Selective breeding

• What is selective breeding?

  Humans choose which plants or animals breed
• Why do organisms undergo selective breeding?

  To develop useful or attractive features
• What is the basic process of selective breeding?

  1. Select organisms with desired features
  2. Breed them together
  3. Select the best offspring and breed them
  4. Repeat over several generations
• What is the result of selective breeding over generations?

  All offspring will have the desired feature
• How might a farmer selectively breed cattle for more meat?

  Select the largest cows and bulls to breed
• What is a major disadvantage of selective breeding?

  It reduces the number of different alleles
• Why does selective breeding lead to health problems in organisms?

  Because closely related organisms are bred
• What happens if a new disease appears in selectively bred organisms?

  They are less likely to have resistance alleles
• What is the risk if one individual in a selectively bred population gets a disease?

  The rest are likely to be affected too
• What is the significance of genetic variation in selective breeding?

  It allows for better characteristics in offspring
• What is one use of selective breeding in agriculture?

  Producing crops with disease resistance
• What is the outcome of selective breeding for floppy ears in rabbits?

  Rabbits with floppy ears are produced
• How many marks is Q1 worth in the exam?

  4 marks
• How many marks is Q2 worth in the exam?

  1 mark
• What are the potential consequences of reduced genetic diversity in selective breeding?

  • Increased health problems
  • Vulnerability to new diseases
  • Higher risk of population decline