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Punnett squares

a. In guinea pigs, black coat color (B) is dominant over white coat color (b). When a true breeding black guinea pig is crossed to a true breeding white guinea pig, what is the probability that their progeny will be black? Explain.

b. If two heterozygous black guinea pigs are crossed, what fraction of their progeny will be black? Explain.

c. Lack of pigmentation (albinism) in humans is the result of a recessive allele (a), and normal pigmentation is the result of its dominant allele (A). Two normal parents have an albino child. Determine the probability that the next child is albino. Explain.

d. The genotypes of two individuals in a tetrahybrid cross are AABbCCDd and AabbccDD. What fraction of their offspring would be heterozygous for all four traits? (Assume independent assortment for all four traits, and show your calculations.)

e. A man of blood group B is being sued by a woman of blood group A for paternity. The woman's child is blood group O. Can this man be the father of this child? Explain.

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Punnett squares are the easiest way to look at genetics for ...

Solution Summary

This solutions provides a spreadsheet of punnett squares that looks at the odds of various genetic combinations. Primarily simple, 1-gene examples with 1 tetrahybrid.