variation

• What is variation in populations?

  Differences in characteristics of individuals
• What can cause variation in populations?

  Differences in genes, environment, or both
• What is a mutation?

  A change in DNA sequence
• How does genetic variation arise in a population?

  Through continuous mutations
• What is the significance of a new phenotype arising from a mutation?

  It can lead to rapid species change
• What is the theory of evolution by natural selection based on?

  New phenotypes suited to environmental changes
• What is selective breeding?

  Humans breed plants and animals for traits
• How long have humans been using selective breeding?

  For thousands of years
• What are the steps in the process of selective breeding?

  1. Choose parents with desired traits
  2. Breed them together
  3. Select offspring with desired traits
  4. Continue over generations
• What characteristics can be targeted in selective breeding?

  Usefulness or appearance of traits
• What is a disadvantage of selective breeding?

  Can lead to inbreeding and defects
• How does selective breeding affect variation in a species?

  It reduces variation in the species
• What is genetic engineering?

  Changing an organism's genome by gene introduction
• What are genetically modified (GM) crops?

  Crops engineered for better traits
• What are the benefits of genetic engineering?

  Overcoming inherited diseases and higher yields
• What is a risk associated with genetic engineering?

  Spread of GM genes to wild species
• What ethical concerns are associated with genetic engineering?

  Manipulating genes of fetuses for traits
• What is a concern regarding the long-term effects of GM crops?

  Health effects of eating GM crops are unclear