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ThomasMagnus
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Homework Statement
Mendel's explanation for the monohybrid crosses predicts that the phenotypic 3:1 ratio in the F2 can be explained by an underlying genotypic ratio of 1:2:1 (eg. 1PP:2Pp:1pp). How could you test to see if the purple flowered F2 were really in the ratio of 1PP:2Pp?
Homework Equations
The Attempt at a Solution
Starting from the beginning, there would have to be 2 homozygous parents, one with the recessive trait (white flowers, p) and the other with the dominant trait (Purple flowers, P).
P: PP x pp
F1 : Pp --> Self breeding the F1 will always give an F2 with a 1PP:2Pp:1pp ratio (when set up in the punnet square). Both Pp's will have purple flowers, PP will also have purple flowers, and pp will have white flowers, ie a 3:1 ratio. So to test if the F2 was really in a 1PP:2Pp ratio you could do a test cross. If you crossed it with a homozygous recessive plant, you would get a 1Pp:1pp ratio out. Would this be enough to prove it? Is it only possible to output a 1Pp:1pp ratio if the purple one was in a 1PP:2Pp ratio? how does it prove it?Does my reasoning seem correct, or am I just going around in circles with my explanation?