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2014-05-17 05:08:12
Biology Productivity camturnbull

AQA BIOL4 Energy flow
Show Answers:

  1. What is primary productivity?
    The amount of energy converted from light energy into chemical energy in 1 m2 over a year in kJ/m2/year
  2. What is an alternate measurement for primary production?
    Amount of new plant biomass in 1m2 in one day measured in g/m2/day
  3. What is the GPP?
    The gross primary productivity: the rate at which the products of photosynthesis accumulate
  4. What is the NPP?
    • The net primary productivity: the amount of biomass available as food 
    • Plants use some of the products of their photosynthesis for respiration
  5. Write a word equation for Net primary productivity
    NPP = GPP - respiratory loss
  6. Name 5 biotic and abiotic factors that affect productivity
    • Light intensity
    • Availability of minerals 
    • Competition from other species 
    • Damage by pests 
    • Water availability
  7. What is the energy input for a natural ecosystem?
    Solar energy
  8. What is the energy input for a farm ecosystem?
    • Solar energy
    • Chemical energy as food for workers
    • Fossil fuels for machinery
  9. Describe the productivity of a natural ecosystem
    • Low due to: 
    • Higher rates of competition
    • Increased damage by pests
    • Reduced availability of minerals
  10. Describe the productivity of a farm ecosystem
    • High due to:
    • Pesticides removing competition and pests
    • Fertilisers increasing the availability of minerals