The gene (IGF1) that encodes a growth hormone has one allele (IGF1-A) that is found in small dogs but not in dogs that are very large. What does this suggest about body size of small dogs?

Question

A. Body size depends on how much growth hormone is produced during early fetal development.
B. Body size depends on whether or not the IGF1-A allele is present, if it is the dog grows very large, if it is not present the dog retains a small size.
C. It suggests that small dogs are small because the IGF1-A allele is expressed, perhaps inhibiting the growth of the dog and the release of growth hormone.
D. It suggests that small dogs have more growth hormone released during fetal development but none released after the birthing process.
E. Body size depends on nutrition, not on genetics.

Answer 1

C. It suggests that small dogs are small because the IGF1-A allele is expressed, perhaps inhibiting the growth of the dog and the release of growth hormone.