Question

Answer the highlighted questions

t should be a crime At 1:00 a.m., someone breaks a window in the back of a store and robs the safe. On the way out, the thief cuts himself (or herself) on a piece of broken glass. You are a forensic detective called to the scene. You test a sample of blood left behind by the thief. It is B+. While you are there, police bring in two suspects, each with a cut forearm, whom were arrested just three blocks from the store. You take a sample of each of the suspect's blood and label them Sample 1" and "Sample 2" Using Blood typing evidence alone, who can you eliminate from the suspect pool? Why? Sample # Anti-A SerumAnti-B Serum Anti-Rh (D) (rxn) Blood Type clumping -no clumping (rxn) Serum(rxn)

Answer 1

1. The suspect whose blood was marked sample 1 can be eliminated from the suspect pool based in the blood typing evidence.Since his blood sample clumped together in presence of both Anti-A and Anti-B serum and not in presence of anti-D serum,his blood group should be AB- . Supect 2's blood group matches to the criminal(B+).

2.From the table it is clear that Gen has B- blood group.If the father has type AB blood and the mother has type B blood,the child can have possibly A,B or AB blood group.This can be confirmed using a simple test cross table

Mother / Father	A	B
A	AA	AB
O	AO	BO

AO or AA genotype indicates type A blood,BO indicated type B blood,AB indicates type AB blood.Since the data on whether the blood groups of Candace and Dan are Rh+ or Rh- is not provided,we cannot confirm based on blood typing analysis alone of Gen is their daughter.However sample 3 is O+ and hence cannot be their child.