Can A positive and B positive make O positive?

Answer 1

yes

Answer 2

Yes. Humans are diploid so every person inherits two versions of all genes that are not on the sex chromosomes (There are certain exceptions to this in conditions such as Downs syndrome). The gene determining the ABO blood group of the is not on a sex chromosome so every person inherits two copies of the gene. This gene has 3 versions known as alleles. The genes for A and B are Co-dominant and are thus are both expressed in a person who has both. A and B are also dominant over the O type, so any person with O blood type must have inherited O from both their parents. The parents in the question must both be carrying the O allele which is not expressed because A and B are dominant over it. The child could then inherit one O allele from each parent producing a blood type of O.

Answer 3

No. One parent would have to have a B allele in order for the baby to inherit a B allele. The genotypes for blood group A are AA or AO. The genotype for O is OO. So neither parent in this case would have a B allele to pass on to a baby. With the two parents in this case, only a type O or type A baby is possible.

Answer 4

Yes. Both parents would have to be heterozygous AO and BO and then pass on their O alleles to their O positive child.

Answer 5

Yes.

Answer 6

no