Selective breeding

• why Selective breed

  • dogs - to have a gentle nature
  • food crops - disease resistant
  • cows/farm animals - have more meat/milk
  • plants - to produce larger or unusual ones
• eg. Selective breeding cows:

  • select ideal/largest male/female
  • breed them
  • the sexual reproduction produces variation so still a mix of large cows and small
  • choose largest male/female offspring and breed them
  • continue for lots of generations until all offspring are large
• Disadvantages

  • breeding closely relates animals could cause inbreeding (can cause animals to get inherited defects)