Question

What blood type does a child inherit?

Answer 1

Blood grouping:

1. Blood types are defined on the basis of presence or absence of Rh (Rhesus) antigen on the blood.
2. If Rh antigen is present on the blood, blood is positive and if Rh antigen is absent on the blood, blood is negative.
3. There are eight blood groups such as: A+, A-, B+, B-, O+, O-, AB+ and AB-.

Inheritance of blood group:

1. Each parent i.e. mother and father give their offspring one of their two ABO alleles. ABO blood group is determined by the gene I.
2. Gene I has three variant alleles I^A, I^B and i. Alleles I^A, I^B are dominant over i.
3. If a child gets genes I^A and I^B genes from parents then the blood group is AB.

Genotypes and corresponding blood groups:

Blood Group	Genotype
A	IA IA and IA i
B	IB IB and IB i
AB	IA IB
O	ii