A woman with 1 blood group, Rh negative married a heterozygous man, Rh positive with a 3 blood group.

A woman with 1 blood group, Rh negative married a heterozygous man, Rh positive with a 3 blood group. Determine the genotype and phenotype of children, the probability of having children with 1 blood group, Rh positive.

The first blood group J ° J °
Third blood group J ° J (B) or J (B) J (B)
It is said that a man is heterozygous, so the third is J ° J (B)
Rh positive – R
Rh negative – r

P: J ° J ° rr × J ° J (B) Rr
G: J ° r J ° R; J ° r; J (B) R; J (B) r
F1: J ° J ° Rr; J ° J ° rr; J ° J (B) Rr; J ° J (B) rr
1group 1group 3group 3group
Rh + Rh – Rh + Rh –

Only 4 phenotype variants
One (Rh +, 1 group) is suitable
1/4 = 0.25 – the desired probability