# A mother with blood group ${=}^{B'}$ has a fetus with blood group $-A'$ father is ${=}^{A'}$. Explain the situations?
Mother is heterozygous $B$ with the genotype $L_B L_O$ . Father would have the genotypes $L_A L_A$ . When the $L_o$ of mother and $L_A$ of father come together in the foetus, it results in the blood group $A$.