I am seeing both bad theology and bad science. Here is the deal on blood types.
Each chromosome is a pair, one side from each parent. Thus there are two genes that determine blood group and two genes that determine positive/negative (and every other genetic characteristic).
This is often expressed a phenotype and genotype. The phenotype is the effective blood type and is designated by a single letter. The genotype represents what genes you really have and is represented by two letters, one from each parent. One gene is always dominant and one is always recesive. In some cases, there can be mixture of dominants resulting in co-dominants.
So here are the blood types.
A is dominant.
B is dominant
O is recessive
Positive (+) is dominant
Negative (-) is recessive.
Potential genotypes: AA and AO, ++ or ±
Potential genotypes: AA and AO, – only
Potential genotypes: BB and BO, ++ or ±
Potential genotypes: BB and BO, – only
Potential genotypes: AB only, ++ or ±
Potential genotypes: AB only, – only
Potential genotypes: OO only, , ++ or ±
Potential genotypes: OO only, , – only
One can deduce the geno types of the parent from the phenotype of the children. And even what the genotype of the child may be as well.
Example: Father is A+, Mother is B-. Child has O+ blood.
Father’s genotype AO, ++ or ±.
Mother’s genotype BO, –
Genotype of mother’s egg O-
Genotype of father’s sperm O+
Therefore the son must have a genotype of OO, ±
Despite what s4angel has said, children always, 100% of the time with absolutely zero exceptions since the beginning of the universe get their blood types from their parents.
By the way, I happen to know the above example is true because this is my family and we have all been tested.
As for the theology, 1/2 of Jesus’ DNA cam from Mary. The other half came via (net necessarily from) the Holy Spirit and is of miraculous origin.