plz make me understand the blood groups of humans,ie which is dominant n which are recesssive briefly.
There are 4 blood groups in humans A, B, AB and O.
The blood group antigens are controlled by an autosomal gene designated I (isohaemaglutinin) which has 3 alleles IA, IB and IO. Allele IA is dominant over the allele IO and allele IB is dominant over IO .
Blood group Allele
A IAIA or IAIO
B IBIB or IBIO
In addition, the blood groups may be Rh +ve or Rh-ve, depending on the presence or absence of Rh factor in blood.