Before diving into the mystery, students must master the unique inheritance pattern of human blood types. The ABO blood group system is an excellent teaching tool because it demonstrates both and codominance . The ABO Alleles
| Phenotype (Blood Type) | Possible Genotype(s) | | :--- | :--- | | | IAIA or IAi | | Type B | IBIB or IBi | | Type AB | IAIB | | Type O | ii |
, etc.). Individuals with attached earlobes should be represented by shaded symbols to indicate the recessive phenotype. Coventry Local Schools Final Answer: The thief of the Wexford estate money is
), the lab might be flawed OR Joseph must carry the recessive lab activity blood type pedigree mystery answer key upd
Answer: A child with Type O blood must inherit a recessive
If your lab uses chemical simulations (such as using simulated blood with synthetic anti-A and anti-B sera), ensure students record their agglutination data accurately before they start drawing the pedigree.
The Punnett square shows a 25% chance for Type AB. Before diving into the mystery, students must master
If Baby X is Type O- and Baby Y is AB-, and the families are Smith ( ) and Jones ( The Smiths can have any blood type (A, B, AB, or O). The Joneses can only have Type A or Type B.
Because she has Rh- blood, her Rh genotype must be . Her ABO genotype could be IBIBcap I to the cap B-th power cap I to the cap B-th power IBicap I to the cap B-th power i Mr. Smith (A+): His Rh genotype could be . His ABO genotype could be IAIAcap I to the cap A-th power cap I to the cap A-th power IAicap I to the cap A-th power i Mrs. Jones (O+): Her ABO genotype must be . Her Rh genotype could be Mr. Jones (AB+): His ABO genotype must be IAIBcap I to the cap A-th power cap I to the cap B-th power . His Rh genotype could be Part 2: Pedigree Analysis & Punnett Squares Analyzing the Jones Family Options ABO Options: Mr. Jones ( IAIBcap I to the cap A-th power cap I to the cap B-th power ) x Mrs. Jones ( can only produce offspring with genotypes IAicap I to the cap A-th power i (Type A) or IBicap I to the cap B-th power i
). Her blood type is and she has attached earlobes , which matches the evidence found at the scene. Joseph’s blood type is determined to be B+ with the genotype BOcap B cap O . 1. Determining Joseph’s Genotype Individuals with attached earlobes should be represented by
The new key requires students to write out possible parental genotypes. For instance, if a mother is type A (genotype unknown) and a father is type B (genotype unknown), the key shows all four possible Punnett squares (A × B, A × BB, AA × B, AA × BB) before concluding that a type O child is impossible only if both parents are homozygous (AA and BB). This teaches that phenotype does not always reveal genotype—a critical lesson in genetics.
If you are using the updated version of this lab that includes the Rh Factor (+/-) , remember that positive ( ) is dominant over negative ( ). If Charles is negative (
To crack the case, you first need to understand the genetic rules of blood types. The ABO blood group system is determined by three alleles: IA , IB , and i . The i allele is recessive, while IA and IB are both dominant over i and are with each other. Here's a quick reference table:
Once the parent genotypes are established, perform the cross to determine the probability of the Claimant’s blood type.