Classification and Biodiversity

• Two broad groups of plants

  • Flowering
  • Non-flowering
• Two broad groups of animals

  • Vertebrates
  • Invertebrates
• Vertebrates

  Have a backbone
• Invertebrates

  Do not have a backbone
• Scientific names for organisms are important so that there is no confusion and one universal name can be provided for each organism that everyone can understand
• Two ways organisms can be classified

  • Physical features
  • Phylogenetic relationships
• Adaptations

  Adaptations that mean organisms are more suited to their environment will help them to survive and reproduce as they will be able to outcompete other individuals
• Four things animals compete for

  • Mates
  • Space
  • Food
  • Water
• Four things plants compete for

  • Light
  • Water
  • Minerals
  • Space
• Two different types of competition in an ecosystem

  • Interspecific competition
  • Intraspecific competition
• Interspecific competition


  Where organisms of different species compete for resources (e.g. food, water, shelter)
• Intraspecific competition


  When organisms from the same species compete for resources (e.g. food, water, shelter)
• Competition is necessary when resources are limited and it leads to evolution by natural selection
• Biodiversity


  The variety of living organisms in an area
• Why biodiversity is important

  • Different organisms can provide food or useful industrial materials
  • Some animals or plants may have useful medicinal properties
  • Ecotourism benefits communities
• Convention on International Trade in Endangered Species (CITES)


  An international agreement that regulates the trade of endangered species so that their survival is not threatened and biodiversity can be maintained
• Conservation


  The sustainable and active management of an ecosystem
• Preservation


  Aims to maintain an ecosystem in its current state
• Site of Specific Scientific Interest (SSSI)


  An area of regulated and conserved land due to its natural features or the species it contains
• Captive breeding programmes


  Plans to help ensure the survival of a species by encouraging existing members of that species to breed together in enclosures (e.g. in zoos)
• Seed banks


  Store seeds in regulated environments to maintain copies of important genes in the seeds which can help to prevent extinction
• Quadrat


  A tool used to record the abundance of different plant species in a habitat
• It is important to take lots of readings in different areas when using quadrats so that the sample area is accurately represented
• The distribution of quadrats needs to be random to prevent biased results
• Transects


  Measure the change in the distribution of organisms in an area
• How to set up a transect

  1. Transects are lines that quadrats are placed along

  2. They are often long tape measures laid on the ground and quadrats are placed at regular intervals along them
• Mark-release-recapture method


  1. Use a trap to capture some animals

  2. Mark the captured animals

  3. Release the animals

  4. Set up the trap again in a couple of days

  5. Note the number of animals in the recapture and the number of those that are marked
• Assumptions made when using the mark-release-recapture method: there are no births or deaths, there is no migration, the marking method does not affect the individual's ability to survive, the marks don't come off
• Two methods of pest control

  • Biological control
  • Pesticides
• Biological control


  It is a method of controlling plant pests by deliberately introducing organisms that feed on the pests to decrease the number of them
• Trials are needed before the introduction of biological control to determine the effect on non-target species and assess the effectiveness of the chosen biological control method