The number of alleles controlling blood groups in humans? by Sunday | Sep 7 | Biology JAMB | 0 comments A. 3 B. 4 C. 5 D. 2 Correct Answer: Option A – 3 Users Also Read These:A person with blood group B can only donate blood to…Which of the following statements is true of blood…During blood transfusion, agglutination could be…When both alleles in a heterozygous individual are…A woman with blood group A gives birth to a child…