|
P1: AAbb X aaBB white white | |||
| ↓ | |||
| F1: All AaBb (purple) | |||
| ↓ | |||
| F2 ratio | Genotype | Phenotype | Final Phenotypic ratio |
|---|---|---|---|
| 9/16 | A- B- | purple | 9/16 purple |
| 3/16 | A- bb | white |
7/16 white |
| 3/16 | aa B- | white | |
| 1/16 | aa bb | white | |
A cross between two strains of white-flowered sweet peas, the F1 plants are all purple,
and the F2 occurred in a ratio of 9/16 purple to 7/16 white.
The presence of at least one dominant allele of each of two gene pairs is required for
purple flowers.
Sometimes gene interaction can yield novel phenotypes in the F2 generation.