Inherited disorders

• What is the purpose of IVF embryo screening?

  To analyze genes before embryo implantation
• What can be detected through embryo gene analysis?

  Genetic disorders in the embryo
• What can parents choose if alleles are 'bad'?

  To have the embryos destroyed
• What are the pros of embryonic screening?

  • Saves money on treating disorders
  • Reduces overall suffering
  • Laws prevent extreme selection (e.g., sex selection)
• What are the cons of embryonic screening?

  • Suggests genetic disorders are 'undesirable'
  • Potential for selective breeding of desirable traits
  • Screening can be expensive
• What is cystic fibrosis?

  A genetic disorder of cell membranes
• What is produced excessively in cystic fibrosis?

  Too much mucus in air passages
• What causes cystic fibrosis?

  Caused by a recessive allele 'ff'
• What is the genotype for homozygous dominant cystic fibrosis?

  'FF'
• What is the genotype for homozygous recessive cystic fibrosis?

  'ff'
• What is the genotype for heterozygous cystic fibrosis?

  'Ff'
• What is polydactyl?

  A genetic disorder with extra fingers or toes
• What causes polydactyl?

  Caused by a dominant allele
• What is the genotype for homozygous dominant polydactyl?

  'PP'
• What is the genotype for heterozygous polydactyl?

  'Pp'
• What is the genotype for homozygous recessive polydactyl?

  'pp'
• How does the inheritance pattern of cystic fibrosis differ from polydactyl?

  Cystic fibrosis is recessive, polydactyl is dominant