Classification and biodiversity

• Major groups of living organisms

  • Plants
  • Animals
• Plants


  • Flowering-like daisy, rose, dandelion
  • Non-flowering-like mosses and ferns
• Animals


  • Vertebrates- have a backbone like birds, snakes, humans
  • Invertebrates do not have a backbone like insects, spiders
• Classifying and naming organisms

  Traditionally based on morphological features but more recently DNA analysis has been used to more accurately group organisms to show how related they are
• Domains


  • Eukarya (which contains 4 of the 5 kingdoms)
  • Bacteria
  • Archaea
• Kingdoms


  • animals
  • plants
  • fungi
  • single-celled organisms
  • bacteria
• Taxonomic groups


  • Groups get smaller and organisms more similar as they have more morphological features (body structures) in common
• Scientific name


  The first part starts with a capital letter (genus) and the second part is the species
• Competition


  • Animals compete for food, territory and mates
  • Plants compete for light, water and minerals
• Types of competition


  • Interspecific competition - competition between different species
  • Intraspecific competition - competition between members of the same species
• Other than competition, the size of a population is changed by predation, pollution or disease
• Biodiversity


  A measure of the variety of different species and the numbers of each of those species in a particular area
• Importance of biodiversity


  • Provides food and potential foods
  • Provides industrial materials
  • Provides new medicines
  • Enhances human well-being
• Ways to conserve biodiversity and endangered species

  • Convention on International Trade in Endangered Species
  • Sites of Special Scientific Interest
  • Captive breeding programmes
  • National parks
  • Seed/sperm banks
  • Local biodiversity action plans
• Measuring plant biodiversity using quadrats

  1. Lay out two tape measures at right angles

  2. Use a pair of dice or a random number generator to generate co-ordinates

  3. Place the quadrat at those coordinates

  4. Count the different species and the number of each in each quadrat

  5. Take a mean number of each species of plant from all the quadrats collected

  6. Multiply up to estimate how many are in the whole area
• Measuring the distribution of plants can be carried out using quadrats set in a row 1m apart. This will give you an idea of how plant life changes along a particular route, e.g. along a seashore. This is called a transect.
• Measuring animal biodiversity using capture/recapture

  1. Carefully collect organisms found in 1 area without trampling the habitat or leaving litter

  2. Mark the organisms and return them to the same area they were collected from

  3. Leave time for organisms to reintegrate into their community

  4. Return and again collect as many organisms as found. Collect unmarked samples as well as as those that were already marked

  5. Use an equation to calculate the estimated population size
• Assumptions made when using capture/recapture data include no death, immigration or emigration, and that the marking technique does not affect chances of survival
• Biological control


  The use of one organism to control the population size of another species by eating it
• Organisms involved in biological control

  • Predator
  • Prey
  • Pest
  • Native species
  • Alien species
  • Invasive species
• A lot of research is needed to make sure that any alien species introduced into a habitat does not become invasive and affect the populations of the native species. The research is also needed to prevent any species introduced having a negative effect on non-targeted species.