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B4 Energy Transfer

B4 Energy Transfer. Energy is Transferred through Ecosystems Energy enters ecosystems via photosynthesis . Energy is transferred through food chains and webs. The energy available determines the number/mass of organisms at each trophic level .

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B4 Energy Transfer

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  1. B4Energy Transfer

  2. Energy is Transferred through Ecosystems • Energy enters ecosystems via photosynthesis. • Energy is transferred through food chains and webs. • The energy available determines the number/mass of • organisms at each trophic level. • Humans manage/create food chains to maximise energy • transfer to humans. • This has environmental impacts.

  3. Photosynthesis is the main route by which energy enters an ecosystem photoautotroph chemoautotroph But not the only route – e.g. volcanic vents (extremophiles) http://www.youtube.com/watch?v=4LoiInUoRMQ

  4. Energy is transferred through food chains and webs tertiary consumer secondary consumers primary consumers producer

  5. What is the role of the decomposers? http://www.youtube.com/watch?v=XuKjBIBBAL8

  6. Why pyramids?

  7. Why is a BIOMASS pyramid always pyramid shaped?

  8. Pyramid of ………….?

  9. Energy pyramids

  10. Spot the exception to the rule. Possible explanation?

  11. What % is passed on each time? • Why? What happens to the energy?

  12. How much energy is available to be passed on to the next consumer? • %? • What happens to the 100J in the faeces?

  13. Why is it rare for there to be more than 5 trophic levels in a food web? http://www.youtube.com/watch?v=TE6wqG4nb3M&feature=related

  14. 6 degrees of separation………..

  15. Explain….. http://www.youtube.com/watch?v=zaysPpjGHy0&NR=1&feature=fvwp http://www.mcvideogame.com/why-eng.html

  16. How efficient is each transfer ? 2% 10% 10%

  17. Generally efficiency is about 2% from plants to animals and 10% from animal to animal. Why less from plant to animal than animal to animal? 22% 10%

  18. So if …….. • Carnivores are more efficient than herbivores (because cellulose/lignin difficult to digest) • and …… • Mammals are endothermic – so lose heat • and smallmammals lose relatively more heat (surface area:volume)

  19. Who is more efficient? Why? http://www.newvision.co.ug/D/9/37/753159

  20. Farming Livestock net productivity = gross productivity – respiration Therefore to max profits need to reduce losses due to respiration – how? http://www.youtube.com/watch?v=H4_R5sGHIGo

  21. Productivity

  22. Farming Crops • Fertiliser (artificial or natural) • Chemical pesticides or biological control to reduce pests on crops

  23. Environmental issues • Chemicals in food chain (DDT) • Eutrophication

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