Tomato flesh is typically red due to the production of

Last updated: 7/23/2022

Tomato flesh is typically red due to the production of lycopene, which is a carotenoid pigment. Some tomatoes may have tangerine-colored flesh or yellow-colored flesh. In the 1950's, researchers reported that this variation in tomato flesh color could be explained by an epistatic interaction involving genes T and R. Previous work had shown that red flesh is the wild-type phenotype, and that yellow flesh is caused by a recessive mutation at the R locus only. The researchers were not sure, however, how tangerine flesh was inherited. They established a cross between two double heterozygous red-fleshed tomatoes and observed the following offspring: 27 red- fleshed plants, 12 tangerine-fleshed plants, and 9 yellow-fleshed plants. Use this information to answer the following questions. (a) In general, what must the genotypes be for red-fleshed tomatoes, tangerine- fleshed tomatoes, and yellow-fleshed tomatoes, respectively? (b) You cross a heterozygous red-fleshed plant with a true-breeding yellow-fleshed plant. What are the genotypes of these two plants? What are the expected offspring phenotypes, and in what proportions? Use a punnett square or product law / forked line method to support your answer.