Flashcards
environmental consequences of using nitrogen fertilisers
Flashcards do conjunto (12)
- 1name three effects of nitrogen fertilisersreduced species diversity
leaching
eutrophication - 2how are fertilisers linked to reduced species diversity?nitrogen-rich soil favours the growth of one particular species. This species out-competes other species hence species diversity is decreased.
- 3What is meant by leaching?the process by which nutrients are removed from soil
- 4describe how leaching occursnitrates in the soil dissolve in water and drain into lakes and rivers
- 5what factors affect the rate/amount of leaching that occursamount of nitrates already in the soil
soil type and structure
the amount of rainfall
the amount of water used by crops and plants - 6What is meant by eutrophication?the process by which nitrate (nutrients) build up in bodies of water.
- 7describe the process of eutrophication1. nitrate concentration increases as a result of leaching
2. algae grow on the surface of the water = algal bloom
3. algae absorbs light hence preventing it from reaching deeper into the water.
4. photosynthetic plants die
5. saprobiotic organisms grow exponentially and demand for oxygen increases.
6.aerobic organisms die because oxygen concentration falls. - 8Explain how the leaching of nitrates from farmland into rivers may lead to a large increase in biochemical oxygen demand (BOD). (5 marks)nitrate limiting factor for plant growth;
increased growth of plants/algae/protoctists;
nitrate needed by plants for protein synthesis;
competition for light/effect of competition (e.g. plants underneath die);
plants die, providing food supply for microorganisms/number of
microbes increases;
use of oxygen for respiration of microorganisms - 9Suggest and explain how any other environmental factor could influence the rate of leaf decomposition. (2 marks)Soil water content;
water needed for hydrolysis - 10What is the difference between the ways in which microbial decomposers and detritivores obtain their nutrients? (2 marks)Decomposers secrete enzymes / onto organic matter/ food/
extracellular breakdown;
Detritivores ingest / eat/ take in organic matter/food first; - 11The radioactive phosphate was absorbed by the plant and incorporated into organic compounds. Name two phosphorus-containing organic compounds and describe their importance in plants. (4 marks)Phospholipid;
Part of cell membrane;
or
ATP/ADP;
ATP as source of energy for specific process;
ADP needed to produce ATP/needed in specific process;
or
Nucleic acids/DNA/RNA;
Carry genetic information/involved in protein synthesis; - 12Explain how each of the following could account for falling nitrate concentration. 1. algal growth 2.biological denitrification (2 marks each)1.Absorption / uptake by algae (not: ‘used’ or ‘used in growth);
Use in protein / amino acid synthesis.
2. Breakdown to nitrogen;
by denitrifying bacteria / named example, e.g. Pseudomonas.
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- a level Biology FlashCards sobre environmental consequences of using nitrogen fertilisers, criado por sferrier96 em 06-02-2015.
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