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Pedigree and Genetics Quiz

Use the pedigrees below to answer these questions. The shaded symbols represent individuals with a trait. An example of this trait includes Huntington's disease.
 

Pedigree 1 - polydactyl trait

  1. How many generations are shown ? _______
  2. How many male children did couple A-B have ? ______
  3. List the aunts that child J has : _______________
  4. What is the relationship between I and K ? __________
  5. What is the relationship between A-B and I, J and K ? __________
  6. Can an affected individual have a parent who does not have the trait ?
  7. Let us assign the letter 'P' for the dominant allele and 'p' for the recessive allele. How many 'P' alleles does an individual need to express the trait ?
  8. List the phenotypes for these genotypes: 'PP', 'Pp', 'pp'.
  9. Is this a dominant or recessive trait ?
  10. What must be the genotype for B ?
  11. If A's genotype is 'Pp' and B's is 'pp', use a Punnett square to show the genotypes of their offspring.
  12. What are the odds that any of A-B's children would be polydactyl ?
  13. Use a Punnett square to show that A's genotype must be 'Pp', not 'PP'.

 
 

Pedigree 2 - attached earlobes trait

Examples of this trait includes cystic-fibrosis, Tay-Sachs and sickle cell anemia.

  1. How many generations are shown ? _______
  2. How many male children did couple A-B have ? ______
  3. List the aunts that child J has : _______________
  4. What is the relationship between I and C ? __________
  5. What is the relationship between A-B and J, G and H ? __________
  6. Can an affected individual have a parent who does not have the trait ?
  7. Let us assign the letter 'F' for the dominant allele and 'f' for the recessive allele. How many 'f' alleles does an individual need to express the trait ?
  8. List the phenotypes for these genotypes: 'FF', 'Ff', 'ff'.
  9. Is this a dominant or recessive trait ?
  10. What must be the genotype for A ?
  11. If A's genotype is 'ff' and B's is 'FF', use a Punnett square to show the genotypes of their offspring.
  12. What are the odds that any of A-B's children would express attached earlobes ?
  13. Use a Punnett square to show that B's genotype must be 'FF', not 'Ff'.