7.3

• What is biodiversity?

  The variety of the different species on earth or within an ecosystem.
• Why is biodiversity important?

  It maintains the stability of an ecosystem.
• How does biodiversity ensure the stability of an ecosystem?

  It reduces dependence on particular species for resources, allowing other species to survive if one is removed.
• What are the two main reasons for the increase in human consumption of resources and waste production?

  Rapid rise in human population and increase in standard of living.
• Where does pollution occur?

  • Air
  • Land
  • Water
• What are examples of water pollutants?

  • Sewage
  • Fertiliser
  • Chemicals
• How does eutrophication occur?

  Fertiliser from farms pollutes the water, causing excessive algae growth and depleting oxygen, leading to the death of other plants and animals.
• What are examples of air pollutants?

  • Smoke
  • Acidic gases
• What are examples of land pollutants?

  • Landfill waste
  • Chemicals
• Why have peat bogs been destroyed?

  To produce compost to increase food production.
• Which human activities reduce the land available for animals and plants?

  • Building
  • Farming
  • Quarrying
  • Disposing of waste
• Why does the destruction of peat bogs contribute to the greenhouse effect?

  Peat bogs are carbon sinks, and burning them releases large volumes of carbon dioxide into the atmosphere.
• Why have large-scale deforestation activities occurred?

  • To provide land for cattle or rice fields
  • To grow crops to produce biofuels
• What is causing global warming?

  The increase in levels of greenhouse gases such as carbon dioxide and methane.
• What is the greenhouse effect?

  Greenhouse gases trap energy from the Sun as heat in the atmosphere, keeping the temperature on earth suitable for life.
• What are the harmful effects of deforestation?

  • Destruction of many animals’ habitats
  • Releases large amounts of greenhouse gases
• What are the consequences of global warming?

  • Rising sea levels
  • Melting polar ice caps
  • Changing weather patterns
  • Migration of animals to find suitable habitats
  • Tropical diseases becoming more common
  • Extinction of species
• What is the purpose of replanting hedgerows and field margins?

  There is higher biodiversity in the margins than the fields that they surround.
• What steps are taken to maintain biodiversity?

  • Breeding programmes for endangered species
  • Protection and rebuilding habitats
  • Replanting field margins and hedgerows
  • Reduce deforestation
  • Reduce carbon dioxide emissions
  • Recycling rather than disposing in landfills