Natural selection and genetic modification

• Class order

  Domain

  Kingdom

  Phylum

  Class

  Order

  Family

  Genus

  Species
• Darwin’s theory of evolution

  • Variation in a population
  • Individuals with better suited characteristics survive, less suited die
  • More suited survive and reproduce, and adaptations pass on to next generation
  • Repeats
  • More favourable characteristics become more common, less favourable characteristics become less common
• Evidence for human evolution

  • Longer femur bone
  • Increase skull volume
  • More complex stone tools
• Reasons for natural selection to take long time for acceptance

  • Religion
  • Lack of evidence
  • DNA not discovered
• Antibiotic Resistance

  • Bacteria infects a person
  • Some bacteria develop random mutation with resistance to antibiotic
  • Antibiotic kills of bacteria which are less resistant, more resistant survive and reproduce
  • Resistant allele passed on
  • Resistant bacteria more common in population
• Reasons for resistance

  • People not completing full antibiotic course
  • Doctors prescribe antibiotics when not necessary
  • People take antibiotic when they have viral infection
• Genetic engineering

  • Cut out DNA with restriction enzymes
  • Remove plasmids and make cuts with same restriction enzymes
  • Join plasmid with complementary sticky ends Using ligase
  • Insert plasmid back into bacteria
• Benefits of GM

  • increased yield
  • Increased quality
  • Resistant to disease
• Tissue culture

  • Pick parent plant, remove cuttings of tissue
  • Place tissue in growth medium with nutrients and growth hormone under ASEPTIC and sterile conditions
  • Remove and grow in plotting compass to carry on growth
• Selective breeding

  • pick 2 parents with desirable characteristics
  • Breed together
  • Pick best offspring with desirable characteristics and breed again
  • Repeat over multiple generations
• Problems - selective breeding

  • Reduction of gene pool
  • No variation - easily wiped out if disease
  • Inbreeding - more likely hood of genetic defects
• World GM

  • Increases food production
  • Helps world hunger
  • Combat deficiencies