Answer:
The I and B alleles exhibit incomplete dominance.
Step-by-step explanation:
When an animal or plant is said to be heterozygous, this means that its alleles are not dominant. For the heterozygous dogs to be medium-sized dogs, this shows that the I and B alleles as stated earlier did not exhibit complete dominance. What this means is that it borrowed some traits from large dogs and small traits from the small dogs and in terms of size, none of the dog types dominated.