When red-fruited and yellow-fruited tomatoes are crossed, the red-fruited one dominates in F1.

When red-fruited and yellow-fruited tomatoes are crossed, the red-fruited one dominates in F1. What will the offspring be in terms of genotype and phenotype if you cross a hybrid of the first generation with a constant yellow-fruited tomato?

Let’s denote the gene responsible for red fruits – A, and for yellow fruits – a

In the first generation, when crossing red-fruited and yellow-fruited tomatoes, we get the genotype of F1 – Aa.

If we cross tomatoes of this genotype with a constant yellow-fruited tomato, we get the following variants of genotypes:

AA Aa aa

Of these, AA and Aa will be red-fruited, and aa will have yellow fruits. Thus, the phenotypic ratio of red-fruited tomatoes in relation to yellow-fruited will be 2: 1