Hematology is the study of

In which cells are the alleles for blood group expressed?

With regard to the $ABO$ blood typing system,if a man who has type $B$ blood and a woman who has type $O$ blood were to have children,what blood types could the children have?

Which $\text{WBCs}$ are phagocytic cells that destroy foreign organisms entering the body?

$A$ person with blood group $A$ needs a blood transfusion. Which blood group$(s)$ can be donated to them?

The name $Rh$ blood group is derived from