For human blood type, the alleles for types A and B are codominant, but both are dominant over the type O allele. The Rh factor is
separate from the ABO blood group and is located on a separate chromosome. The Rh+ allele is dominant over the Rh- allele.
Indicate the possible phenotypes from the mating of a type O- woman with a type A+ man. Keep in mind that while there is only one
possible genotype for blood type O-, there are four possible genotypes for an A+ blood type. Consider all of them.
Hint: the genotype for the O- mother is IoIo Rh-Rh-(which may be expressed as O-O-); therefore, she produces IoRh-(or O-) gametes only.
To determine the possible phenotypes from the mating of a type O- woman (genotype IoIo Rh-Rh-) with a type A+ man (genotype IAIA Rh+), we need to consider the possible genotypes of the A+ blood type.
The possible genotypes for an A+ blood type are:
1. IAIA Rh+
2. IAi Rh+
3. IAIA Rh-
4. IAi Rh-
Now let's consider the possible combinations of genotypes and Rh factors for the offspring:
1. IAIA Rh+ (from father) x IoIo Rh- (from mother)
Offspring genotype: IAi Rh+ (A+)
2. IAi Rh+ (from father) x IoIo Rh- (from mother)
Offspring genotype: IAi Rh+ (A+)
3. IAIA Rh- (from father) x IoIo Rh- (from mother)
Offspring genotype: IAIA Rh- (A-)
4. IAi Rh- (from father) x IoIo Rh- (from mother)
Offspring genotype: IAi Rh- (A-)
Therefore, the possible phenotypes from the mating of a type O- woman with a type A+ man are A+ and A- blood types.