Apurebred plant that produces yellow seeds is crossed with a purebred plant that produces green seeds. the f1 plants have yellow seeds. what is the expected phenotypic ratio of seed color of the offspring of an f1 × f1 cross?

3 yellow : 1 green

Explanation:

Let yellow seed trait be represented by Y allele and green seed trait by y allele.

Purebred yellow seed plant = YY

Purebred green seed plant = yy

YY   x    yy  = Yy, Yy, Yy, Yy (all yellow)

This thus means that yellow seed trait is dominant over green seed trait.

F1  x   F1 = Yy  x   Yy, resulting in YY, Yy, Yy, yy offspring.

Since Y is dominant over y,

YY, Yy, Yy = Yellow

yy  = green

Hence, the expected phenotypic ratio of seed color of the offspring of F1 x F1 cross is 3 yellow : 1 green