Part 3/7:
Humans inherit one allele from each parent, resulting in two alleles that dictate their blood type. The relationship between these alleles is crucial:
If both alleles are A, the resulting blood type is A.
If both alleles are B, the blood type is B.
If one inherits an A and a B allele, the blood type combines as AB due to codominance.
The presence of the O allele is recessive; thus, it does not manifest unless paired with another O, leading to type O blood.
Understanding how blood types are inherited aids in predicting the possible blood types of children based on the blood types of their parents.