The Organism in the Environment

• what is an ecosystem?

  all the biotic factors and all the abiotic factors that interact within an area at one time
• what is a habitat?

  the place an organism lives
• what is a population?

  all the organisms of one species in a habitat
• what is a community?

  all the different species in a habitat
• what is a biotic factor?

  a living factor
• what is an abiotic factor?

  a non-living factor
• what is biodiversity?

  a measure of the variety of different species in an ecosystem
• is a rainforest an example of high or low biodiversity?

  high
• why is biodiversity importance?

  reduces the dependence of one species on another
• how can you use a quadrat to investigate population size?

  randomly place a quadrat

  count

  repeat 10 times and take an average

  multiply by total
• what are some abiotic factors that affect population size?

  temperature

  pH

  light
• what are some biotic factors that affect population sizes?

  predation

  competition

  disease
• how does the carbon cycle work?

  respiration

  photosynthesis

  decomposition

  combustion
• how does the nitrogen cycle work?

  nitrogen fixing

  absorption by plants

  movement along food chain - animal dies

  ammonia turned into nitrites and then nitrates by nitrifying bacteria

  denitrification
• why is sulfur dioxide bad?


  dissolves in rainwater to form acid rain

  kills marine life and plants
• why is carbon monoxide bad?

  binds to the haemoglobin

  less oxygen in the blood
• what do CFCs do?

  destroys ozone layer
• what are examples of greenhouse gases?


  carbon dioxide

  methane

  water vapour

  CFCs

  nitrous oxide
• what are some human activities that contribute to greenhouse gases?

  burning of fossil fuels

  deforestation
• what are the effects of deforestation?


  soil erosion

  leeching

  disrupts balance of gases in the atmosphere