Final answer:
The puppies will have wavy hair as a result of incomplete dominance.
Step-by-step explanation:
The puppies from the mating between a heterozygous curly-haired dog and a homozygous straight-haired dog will have different types of hair. This is an example of incomplete dominance, where the offspring express a phenotype that is intermediate between the two parents. In this case, the puppies will have wavy hair as a result of inheriting one allele for curly hair and one allele for straight hair.