The diagram below shows a simplified version of the biochemical pathway responsi
ID: 35302 • Letter: T
Question
The diagram below shows a simplified version of the biochemical pathway responsible for fruit color in peppers. Assume that Enzyme 1 is encoded by gene A (a is a null allele), Enzyme 2 is encoded by gene B (b is a null allele), and Enzyme 3, which breaks down the chlorophyll present in the fruit, is encoded by gene C (c is a null allele). In the absence of Enzyme 3, the fruit takes a brown color in the presence of red pigment, but remains green in the absence of red pigment. A pepper plant that produces red fruits was selfed, and the progeny obtained consisted of 176 plants that made red fruits, 78 that made colorless fruits, and 62 that made yellow fruits. If the original red fruit-producing plant was crossed to a tester of genotype a/a; b/b; c/c, what would be the expected phenotypic ratio in the offspring ?
The diagram below shows a simplified version of the biochemical pathway responsible for fruit color in peppers. Assume that Enzyme 1 is encoded by gene A (a is a null allele), Enzyme 2 is encoded by gene B (b is a null allele), and Enzyme 3, which breaks down the chlorophyll present in the fruit, is encoded by gene C (c is a null allele). In the absence of Enzyme 3, the fruit takes a brown color in the presence of red pigment, but remains green in the absence of red pigment. A pepper plant that produces red fruits was selfed, and the progeny obtained consisted of 176 plants that made red fruits, 78 that made colorless fruits, and 62 that made yellow fruits. If the original red fruit-producing plant was crossed to a tester of genotype a/a; b/b; c/c, what would be the expected phenotypic ratio in the offspring ? Enzyme 1 Enzyme 2 Colorless precursor rightarrow Yellow pigment rightarrow Red pigment Enzyme 3 Chlorophyll (green) rightarrow Absence of chlorophyllExplanation / Answer
the phenotypic ratio is 3:1