Natural Selection + Genetic Modification

Natural Selection + Genetic Modification

1. genetic engineering

   • involves the use of enzymes + vectors (carriers)
   • involves modifying an organisms geneome (its DNA) to introduce desirable characteristics
   • enzymes can be used to cut up or join DNA. vectors can be used to insert DNA into other organisms

2. selective breeding

   • when features that are useful to humans are bred into plants and animals
   • also called artificial selection
   • disadvantages:
     • reduced variation (reduction in different alleles
     • health problems in animals
     • a change in the environment could wipe out the species
   • not just used in agriculture but also in medical research

3. tissue culture

   • parent plant -> tissue removed from tip of the plant -> tissue placed on a medium containing growth hormones
   • tissue culture in medicine
     • used to study viruses + medicine effects
     • dont need to test on humans
     • to avoid rejection in human replacement tissue

4. evolution

   • pendadactyl limb:
     • 5 phlanges
     • a humerous
     • a radius
     • an ulna
   • ARDI -> LUCY -> HOMO HABILUS -> HOMO ERECTUS -> HOMO SAPIENS (US!)
   • organisms COMPETE for food, water, mates etc
     • GENETIC VARIATION or MUTATION within a species means that some individuals are BETTER ADAPTED TO THEIR ENVIRONMENT.
       • the BETTER ADAPTED INDIVIDUALS survive long enough to REPRODUCE + PASS ON THEIR GENES (SURVIVAL OF THE FITTEST)
         • over a LONG PERIOD OF TIME, the ADVANTAGEOUS GENES will INCREASE IN POPULATION