Question

An individual's ABO blood type can always be determined by an analysis of the blood. About 80% of the people in North America are known as secretors, in which the ABO type is also secreted into other body fluids such as saliva. About 20% of North Americans are non-secretors, so their saliva always appears to be type O, no matter their actual ABO blood type. Non-secreting is a recessive treat. The ABO locus on chromosome 9, while the secretor locus in on chromosome 19. A non-secretor man with type B blood and a secretor woman with type A blood have a child; the child is determined to be a non-secretor and have type O blood when the blood is tested. What is the probability that the next child born to this couple will be type A blood but type O saliva?

Answer 1

Since the parents are able to produce o blood group child & a non-becreto, we can conclude that I both the parents are heterozygous for A&B blood group & the mother is heterozygous for secuctor allele - olet the allele for Blood A, B &o be IA, Isa i respectivele • Let the allele for secuetoo be. 's & non secreto be's for Genotype of father: 'It' 'ss' I (9) Genotype of Mother: 'IB al so & First Cross! Iti Bi Secondcross is & & Gametes: It is al Gametes : s Offsprings: Tósa í đi Tei ü | Offspring: Ss un ds an Plu) blad group child - 1 - & & P(as) = 2 = 1 P (A blood group & non secreton). IXL darowy a non seer slxl.1 4 28