. Pepper colors range from bright red, orange, and yellow shades, to dark green and brown shades. Coloration in bell peppers is controlled by alleles for two genes: Red (R) is incompletely dominant to yellow (r) and No chlorophyll (G), no green pigment, is dominant to chlorophyll (g), green pigment. A. You cross a red pepper with a green pepper and all the F1 progeny are orange. 1 pt What are the genotypes of the red and green parents? What is the genotype of the F1’s? B. What genotypes and phenotypes, in what proportions, do you expect in the F2 progeny of the orange F1 peppers? 2 extra credit points

All crosses and proportions, genotypes and phenotypes are attached.

Explanation:

a. Within living organisms, staining is a characteristic governed by a polygenic inheritance, which means that there is more than one gene involved in the staining process. as you already know, each gene has two alleles, if a trait is controlled by 2 genes, it means that we will have 4 alleles at the crosses.

From the description between dominance and recessivity between the alleles that control the colors of the pepper, shown in the question above, we can see that for the crossing between a red pepper and a green pepper, being able to generate a completely orange offspring, it would be necessary that the genotype of the parent peppers was: Red: RGRG, green: rgrg.

This would generate an orange-colored RrGg offspring, as you can see at the F1 crossing.

b. When individuals of F1 offspring are crossed, the combination of alleles and the determination of genotypes and phenotypes becomes much more complex, because instead of 4 alleles, we will have the combination of 16 alleles among themselves. Once again we will need to rely on the description of dominance and recessivity shown in the question above, so that from the crossing between the alleles of each gene, we can reach a conclusion, as you can see in the F2 crossing.