In guinea pigs, dark hair (D) is dominant over light hair (d) and curly hair (C) is dominant over smooth hair (c). Complete a dihybrid cross for parents with the genotypes: DdCc × DdCc and answer the following in complete sentences.
Describe how you would set up a Punnett square for this cross.
List the likelihood of each possible offspring genotype.
List the likelihood of each possible offspring phenotype.

Question

In guinea pigs, dark hair (D) is dominant over light hair (d) and curly hair (C) is dominant over smooth hair (c). Complete a dihybrid cross for parents with the genotypes: DdCc × DdCc and answer the following in complete sentences.
Describe how you would set up a Punnett square for this cross.
List the likelihood of each possible offspring genotype.
List the likelihood of each possible offspring phenotype.

blues · Answer

The key concept is that each of the parents two chromosomes with either of the two alleles can sort into different gametes. So the possible combinations for the gametes from the first parent are DC, Dc, dC and dc. The possible combinations for the second parent are the same (because the parents' genotypes are the same). These are what you put on the axes of your Punnett square.

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