Incomplete Dominance

  1. In snapdragons, flower color is an incompletely dominant trait. If a red flower is crossed with a pink flower, what is the percent chance that their offspring will be pink?
  2. A rabbit with black fur color is crossed with a rabbit with white fur color. Show the Punnett square and explain the potential phenotypes of the offspring
  3. Out of 10 flowers from one set of parents, all the flowers are pink. What is most likely the genotypes of the parents? Show a Punnett square to support your answer.

Co-dominance

  1. Blood types in humans are an example of co-dominance. If a father with blood type A mates with a mother with blood type B what are all the possible genotypes of their children? Show Punnett squares (more than 1) to support your answer.
  2. Johnny has blood type O. His mother has blood type A and his father has blood type B. Is it possible that those are Johnny’s biological parents? Use a Punnett square to support your answer.
  3. In chickens, feather color is a co-dominant trait. A black-feathered chicken is mated with a white-feathered chicken. Show a Punnett square and give the percent chance that their chicken offspring will have white feathers.

Simple dominant/recessive

  1. In frogs, spots is dominant to no spots. A homozygous spotted frog mates with a frog with no spots. Show a Punnett square and give the genotypic and phenotype ratios.
  2. In fish, yellow scales are recessive to red scales. A heterozygous fish mates with a yellow-scaled fish. What is the chance that their child will have yellow scales? Show a Punnett square to support your answer.
  3. Two plants that are heterozygous tall are mated. Give the phenotypic and genotypic ratios for the cross.

X-linked traits

  1. A mother that is a carrier for hemophilia marries a man with hemophilia. What is the chance that their daughters will have hemophilia?
  2. A mother that is a carrier for colorblindness marries a normal man. What is the chance that their children will be colorblind?
  3. A normal mother marries a man with the gene for baldness. What is the chance that their sons will be bald?

Multiple Alleles

  1. Susan has blood type AB. Her mother is homozygous for type A. What are the possible genotypes for the father assuming he is the biological father?
  2. Bobby has blood type A. His parents both have blood type AB. What does Bobby’s genotype have to be? Show a Punnett square to support your answer.
  3. Mary has blood type B and her husband has blood type O. If all 7 of their children have blood type B, what is most likely Mary’s genotype?

Type of Inheritance / Problem 1 / Problem 2 / Problem 3
Incomplete Dominance
Co-dominance
Simple dominant/recessive
X-linked traits
Multiple alleles