The F phenotypic ratio of a dihybrid cross is?
| 1. | 1 : 1 : 1 : 1 | 2. | 1 : 1 |
| 3. | 9 : 3 : 3 : 1 | 4. | 1 : 4 : 6: 4 : 1 |
In Mendel's experiments with garden peas, round seed shape (RR) was dominant over wrinkled seeds (rr), and yellow cotyledon (YY) was dominant over green cotyledon (yy). What are the expected phenotypes in the F2 generation of the cross RRYY x rryy?
| 1. | Only round seeds with green cotyledons |
| 2. | Only wrinkled seeds with yellow cotyledons |
| 3. | Only wrinkled seeds with green cotyledons |
| 4. | Round seeds with yellow cotyledons and wrinkled seeds with yellow cotyledons |