CB4

• 5 stages of Darwin's theory

  Genetic variation, Environmental change, Natural selection, Inheritance and evolution
• classification


  The organisation of living things into groups according to their similarities

  Can be based on: Physical traits, behaviour, diet and DNA
• The 5 kingdoms 


  Animals, Plants, Fungi, Protists, Prokaryotes
• Three domains of classification

  Archaea

  Bacteria

  Eukarya
• Artificial selection


  When humans choose certain organisms because they have useful characteristics
• How are sheep selectively bred to produce lots of wool?

  The farmer selects the naturally hairy/woolly sheep to breed together

  They then select the most hairy offspring and use them to breed

  The more they repeat this process, the more woolly sheep they will have
• What characteristic might be selectively bred for

  Disease resistance, Coping with environmental conditions, Yield, Flavour, Fast growth
• Genetic engineering 


  When a scientist takes genes from one organism and puts them into another
• Disadvantages of selective breeding

  -slow

  -involves a lot of genes

  -mixes genes at random
• Risks of selective breeding

  Only certain alleles are selected, others become rare or disappear. They could have been useful

  animal welfare is a concern