Chapter Chapter 1414

Blood GroupsBlood Groups

ABO Blood Group is ABO Blood Group is determined from determined from three alleles.three alleles.

Type AType A Type BType B Type OType O

Co-Dominant

Recessive

Human Blood Type

GenotypeGenotype PhenotypePhenotype

AA, AOAA, AO AA

BB, BOBB, BO BB

ABAB ABAB

OOOO OO

Human Blood GroupsHuman Blood Groups Rh Factor – type of protein on the Rh Factor – type of protein on the

surface of Red Blood Cellssurface of Red Blood Cells• Rh blood group is determined by a Rh blood group is determined by a

single genesingle gene with with two allelestwo alleles POSITIVE [Rh+, Rh+] or {Rh+, Rh-] POSITIVE [Rh+, Rh+] or {Rh+, Rh-] (Dominant)(Dominant)

NEGATIVE [Rh-, Rh-] NEGATIVE [Rh-, Rh-] (Recessive)(Recessive)

Blood cells have either “Blood cells have either “AA or or BB” ” antigensantigens on outside surface of blood on outside surface of blood cell or cell or NO antigensNO antigens, which gives you , which gives you blood type “blood type “OO”.”.

WRONG BLOOD TYPE???WRONG BLOOD TYPE??? If given the If given the

“wrong” blood type “wrong” blood type for medical for medical purpose, the purpose, the immune system immune system would recognize would recognize the blood cells as the blood cells as foreign and destroy foreign and destroy them!them!

We say the We say the universal donoruniversal donor is is Type OType O and the and the universal recipientuniversal recipient is is Type Type ABAB. . • However, Rh factor does matter!!!However, Rh factor does matter!!!

FYI…Blood TypesFYI…Blood Types Type O+ = 38.4 % most commonType O+ = 38.4 % most common Type A+ = 32.3 %Type A+ = 32.3 % Type B+ = 9.4 %Type B+ = 9.4 % Type O- = 7.7 %Type O- = 7.7 % Type A- = 6.5 %Type A- = 6.5 % Type AB+ = 3.2 %Type AB+ = 3.2 % Type B- = 1.7 %Type B- = 1.7 % Type AB - = 0.7 % most rareType AB - = 0.7 % most rare

Lets do a Punnett Square….Lets do a Punnett Square…. Cross a heterozygous Cross a heterozygous

type A mom with a type A mom with a recessive dad. Give the recessive dad. Give the possible genotypes and possible genotypes and phenotypes of the phenotypes of the offspring.offspring.

Genotype: Genotype:

AO 50%AO 50%OO 50%OO 50%

Phenotype:Phenotype:A 50%A 50%O 50%O 50%

A O

O

O

AO OO

AO OO