Answer Happy

In the flower petals of a particular plant species, the synthesis of red pigment requires two steps in a biochemical pathway as follows: Start with Yellow pigment --> gene A --> Orange Pigment --> gene B --> Red pigment The production of the enzyme required to turn the yellow pigment into the orange is encoded by the dominant A allele. The production of the enzyme required to turn orange pigment into red is encoded by the dominant B allele. [Select] A pure-breeding orange flower plant is crossed to a pure-breeding yellow flowered plant to produce F1 progeny that consists entirely of red flowered plants. What is the genotype of the yellow parent? What is the only possible genotype that produces a pure-bred [Select] orange flower? [Select] If the red F1 progeny are self-crossed, what is the ratio of phenotypes observed in the F2 generation? (Hint: for the first question, you may think there are multiple possible genotypes for the yellow parent. However, only one possible yellow-producing genotype would get you all red offspring. You may want to answer the second question first to help with this.)