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Blood Type B

The genotype (allele combination) of a person with blood type B could be BB or BO. Based on the law of independent assortment, the allele combinations BB and BO will be separated eqally during meiosis. In other words, for a male with blood type B and alleles BO, 50% of his sperms are genotype B, and 50% are genotype O, while 100% are B if he has alleles BB. For female, the eggs have the same pattern. Children of two blood type B parents may have 93.75% frequency to be blood type B (BB or BO genotype), and 6.35% frequency to be blood type O (OO genotype). For detailed calculation, see Blood Type Calculator page.

Children Blood Type Frequency Chart

• Blood type B + B:
 Parent Blood Type (B) B (75%) O (25%) ParentBloodType (B) B (75%) B/B (56.25%) B/O (18.75%) O (25%) O/B (18.75%) O/O (6.25%)
Children Type B (BB, BO) = 56.25% + 18.75% + 18.75% = 93.25%
Children Type O (OO) = 6.25%

• Blood type B + A:
 Parent Blood Type (A) A (75%) O (25%) ParentBloodType (B) B (75%) B/A (56.25%) B/O (18.75%) O (25%) O/A (18.75%) O/O (6.25%)
Children Type AB = 56.25%
Children Type A (AO) = 18.75%
Children Type B (BO) = 18.75%
Children Type O (OO) = 6.25%

• Blood type B + AB:
 Parent Blood Type (AB) A (50%) B (50%) ParentBloodType (B) B (75%) B/A (37.5%) B/B (37.5%) O (25%) O/A (12.5%) O/B (12.5%)
Children Type B (AB,BO) = 37.5% + 12.5% = 50%
Children Type A (AO) = 12.5%
Children Type AB = 37.5%

• Blood type B + O:
 Parent Blood Type (O) O (100%) ParentBloodType (B) B (75%) B/O (75%) O (25%) O/O (25%)
Children Type B (BO) = 75%
Children Type O (OO) = 25%

ABO blood group system can be used together with Rh blood group system, the later can be + or -. Blood type B can be B+ or B-.

Blood type B+ can accept blood from B+, B-, O+ and O- Donor's red blood cell.
Blood type B+ can accept blood from B- and O- Donor's red blood cell.
Blood type B+ donor's red blood cell can only be accepted by B+ and AB+ recipients.
Blood type B- donor's red blood cell can be accepted by B+, B-, AB+ and AB- recipients.

Blood type B can accept blood from B and AB Donor's plasma.
Blood type B donor's plasma can be accepted by blood type B and O recipients.

Blood type B has higher frequency in Asia, East Europe, where about 20-30% population is type B. Blood type B is low in America, Australia and West Europe, where <10% of the population is type B.