Final answer:
The inheritance pattern when a yellow frog and a blue frog are crossed to produce green offspring is best described as Incomplete Dominance, where neither trait is completely dominant and the offspring show a mix of both parental traits.
Step-by-step explanation:
When a yellow frog and a blue frog are crossed, resulting in green offspring, the pattern of inheritance that best describes this situation is Incomplete Dominance.
Incomplete dominance occurs when the heterozygote expresses a phenotype that is intermediate between the phenotypes of both homozygotes, much like crossing black and white mice to produce gray offspring, or red and white snapdragons to produce pink offspring. This means that neither the yellow nor the blue trait is completely dominant over the other, leading to a mix or intermediate color in the green frog offspring.