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PEDIGREES AND PUNNETT SQUARES
For each problem choose the appropriate punnett square and draw a pedigree to
show your results.
1. Martians generally have blue faces, which is caused by a dominant gene. The recessive
condition results in an orange face. A blue faced martian (heterozygous) is married to an
orange faced martian. They have 8 children. How many children will have blue faces?
2. Martians can have red (dominant), blue, or purple hair. Purple hair results from the
heterozygous condition. Martin has purple hair and is married to Marce who brags that
she has the bluest hair in the valley. How many children will be able to brag about their
blue hair also?
3. One of Marce’s children is born with shocking red hair. Is Martin the father of this child
(show the square to prove your answer)? But wait, Marce swears she has been faithful and
claims that the hospital goofed and got her baby mixed with another. Is this a plausible
explanation. Show the square to prove your answer
4. Martians can have blue and yellow skin. Also, when a blue martian marries a yellow
skin martian, their children have blue and yellow spots. Two spotted martians get
married and have 5 children. What skin color will the children have?
5. A man, who’s mother was colorblind, marries a woman who’s father was colorblind.
What is the chance they would have a son who is colorblind? What is the chance they
would have a daughter who is colorblind? Colorblindness is a sex-linked recessive
condition.
6. A man with blood type A (heterozygous) marries a woman with blood type O. Find the
blood type for their 3 children.