Family Trees

• What are family trees sometimes called?

  Family pedigrees
• What type of disorder is cystic fibrosis?

  Recessive inherited disorder
• How many cystic fibrosis alleles are needed to have the disease?

  Two cystic fibrosis alleles
• How are cystic fibrosis alleles represented?

  Lowercase f
• How is the healthy version of the cystic fibrosis allele represented?

  Uppercase F
• What genotype indicates a person has cystic fibrosis?

  Homozygous recessive genotype
• What genotype indicates a carrier of cystic fibrosis?

  Heterozygous genotype
• What does a half-shaded shape represent in a family pedigree?

  Carrier of the condition
• What do circles and squares represent in a family pedigree?

  Circles represent females, squares represent males
• What does a shaded shape indicate in a family pedigree?

  Person has the condition
• How can you determine the genotype of individuals in a pedigree?

  By analyzing the diagram and key
• What does each new row in a family tree represent?

  A new generation
• What does a horizontal line connecting two shapes indicate?

  They are a couple
• What is the genotype of Paul, who is a carrier?

  Capital F lowercase f
• What genotypes do Anna and Lucy have?

  Both are heterozygous carriers
• What is the genotype of Sam's wife who has cystic fibrosis?

  Lowercase f lowercase f
• If Lucy and Jack have a baby, what is the chance of the baby having cystic fibrosis?

  1 in 4 chance
• What genotypes do Lucy and Jack have?

  Both are heterozygous carriers
• What is the purpose of a Punnett square in genetics?

  To predict offspring genotypes
• What is the probability of the baby being a carrier?

  2 in 4 chance
• What is the probability of the baby being completely unaffected?

  1 in 4 chance
• What are the key components of a family pedigree?

  • Circles represent females
  • Squares represent males
  • Shaded shapes indicate affected individuals
  • Half-shaded shapes indicate carriers
  • Each row represents a new generation
• How do you determine the genotypes of individuals in a family tree?

  1. Analyze the symbols and shading
  2. Use the key provided
  3. Identify relationships and inheritance patterns
• How do you calculate the probability of a child having cystic fibrosis from two carriers?

  1. Identify parents' genotypes (both heterozygous)
  2. Create a Punnett square
  3. Analyze the results for probabilities