511 Solved problems brachytic locus ( b ) is on the orange chromosome. But where? For the purpose of the diagram, it doesn’t matter where we put it, but it does matter genetically because the position of the b locus affects the ratios in the prog-eny. If we assume that the b locus is near the tip of the piece that is translocated, we can redraw the pedigree: determines a normal gait. After crossing the true-breeding waltzers and normals, we observe that most of the F 1 is normal, but, unexpectedly, there is one waltzer female. We mate the F 1 waltzer with two different waltzer males and note that she pro-duces only waltzer progeny. When we mate her with normal males, she produces normal progeny and no waltzers. We mate three of her normal female prog-eny with two of their brothers, and these mice pro-duce sixty progeny, all normal. When, however, we mate one of these same three females with a third brother, we get six normals and two waltzers in a lit-ter of eight. By thinking about the parents of the F
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