The Punnett square shows that one parent carries the recessive gene for a cleft chin (c) while the other parent does not. What percentage of the parents' offspring is predicted to have a cleft chin?

The correct answer is 0%. If one parent carries the recessive gene for a cleft chin while the other parent does not, none of the offspring will express the recessive phenotype. This is because in order for a child to have a cleft chin, they would need to inherit the recessive gene from both parents. Therefore, although the offspring could be carriers of the gene, none are predicted to have a cleft chin. Choices A, B, and D are incorrect because the presence of the recessive gene in one parent and its absence in the other would not result in any offspring showing the cleft chin trait.