2.1 bio- classification and biodiversity

• Groups organisms can be broadly classified into

  • Plants (flowering and non-flowering)
  • Animals (vertebrate and invertebrate)
  • Fungi
  • Protoctists (single celled organisms)
  • Bacteria
• Classification


  The organisation of organisms into groups
• Importance of classification


  • Makes it easier to identify organisms
  • Aids communication between scientists
• Scientific name


  • Given in two words
  • First name (genus) begins with a capital letter
  • Second name (species) begins with a lowercase letter
  • Words written in italics, or if handwritten underlined
• Types of adaptation


  • Morphological (structural)
  • Behavioural
• Adaptation


  Characteristics of an organism that increase its chance of survival, maintained by natural selection
• Resources organisms require from the environment

  • Light
  • Food
  • Oxygen
  • Carbon dioxide
  • Water
  • Minerals
• Resources are limited, creating competition between organisms
• Competition, as well as predation, disease and pollution, limits population sizes within a community
• Competition is the driving force of evolution by natural selection
• Components of biodiversity


  • Species diversity (variety of living organisms)
  • Genetic diversity (number of different genes)
  • Ecosystem diversity (range of ecosystems)
• Importance of biodiversity


  • Safeguards future food supplies
  • May contain chemicals for future medicines
  • Reduces damage to food chains
  • Protects valuable future resources
  • Creates stable ecosystems
  • Aesthetic reasons
  • Ecotourism benefits communities
• Ways to maintain biodiversity

  • Protection of endangered species
  • Conservation schemes to protect ecosystems
  • Reforestation
  • Sustainable farming
  • Minimising global greenhouse gas production
  • Legislation to protect habitats
  • Seed banks
• Passing legislation to protect habitats can be difficult because the needs of the human population sometimes conflict with the conservation of the environment
• It is important to balance the need for resources with the need to preserve the biodiversity of ecosystems
• Quadrats


  • Square frame divided into smaller square sections
  • Used to count members of each species present or estimate % coverage
• Using quadrats to sample biodiversity

  1. Position two 20m tape measures at right angles

  2. Use random number generator to select x and y coordinates

  3. Place quadrat at coordinate point

  4. Identify and record numbers or % coverage of each species
• Capture-recapture technique


  • Used to sample animal populations
  • Capture and mark individuals, then recapture and count marked individuals to estimate total population
• Accurate results from capture-recapture technique require adequate time between samples, no significant population movement, marking method that does not affect survival or recapture probability, and few births or deaths
• Biological control


  Introduction of a new organism into an ecosystem to control a pest or pathogen
• Alien species introduced for biological control may grow out of control, outcompete or prey on existing species, or carry new diseases
• Detailed research and trials must be carried out before introducing alien species