When mendel crossed yellow-seeded and green-seeded pea plants, all the offspring were yellow-seeded. when he took these f1 yellow-seeded plants and crossed them to green-seeded plants, what genotypic ratio was expected?

The 50 % with a ratio of 1:2

Explanation:

In the first generation (F1) the yellow seeded peas have the dominant gene (SS) and the green the recessive gene (ss) that is the reason why all the offspring were yellow (Ss) because the dominant gene is present but they also have the recessive gene.

so in the second generation (F2) were crossed with a green pea (ss), the offspring will mix the dominant with the recessive genes,

                     S                s

s                     Ss               ss

s                     Ss               ss

with these results, the genetic of the half offspring will be (Ss, that mean, they are going to be yellow) and the other half will be ss (they are going to be green).