Sagot :
Answer:
In a cross of AaBb x AaBb, what fraction of the offspring can be expected to express one of the two dominant alleles, but not both? Genotypes of all offspring: AABB, 2AABb, 2AaBB, 4AaBb, AAbb, aaBB, 2Aabb, 2aaBb, aabb. Fraction of the offspring with one of the two dominant alleles by gene А: 2AaBB, 4AaBb, 2Aabb