and reaction

Answer 4

Nitrogen fixing bacteria
Nitrogen gas reduced ammonia

Question 5

Decomposition

Microorganism and reaction

Answer 5

Saprobionts Bacteria
Convert nitrogen containing compounds to ammonia

Question 6

Order of bacteria nitrogen cycle

Answer 6

1. Saprobionts
2. Nitrifying bacteria
3. Denitrifying bacteria
4. Nitrogen fixation

Question 7

Phosphorus cycle

Answer 7

1. Phospholipids., RNA and DNA from Doug dead organisms into phosphate ions.
2. Decompose by.Saprobionts
3. Phosphate ions also found in waste and remains.
4. Phosphate ions transported by streams of rivers, lakes and oceans.
5. Form a sedimentary rock.
6. Weathering and erosion of rock rock helps phosphate ions dissolve in ocean lakes and soils
7. Phosphate become available for absorption by plants to incorporate into biomass

Question 8

Describe how mycorrhizae and plants both have a mutualistic relationship

Answer 8

Mycorrhizae benefit plants by increasing total surface area of plant root, increase of absorption of water and mineral ions. Plants benefit by producing organic molecules so mycorrhizae can respire

Question 9

What are fertilisers?

Answer 9

Increase growth rate of plants
2 types of fertilisers:
Natural = waste material such as manure
Artificial = manufactured powders containing nitrates and phosphates

Question 10

Environmental impact of using fertilisers

Answer 10

1. Reduces species diversity.= plants which are adapted to so high nitrate concentrations out compete other species.
2. Environmental issues.= removed crops.
   3.Leaching = more ions are applied than taken in which leads to leaching and the ions dissolved in soil water and washed away from soil into streams lakes and rivers which causes eutrophication

Question 11

Eutrophication

Answer 11

1. Nitrates washed up into water courses and buildup.
2. High concentration of ions lead to rapid growth of algae
3. Algae blocks sunlight which means less photosynthesis.
4. Algae die
   5, plants can’t photosynthesise under the surface also die
5. Increase in Saprobionts bacteria which convert nitro containing compounds into ammonia,
6. Increase in respiration rate.
7. Reduce oxygen concentration of water
8. Oxygen levels depleted, resulting in death of aerobic organisms.
9. Increasing anaerobic respiration lead to release of toxins.= putrid conditions