Final answer:
When parents who are heterozygous for unattached earlobes and cleft chin are crossed, their offspring have a 50% chance of having unattached earlobes and a 50% chance of having attached earlobes. Similarly, their offspring have a 50% chance of having a cleft chin and a 50% chance of having a smooth chin.
Step-by-step explanation:
In this case, the parents are heterozygous for both unattached earlobes and cleft chin. Unattached earlobes are dominant to attached earlobes, so if one parent has unattached earlobes (genotype Ff) and the other parent has attached earlobes (genotype ff), then the offspring will have a 50% chance of having unattached earlobes (genotype Ff) and a 50% chance of having attached earlobes (genotype ff).
Similarly, cleft chin is dominant to no cleft. If one parent has a cleft chin (genotype BB) and the other parent has a smooth chin (genotype bb), then the offspring will have a 50% chance of having a cleft chin (genotype Bb) and a 50% chance of having a smooth chin (genotype bb).