A dragon's blue fire color is recessive and the orange fire color is dominant. You breed two breathing dragons with alleles that are heterozygous meaning the alleles are not identical, one is
dominant and one is recessive. What are the possible colors of the parents' offspring? How do you
know?

See the answer below

Explanation:

Let the color of fire by the dragon be represented by B for the dominant allele (orange fire color) and b for the recessive allele (blue fire color).

Two dragons that are heterozygous were bred:

                 Bb   x   Bb

           BB   Bb   Bb   bb

Since orange fire color (B) is dominant over blue fire color (b):

BB and Bb = orange fire color

bb = blue fire color

It means that 3/4 of the offspring from the parent will produce orange fire color while 1/4 will produce blue fire color.