In a family both parents have freckles and widow's peak.Both of these traits are dominant: F=freckles,W=widow's peak.What is the correct phenotypic ratio of the next generation if the parents were heterozygous? The order of the genotypes is: Freckled with widow's peak: Freckled,straight hairline: no freckles with widow's peak: no freckles,straight hairline.

Question

Quizplus · Accepted Answer

Since both freckles and widow's peak are dominant traits, the genotype of the heterozygous parents is FfWw. 
To predict the phenotypic ratio of their offspring, we need to use a Punnett square.

|   | F   | f   |
|---|---|---|
| W | FW | fW  |
| w | Fw | fw  |

Using this Punnett square, we can see that the possible genotypes of the offspring are: FW, Fw, fW, and fw. 
The corresponding phenotypes are: Freckled with widow's peak, Freckled with straight hairline, No freckles with widow's peak, and No freckles with straight hairline. 
The ratio of these possible phenotypes is 9:3:3:1, which is represented by answer choice B.

In a Family Both Parents Have Freckles and Widow's Peak