Question

In the summer squash, fruits may be white, yellow, or green. In one case, the cross of yellow X white produced an F1 of all white-fruited plants that, when selfed, gave an F2 segregating 12 white: 3 yellow: 1 green. (a) suggest gnotypes for the white, yellow, and green phenotypes. (b) give genotypes of the P, F1, and F2 of this cross.

Answer 1

P: Yg x WW yellow x white
F1: YW,YW, gW, gW all white
F2:
first two YY,YW,WW,YW one Yel, 3W
first, third Yg,YW,Wg,WW one Yel, 3W
first, fourth Yg,YW,Wg,WW one Yel, 3W
second third Yg,YW,Wg,WW one Yel, 3 W
third, fourth gg,gW, Wg, WW one g, 3W
now if W dominates to y,g, and Y dominates to g, then I count 15/20 W, 1/20 g, and 3/20 yellow
Now in the F2 above, there were 12/16 W,3/16 Yellow, and 1/16 green Those frequencies look very close to what I laid out.
White 12
Yellow 4
green

Answer 2

can you explain step by step how you got these answers? I have tried many ways and I'm still not understanding it.