Classification and biodiversity

• Major groups of living organisms

  • Plants
  • Animals
• Types of plants


  • Flowering (daisy, rose, dandelion)
  • Non-flowering (mosses, ferns)
• Types of 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, more recently DNA analysis used to more accurately group organisms to show how related they are
• Domains


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


  • Animals
  • Plants
  • Fungi
  • Single celled organisms
  • Bacteria
• Taxonomic levels (from largest to smallest)


  • Domain
  • Kingdom
  • Phylum
  • Class
  • Family
  • Genus
  • Species
• Genus


  The first part of an organism's scientific name, starts with a capital letter (e.g. Panthera)
• Species


  The second part of an organism's scientific name (e.g. tigris)
• Scientific names are used as they are universal, avoiding confusion from language barriers or common names
• Adaptations


  • Living things become adapted to their habitat, these may be morphological or behavioural
• Morphological adaptations


  • Fennec foxes have large ears to radiate heat, Arctic foxes have small furry ears to reduce heat loss
• Behavioural adaptations


  • Fennec fox is mostly nocturnal and burrows under sand to avoid heat
• Types of competition


  • Interspecific (between different species)
  • Intraspecific (between members of the same species)
• What organisms compete for

  • Animals: food, territory, mates
  • Plants: light, water, minerals
• Other factors affecting population size

  • Predation
  • Pollution
  • Disease
• Biodiversity


  Measure of the variety and numbers of different species in a particular area
• Biodiversity is important as it provides food, industrial materials, new medicines, and enhances human well-being
• Ways to conserve biodiversity and protect 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. Randomly throw quadrat

  2. Count different species and numbers in each quadrat

  3. Take mean number of each species

  4. Multiply up to estimate whole area
• Measuring animal biodiversity using capture-recapture

  1. Carefully collect organisms from 1 area

  2. Mark and return them

  3. Leave time for reintegration

  4. Recollect marked and unmarked samples

  5. Use equation to calculate estimated population size
• Biological control


  Use of one organism to control the population size of another species by eating it, often a predator controlling a pest
• Predator


  An animal that hunts and eats another for food
• Prey


  An animal that is eaten by a predator
• Pest


  An organism that eats a crop plant
• Native species


  An organism that lives in the country
• Alien species


  An organism introduced into a country in which it does not normally live
• Invasive species


  An alien organism that has had a negative effect on the native species