Variation

• What is variation in a population?

  Differences in characteristics of individuals
• What are the three causes of variation?

  Genetic causes, environmental causes, both
• What are examples of genetic causes of variation?

  • Eye colour
  • Blood type
  • Natural hair colour
• What are examples of environmental causes of variation?

  • Language
  • Scars
  • Tattoos
• What are examples of variations caused by both genetics and environment?

  • Height
  • Weight
  • Hair colour and length
• What is genetic variation a product of?

  Mutations, sexual reproduction, and meiosis
• What is a mutation?

  A change in the DNA code
• How can mutations affect phenotype?

  They may have no effect or influence phenotype
• How does a mutation affect the protein coded by a gene?

  The protein it codes for may be different
• What is selective breeding also known as?

  Artificial selection
• What is the main purpose of selective breeding?

  To breed plants and animals for specific traits
• What is one reason for selective breeding in animals?

  To produce domestic dogs with gentle natures
• What is another reason for selective breeding in animals?

  To produce more meat or milk
• What is a reason for selective breeding in plants?

  To create large or unusual flowers
• What are the steps in the process of selective breeding?

  1. Select existing stock with desired traits
  2. Breed them together
  3. Select the best offspring and breed them
  4. Repeat over several generations
• What is a potential benefit of selective breeding in agriculture?

  It can improve crop yields
• What is a problem associated with selective breeding?

  It can lead to inbreeding
• What is a consequence of inbreeding in selective breeding?

  More prone to disease or inherited disorders
• What happens to the gene pool due to selective breeding?

  It reduces the number of different alleles
• What could happen if the environment changes after selective breeding?

  The species could become extinct
• Why might a species become extinct due to selective breeding?

  All individuals have the same genetic make up