GCSE AQA Biology 3 Food Production

GCSE AQA Biology 3 Food Production

1. Efficiency of food production can be improved by:

   • Reducing the number of stages in the food chain
     • Less energy/biomass as you move up food chain
       • For area of land - can produce more food more humans by growing crops rather than having grazing animals
         • People do need varied diet (demand for meat) & some land is unsuitable for growing crops
   • Restricting energy lost by farm animals
     • Animals often intensively farmed - kept close together indoors in small pens, they're warm & can't move about
       • Saves them wasting energy on movement & stops them giving out energy as heat - makes transfer of energy from feed to animal more efficient
         • Makes things cheaper for farmer & consumer
   • Developing new food sources like mycoprotein
     • Mycoprotein: Protein from fungi (Fusarium is main source) - used to make meat substitutes for veg meals
       • Grown in fermenters, using glucose syrup as food (obtained by digesting maize starch with enzymes)
         • Fungus respires aerobically - with nitrogen (as ammonia)
           • Important to prevent other microorganisms growing - fermenter initially sterilised, incoming nutrients heat sterilised & air supply is filtered
             • Mycoprotein harvested & purified
     • Good in developing countries

2. Problems with efficient food production

   • Some people think forcing animals to live in unnatural/uncomfortable conditions is cruel (growing demand for organic meat)
   • Crowded conditions create favourable environment for spread of diseases
   • To prevent disease - animals are given antibiotics
     • When animals are eaten, antibiotics enter humans - allows microbes that infect humans to develop immunity
   • Animals need to be kept warm - using power from fossil fuels
   • Fish stocks are getting low but fish continues to feed animals that are intensively farmed

3. Food distribution causes problems

   • Some foods have lots of 'food miles' - transported a long way
     • Can be expensive & bad for environment

4. Overfishing is decreasing fish stocks

   • Less fish for us to eat
   • Need to maintain fish stocks at level where they continue to breed (sustainable food production)
     • Can do this by:
       • Fishing quotas - limits on number & size of fish (prevents certain species being overfished)
       • Net size - different limits on mesh size of fish net (reduce no. of unwanted fish - help them escape)