Chapter 2, Problem 41P

Humans vary in many ways from one another. Among many minor phenotypic differences are the following five independently assorting traits that (sort of) have a dominant and a recessive phenotype: (1) forearm hair (alleles F and f )—the presence of hair on the forearm is dominant to the absence of hair on the forearm; (2) earlobe form (alleles E and e)—unattached earlobes are dominant to attached earlobes; (3) widow's peak (alleles W and w)—a distinct “V” shape to the hairline at the top of the forehead is dominant to a straight hair-line; (4) hitchhiker's thumb (alleles H and h)—the abil-ity to bend the thumb back beyond vertical is dominant and the inability to do so is recessive; and (5) freckling (alleles D and d)—the appearance of freckles is domi-nant to the absence of freckles. In reality, the genetics of these traits are more complicated than single gene varia-tion, but assume for the purposes of this problem that the patterns in families match those of other single-gene variants.

If a couple with the genotypes Ff Ee Ww Hh Ddand Ff Ee Ww Hh Dd have children, what is the chance the children will inherit the following characteristics?

a. the same phenotype as the parents

b. four dominant traits and one recessive trait

c. all recessive traits

d. the genotype Ff EE Ww hh dd