the environment

• Advantages of Intensive farming -

  • Increased yield of crops
  • High levels of meat production
  • More food produced to meet the growing population
  • Less land needed
• Disadvantages of Intensive farming -

  • pesticides could get into the human food chain and affect human health
  • battery methods - inhumane
  • destroys natural environment e.g removes hedgerows for larger use of land
  • Excess use of antibiotics in animals could be present in their meat - causes increased bacterial resistance
• Advantages of organic farming -

  • Pesticide free
  • Less damage to environment
  • Sustainable
  • Manure (instead of chemical fertilisers) - recycles waste and improves soil
• Disadvantages of Organic farming -

  • less yield
  • More labour intensive - makes food more expensive
  • Uses more land
• Bioaccumulation - often caused by heavy metals (industrial work)/ pesticides (farming)

  • Pesticides is persistent - does not break down
  • Pollutant washed into lakes/rivers
  • Absorbed by producers (roots uptake water)
  • pesticides build up inside animals from small to big (accumulates inside the food chain)
  • Reaches toxic levels (high concentration)in top carnivores
  • Causes death/ fertility problems/ health problems
• Intensive farming issues -

  • Kills insects which organisms higher up the food chain eat
  • After using pesticides, only resistant bugs remain to reproduces so pesticides stop working - stronger ones have to be used
• Bioaccumulation of heavy metals - Minimata Disease

  • lack of coordination
  • numb extremities
  • paralysis
  • insanity
• Why use fertilisers?

  • Increase crop yield

  Main 3 nutrients in fertiliser

  • Nitrates - NO − 3.
  • Phosphates - PO43-
  • Potassium - K+
• Eutrophication

  • Farmer sprays fertiliser onto crops to increase crop yield
  • When it rains - fertilizers containing nitrates leech to waterways
  • Water plants & algae on surface grow rapidly due to extra nitrates (algal bloom
  • Algae on surface block light to organisms below the surface
  • Plants below die due to lack of light ( no photosynthesis )
  • Bacteria decomposes dead plants and they rapidly increase and respire using up the remaining oxygen in the water
  • Fish die due to lack of oxygen
• Eutrophication with sewage

  • sewage enters rivers along with decomposers
  • these bacteria we oxygen supply for respiration
  • lack of oxygen for marina animals/plants
• A pollutant is something that has been added to the environment and which damages it in some way e.g SO2, sewage, heavy metals, oil.
• Indicator species = A living organism that indicates the amount of pollution in an area
• Clean, well oxygenated streams have a high biodiversity, a polluted stream will have a low number of species which have many adaptation to survive in lox oxygen concentrations
• Level of water pollution :

  Clean - mayfly nymph, stonefly nymph

  Low - freshwater shrimp, caddis larvae

  High - water louse

  Very high - rat tailed maggot , sludgeworm
• Lichens are a indicator species for air pollution

  Lichens are plants that occur as crusty patches on rock tree trunks and walls. They are sensitive to SO2 in the air
• Habitat is where an organism lives
• Community is where all living organisms in a habitat at the same time
• Ecosystem is where living and non living parts of a habitat and their interactions
• Producers are plants that make their own food by photosynthesis using light energy from the sun
• Consumer are organisms that eat other organisms for food
• Arrows in a food chain show energy transfer
• Food chains always seem to end with a large predator. What might feed on a large predator?


  parasites
• • Primary consumer can also be called herbivores - 2nd Trophic level, (they are prey to the 3rd TL)
  • Secondary consumer can also be called Carnivores - 3rd Trophic level, (they are prey to the Top predator)
  • Teritary consumer can also be called Carnivores - Apex/ Top predator

  A) producer

  B) primary consumer

  C) secondary consumer

  D) tertiary consumer

  
• Producers are green plants which photosynthesise. They use light energy from the sun to convert carbon dioxide from the air and water from the soil into glucose and oxygen. The glucose made can be eaten by other organisms so that they can use it for respiration which releases the energy stored in the glucose. This energy can then be used for their life processes.
• • Producer - Using light energy to produce food by photosynthesis
  • Primary consumer - Eating producers, most are herbivores
  • Herbivore - Eating only plants
  • Secondary consumer - Eating primary consumers, most are carnivores
  • Carnivore - Eating only other animals
  • Tertiary consumer - Eating secondary consumers
  • Omnivore - Consumers which eat both animals and plants, so can occupy more than one trophic level in a food chain
  • Decomposer - Feeding on dead and decaying organisms, and on the undigested parts of plant and animal matter in faeces
• Pyramid of numbers - size of the box represents the number of organisms present at each feeding or trophic level. Sometimes a pyramid of numbers does not look like a pyramid at all. These are known as inverted pyramids. This could happen if the producer is a large plant, such as a tree, or if one of the animals is very small. Here are two examples.

  
• Pyramid of biomass - The total dry mass of living material at each feeding level in a food chain, in a pyramid of biomass each box represent the total mass of all the organisms present at each level

  
• Energy source for almost all food chains are sunlight
• The plants at the beginning of the food chain are able to capture only 1% of the energy from the sunlight. The transfer of this energy from one feeding level to the next is very inefficient. On average only 10% of the energy from the previous level becomes available to the next as chemical energy stored in new body tissues
• Light energy from the sunlight is transformed into chemical energy, as glucose in plants
• Respiration releases the energy in glucose available for all living things to do work - to drive life activities
• Pollution may be blown in wind in one direction and will also travel downstream
• Pyramid of biomass -

  total mass of organisms at each level x number of individual mass
• Pyramid of number IS NOT ALWAYS a pyramid shape but a pyramid of biomass ALWAYS IS
• There is only 4/5 levels in a food chain because there wouldn't be enough energy left to support another organism
• Plants are responsible for catching the solar energy from photosynthesis.

  Some of that energy is used to make plant cells

  Plants use the sun to make glucose and cells
• All organisms use respiration to release energy from their food
• On average only 10% of the previous level of energy becomes available to the next and chemical energy becomes stored in the new body's tissues
• Organisms use the 10% of energy for

  • growth
  • repair
  • replacement of tissues
  • used to maintain body temp (warm blooded animals only)

  However it is lost in

  • lost in organisms waste materials (excretion)
  • producing heat
  • movement
• Efficiency = (Energy in later stage ÷ Energy in earlier stage) x100

  • Less energy is transferred at each level of the food chain so the biomass gets smaller.