classification

• phylogeny: study of evolutionary history of groups of organisms
• taxa: eight levels of groups to classify organisms
• hierarchy: how groups are organised
• species: group of organisms share physical characteristics and can interbreed to produce fertile offspring
• Classification:

  • Domain
  • kingdom
  • phylum
  • class
  • order
  • family
  • genus
  • species
• courtship: attract a mate of right species
• How is courtship behaviour used to classify organisms

  specific for each organism

  the more closely related an organism is the similar the behaviour
• Methods of classification:

  • genome sequence
  • comparing amino acid sequence
  • immunological comparisons
  • courtship
• genome sequencing:

  • DNA base sequence used for comparison
  • if similar = closely related
• comparing amino acid sequence:

  • sequence of amino acids coded by DNA base sequence
  • related organisms have similar amino acid sequence
• immunological comparisons:

  • similar proteins will also bind to same ABs
  • E.g- AB binded to human protein will bind to protein from chimpanzee as similar to human
  • more binding = closely related
• Courtship:

  • specific for each species
  • prevents interbreeding (hybrid)
• Genetic diversity: estimated by looking at frequency of measurable or observable characteristics in population
• genetic diversity measured using gene tech:

  • mRNA sequences
  • genome/DNA sequence
  • Amino acid sequence
• variation: differences that exist between individuals which can be caused by genetic and environmental factors
• Biodiversity: variety of organisms in an area
• community: all the populations of different species in a habitat
• species richness: measure of number of different species in a community
• the higher the index diversity, the higher the biodiversity
• Impact of agriculture on biodiversity:

  • woodland clearance
  • hedgerow removal
  • pesticides
  • herbicides
  • monoculture
• woodland clearance/ hedgerow:

  • increases area for plant growth
  • reduces number of species
  • loss of habitats
  • animals compete for resources
• pesticides:

  • kills pests
  • loss of resource for animals feeding
  • predator numbers decrease = compete for resources
• herbicides:

  • reduce plant diversity
  • reduce number of organisms that feed
  • compete for resources
• monoculture:

  • fields only containing one type of plant
  • support fewer organisms
  • reduces biodiversity