I stumbled upon a genetics question in a practice PCAT. It reads:
The following phenotypes are seen as a result of a genetic cross: purple flowers smooth seeds, purple flowers wrinkled seeds, white flowers smooth seeds, and white flowers wrinkled seeds. What are the parental genotypes?
a) PPSS x ppss
b) PpSs x PpSs
c) ppss x ppss
d) PpSs x ppss
The answer they give is: "B. the only way to get all four phenotypes (dominant and recessive) is to have both parents heterozygous for both dominant & recessive traits."
But wouldn't D also work?
The following phenotypes are seen as a result of a genetic cross: purple flowers smooth seeds, purple flowers wrinkled seeds, white flowers smooth seeds, and white flowers wrinkled seeds. What are the parental genotypes?
a) PPSS x ppss
b) PpSs x PpSs
c) ppss x ppss
d) PpSs x ppss
The answer they give is: "B. the only way to get all four phenotypes (dominant and recessive) is to have both parents heterozygous for both dominant & recessive traits."
But wouldn't D also work?