Genetic Diagrams

• What is cystic fibrosis?

  An inherited genetic disorder affecting cell membranes
• Which type of allele causes cystic fibrosis?

  Recessive
• What does it mean to be a 'carrier' of cystic fibrosis?

  Has an allele for the disorder but no symptoms
• Why can't a healthy adult without the faulty gene have a child with cystic fibrosis?

  They pass on a healthy allele only
• What is polydactyly?

  An inherited disorder causing extra fingers and toes
• Why might Eve and Phil not be aware that they might have a baby with CF?

  They might not know they are both carriers
• How can you tell from the family tree that CF is caused by a recessive allele?

  Many family members carry the gene but lack CF
• What is the chance that the new baby will have CF?

  25%
• What is the chance that the baby will be a carrier for CF?

  50%
• What is the chance that the new baby will not have the faulty gene?

  25%
• What is done during embryonic screening?

  • Screening embryos for genetic disorders
  • Selecting healthy embryos for implantation
• What are the advantages and disadvantages of embryonic screening?

  Advantages:

  • Healthy baby
  • Saves NHS treatment costs

  
  

  Disadvantages:

  • Ethical concerns
  • Expensive
• Why might it be unfair to stop someone being born with Huntington's disease?

  They could have a good quality of life