1. Cycles & the Effects of Humans
Effects of Agriculture
The Loss of Biodiversity
Impact of Global Warming
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2. Effects of Agriculture
A. The Nitrogen Cycle
B. Use of Fertilizers
C. Dangers of Pesticides
Everything and more

3. A. The Nitrogen Cycle 1. The nitrogen cycle involves:
a. N2 cannot be used by plants or animals, they rely on soil nitrates
b. nitrogen fixation (production of nitrates) can be carried out by some bacteria, lightning, or the Haber process_
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4. c. bacteria convert protein to ammonium or nitrate
d. denitrification converts nitrates back to N2 _
Anoxkaldnes
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5. Think about it! B. Use of Fertilisers
What are some benefits to the current methods used in farming?
Think about it!
B. Use of Fertilisers
1. Farmers may use fertilisers containing nitrogen to make proteins (enzymes)
a. replaces minerals washed away by rain
b. help crops grow faster and larger
c. get higher yields of produce_
Producepedia
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Think

6. a. eutrophication- algal bloom depletes water of oxygen
2. Leaching (run off) of excess nitrogen fertilisers may damage aquatic ecosystems
a. eutrophication- algal bloom depletes water of oxygen
b. kills plants and increases bacteria
c. may release toxins_
Wikimedia Commons
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7. 3. Organic fertilisers are an alternative to the use of nitrogen fertilisers_
Stuartmill Farm
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8. C. Dangers of Pesticides
1. Farmers may need to use pesticides to control pests
a. insects eat leaves of crops
b. fungus rots produce
c. pesticides prevent crops from being eaten or decayed
d. increases yields from crops_
flickr
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9. 2. Using pesticides that kill many different kinds of organisms may endanger other living organisms
a. condor
b. grebe_
Squidoo
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10. 3. The use of DDT to kill mosquitoes leads to biological magnification
a. amplified as it passed through food chains
b. living matter is used for raw materials or burned
c. pesticide remains concentrated in the tissues_
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11. 4. There are alternative methods of pest control
a. biological control using predators of the pest (ladybug eats aphids)
b. genetically modified plants_
flickr
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12. The End

13. The Loss of Biodiversity
A. The Water Cycle
B. Acid Rain
C. The Point of Extinction
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14. A. Water Cycle 1. The water cycle involves:
a. water evaporates from land (soil and trees) and water bodies
b. water vapour condenses as it goes into the atmosphere
c. water falls from clouds as rain, hail, or snow (precipitation)
d. runoff creates ponds, lakes, and aquifers_
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15. 2. Deforestation can cause soil erosion and flooding
a. lack of trees reduces
1) windbreak leading to erosion of soil
2) evaporation through transpiration_
Encyclopedia Brittanica
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16. b. water not absorbed by roots creates excessive runoff
c. running water carries soil and nutrients away
d. overloads rivers and lakes causing flooding_
New Your Times
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17. B. Acid Rain 1. Sulphur dioxide is produced by burning fossil fuels
a. sulfer dioxide + water  sulfuric acid (acid rain)_
Wheresmyamerica
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18. a. low pH damages photosynthetic tissue of trees
2. Acid rain produced from sulphur dioxide has devastating effects on living organisms
a. low pH damages photosynthetic tissue of trees
b. washes essential minerals out of soil
c. inhibits decomposition
d. washes aluminum (toxic) into rivers and lakes_
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19. C. The Point of Extinction
What are some endangered species you have heard of?
Think about it!
C. The Point of Extinction
1. Current estimates indicate we may now be losing one plant and one animal species every 30 minutes
a. giant pandas, tigers, polar bears, whales and dolphins, rhinos, elephants, marine turtles and great apes_
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Think
Web

20. a. reduce hunting as a source of pest control
2. Humans need to conserve endangered species and their natural habitats
a. reduce hunting as a source of pest control
b. prevent commercial exploitation by poachers
c. preservation, reclamation, and creation of lost habitats_
zap events
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21. The End

22. Impact of Global Warming
A. The Carbon Cycle
B. The Greenhouse Effect
C. Global Warming
Zastavki
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23. Think about it! A. The Carbon Cycle 1. The carbon cycle involves:
Explain how it is possible for carbon to go from one organism to another?
Think about it!
A. The Carbon Cycle
1. The carbon cycle involves:
a. respiration by animals (and plants) produces carbon dioxide
b. photosynthesis by plants uses up carbon dioxide
c. carbon dioxide dissolves in water and settles
d. decomposition of dead organisms releases carbon dioxide_
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Think

24. e. fossilization or organic matter traps carbon in earth
f. burning fossil fuels produces carbon dioxide_
Health Hype
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25. B. The Greenhouse Effect
1. Greenhouse gases trap infrared radiation (heat) close to the Earth’s surface
a. increased as greenhouse gasses are raised
b. carbon dioxide due to combustion of fossil fuels
c. methane produced by ruminants (cows) and swamp gas
d. CFC’s from aerosols and refrigerants_
UNEP
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26. 2. Deforestation can also increase the amount of carbon dioxide in the atmosphere
a. removal of woodland reduces the amount of plants available to photosynthesize_
University of Georgia
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27. C. Global Warming
1. There are many ecological impacts that result from increased temperatures on earth
a. greater climate extremes- stronger winds, heavier rainfalls, and unseasonable weather_
Hurricane Disasters Live
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28. b. melting of polar ice changes density of sea water and raises sea levels_
Bird Holidays
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29. c. evaporation of water from fertile land forming deserts_
New Mexico State University
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30. d. disruption of delicate ecosystem balances and increased spread of pests_
Colorado Confidential
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31. The End