Question

In summer squash, white fruit color (W) is dominant over yellow fruit color (w) and disk-shaped fruit (D) is dominant over sphere-shaped fruit (d). If a squash plant pure breeding for white and pure breeding for disk-shaped fruit is crossed with a plant pure breeding for yellow, sphere-shaped fruit, what will the phenotypic and genotypic ratios be for:
the F1 generation?
the F2 generation?

Answer 1

P:    WWDD x wwdd
Formed gametes are WD and wd
F1 generation: WwDd all phenotypes are white and disc-shaped (dominant traits are expresed)
F2 generation: 9  :  3  :  3   :   1 are ratios of phenotypes (white and disc-shaped : white sphere-shaped : yellow disc-shaped : yellow sphere shaped).