1.7 biodiversity and classification

• Classification


  The process of naming and organising organisms into groups based on their characteristics

  
• Five kingdoms of organisms


  • Animals
  • Plants
  • Fungi
  • Prokaryotes
  • Protoctists
• Taxonomic levels


  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species

  
• Binomial system


  The system of naming species, where the first part is the genus and the second part is the species
• Molecular phylogeny


  The analysis of molecular differences in different organisms to determine the extent of their evolutionary relatedness
• Three domains of life

  • Bacteria
  • Archaea
  • Eukaryota
• How the scientific community evaluates data

  1. Findings published in scientific journals

  2. Presented at scientific conferences

  3. Peer review

  4. Collecting evidence to support or reject suggestions
• Biodiversity


  The variety of living organisms
• Biodiversity


  Threatened by human activity such as deforestation
• Species richness


  The number of different species in a community
• Genetic diversity


  The measure of genetic variation found in a particular species, determined by the number of alleles in a gene pool and the heterozygosity index
• Index of diversity (D)

  A measure of biodiversity calculated using the formula: D = Σ(n/N)^2, where N is the total number of organisms and n is the total number of organisms of each species

  
• DNA profiling


  A forensic technique used to identify individuals by characteristics of their DNA and determine genetic relationships between organisms
• Polymerase chain reaction (PCR)

  1. Reaction mixture set up with DNA sample, primers, nucleotides and DNA polymerase

  2. Heated to 95°C to separate DNA strands

  3. Cooled to 50-65°C for primers to bind

  4. Heated to 70°C for DNA polymerase to create copies

  5. Cycle repeated 30 times to amplify DNA

  
• Gel electrophoresis


  Used to separate DNA fragments according to their size using an electric current