Flower color in snapdragons results from the amount of the pigment anthocyanin in the petals. Red flowers are produced by plants that have full anthocyanin production, and ivory-colored flowers are produced by plants that lack the ability to produce anthocyanin. The allele An1 has full activity in anthocyanin production, and the allele An2 is a null allele. Dr. Ara B. Dopsis, a famous genetic researcher, crosses pure-breeding red snapdragons to pure-breeding ivory snapdragons and produces F1 progeny plants that have pink flowers. He proposes that this outcome is the result of incomplete dominance, and he crosses the F1 to test his hypothesis. What genotypes does Dr. Dopsis predict will be found in the F2

The genotypes found in the F2 offspring will be An1An1, An1An2 and An2An2.

Explanation:

In the example given in the question, the color of the petals of snapdragon flowers are given with the An1 allele having full activity and the An2 allele being the null allele. For the F1 offspring, two snapdragon flowers are crossed, one with red petals which is An1An1 and one with ivory petals which is An2An2. All the genotypes for the F1 offspring will result in An1An2.

Then using this F1 offspring, the F2 offspring is found and the genotype of the F2 offspring will be An1An1 / An1An2 / An1An2 / An2An2.

So the genotypes found in the F2 offspring will be An1An1, An1An2 and An2An2. One red petal snapdragon, 1 ivory snapdragon and 2 pink snapdragons.

I hope this answer helps.