Ecology

• Ecosystem


  Made up of communities of organisms that interact with their environment.
• Communities 


  Affected by biotic factors and abiotic factors.
• Abiotic factors

  Non living factors that interact with community and affect ecosystem.
• Examples of abiotic factors

  • Light intensity
  • temperature
  • moisture/water
  • pH
• Examples of biotic factors

  • availability of food
  • new predators
  • new pathogens
  • competition
• structural adaptations


  physical features e.g camouflage
• behavioural adaptations


  cause an organism to act/behave e.g migrate, cold conditions.
• Functional adaptations


  Affect the processes that occur inside an animals body. e.g produce venom
• Quadrats


  Square frames, divided into smaller segments
• Transects


  Used to distribution of organisms across an area.
• RQ- Measure population size and species distribution using sampling techniques.

  1. divide the area that is sampled, use random number generator to select cooridnates
  2. find each coordinate and place a quadratic on the ground
  3. count, record number of organisms of the species in quadrat
  4. repeat
  5. calculate the mean number of organisms per , squared
  6. calculate the population size
• mean number of organisms


  total number of organisms/ number of quadrats
• environmental change

  • temperature change
  • availability of water
  • composition of gases
• water cycle


  recycles all the water on the earth so organisms continue to receive the water they need to live.
• Water cycle

  1. water evaporated (turned into water vapour) used energy from the sun
  2. water also evaporates from plant leaves via transpiration
  3. water vapour carried upwards until cool and condenses into clouds
  4. water falls to ground aka rain
  5. water then drains into the sea via streams and rivers and process begins again
• carbon cycle


  allows carbon to move from organisms into the atmosphere so it can reabsorbed by plants.
• Carbon cycle process

  1. carbon dioxide taken in by photosynthesising plants, converted into glucose and other carbon compounds
  2. animals feed on plants, passing the along the carbon. Carbon pass all the way down the food chain.
  3. carbon released back into atmosphere in form of carbon dioxide when living organisms respire.
  4. carbon returns to environment via waste products.
  5. waste products get digested by microorganisms called decomposers.
  6. Remains compressed into fossil fuels.
  7. Fossil fuels are burnt (combustion)
• What do anaerobic decomposers produce?


  Methane
• RQ- investigating rate of decay by measuring pH changes

  1. 3 different water baths at different temperatures
  2. measure out 20cm cubed of milk into 3 different beakers
  3. Use universal indicator solution/paper or pH probe to measure pH of milk in each beaker.
  4. cover each beaker with cling film and place them in separate water baths.
  5. use universal indicator/ paper to check pH after 24, 48 and 72 hours. pH should decrease.
• What are bogs?


  Bogs are waterlogged and acidic areas of land
• Why humans destroy peat bogs?

  • are drained so the land can be used for farming
  • dried and burnt as fuel
  • used to make compost that farmers use to increase food production
• Impact of global warming:

  • habitats may be destroyed causing extinctions
  • food chains disrupted
  • organisms have to migrate due to extreme weather conditions
• Maintaining biodiversity

  • breeding programmes
  • protecting rare habitats
  • crop fields
  • waste recycled
• Trophic level 1


  Producers e.g green plants
• Trophic level 2 


  Primary consumers e.g herbivores
• Trophic level 3


  Secondary consumers e.g carnivores
• Trophic level 4 


  tertiary consumers e.g carnivores that each other carnivores
• Biomass lost:

  • consumers leave parts of the organism they are eating
  • consumers may not be able to absorb all biomass
  • organisms loose some material as waste products
• Efficiency of a biomass transfer

  is how much biomass is transferred to a consumer compared to how much is available.
• Biotechnology 


  Living organisms and processes to create products useful for humans.
• Production of human insulin


  bacteria can be genetically engineered to produce human insulin which is used to treat diabetes.